Systematic disinfection of the beer complex is a guarantee of excellent taste of the drink. The beer will not have an unpleasant odor, its color will be rich and bright.
Various solutions are used to disinfect brewing equipment. In our material today we will look at the most effective means, talk about their performance qualities and specific application.
Solutions used for disinfection of beer complexes
When working with brewing and bottling plants, the following products are used:
- Iodine. Disinfection with iodine is a simple and quick way to get rid of microorganisms. Preparation of the working solution will not cause difficulties. To do this you will need regular pharmacy iodine and water. The product is prepared in a clean container. For 10 ml of iodine, take 25 liters of cold water. Mix water and iodine until completely dissolved, then treat all working surfaces with the mixture. Iodine perfectly fights bacteria and protects equipment and containers from their subsequent appearance for a long time.
- Chlorine. Chlorine-based compounds destroy most microorganisms. With their help you can sterilize dishes, work containers, and specialized equipment. Chlorine is sold in soluble tablets. To prepare the solution, pour one tablet with 30 liters of hot or cold water. The main disadvantage of chlorine-containing disinfectant compositions is the need for subsequent rinsing. All treated surfaces will have to be washed. This significantly increases labor costs for disinfection.
- Acid. Disinfection solutions made on the basis of orthophosphoric acid. After using them, there is no need to wash the equipment or working surfaces. The product has a powerful disinfectant effect. It can be used to sterilize polymer beer containers, pipes, and connecting elements. Unfortunately, acid-based solutions are a scarce product for domestic buyers. They can only be purchased upon order.
- Hydrogen peroxide. Hydrogen peroxide solution is an effective assistant when carrying out disinfection work. It allows you to clean the beer bottling line with minimal financial losses. The product is prepared in the following proportion: 15 ml of peroxide per 20 liters of water. The composition is suitable for working with containers, hoses, and beer dispensing equipment.
- Alcohol. Using alcohol, you can instantly disinfect the surface. A significant disadvantage of this method is its high cost.
Sometimes hot water is used to clean dishes. A special solution is not prepared; bacteria are removed under the influence of high temperatures.
When carrying out disinfection measures, it is important to comply with the requirements of the regulations. It is unacceptable for working compounds to get into the beer. If trouble does occur, the spoiled batch of product should be disposed of immediately.
Now that your equipment is clean, it's time to sanitize it before use.
Only those elements that will come into contact with the wort after boiling need to be disinfected, namely: the fermenter and lid, water seal, rubber stopper, yeast starter flask, thermometer, funnel and siphon. Your bottles also need to be sanitized, but that can wait until bottling day. There are two very convenient ways to disinfect your equipment: chemical and thermal. When using chemical sanitizers, the solution can usually be prepared in a fermenter (fermenter) and all additional equipment can be soaked there. Heat treatment methods depend on the type of material you will use.
Chemicals
Bleach (Whiteness)
The cheapest and most accessible disinfectant solution, which is obtained by adding 1 tablespoon of bleach to 4 liters of water. Allow items to sit for 20 minutes and then dry them. Rinsing is apparently not necessary at this concentration, but many brewers, myself included, rinse with boiled water anyway to ensure there are no unpleasant chlorine odors.
Star San
Star San is an acidic sanitizer and was developed specifically for the sanitization of brewing equipment. It requires only 30 seconds of contact time and does not require rinsing. Unlike other no-rinse sanitizers, Star San will not affect taste at the recommended concentration of 30 ml per 20 liters of water. The solution can be placed in a spray bottle and used to spray glass containers or other items that need to be disinfected in a hurry. The foam product is also effective when immersed in the solution. Additionally, the surfactant used in Star San will not affect the head retention of the beer like those used in household detergents.
Star San has a long lifespan and will remain active for several days when the bucket is opened. And in a closed container its shelf life increases. Its viability can be determined visually; when it becomes cloudy the viability decreases.
Disinfectants based on peracetic acid (PAA)
These are professional acid disinfectants containing NAA and hydrogen peroxide. They are widely used in food industry enterprises. They can be purchased from specialized suppliers of cleaning chemicals. One example of such products is Oxidez from a Russian manufacturer, but there are similar analogues from other companies.
Since the concentrate is a very caustic substance with a pungent odor, you only need to work with it wearing rubber gloves, safety glasses and a respirator. Before use, prepare a 0.1-0.5% solution (10-50 ml of concentrate per 10 l. cold water). The resulting solution can be applied to the surface to be treated using any clean cleaning equipment, sprayer, or soak items in the solution for 20-30 minutes.
After disinfection, it is enough to allow the solution to drain well from the surface being treated. It is not necessary to wash it off, since in the prepared concentration it does not affect the taste properties of the finished drink, because NAA and peroxide decompose in beer into vinegar, water and oxygen, and if washing is carried out with non-sterile water, then there is a risk of introducing new microorganisms into the treated surface. During treatment in the presence of air, the solution also quickly decomposes, so it is not recommended to reuse it after application, and it will also be necessary to periodically reapply the solution if it has stagnated for more than four days in a storage container.
The disinfectant solution does not affect glass, plastic, stainless steel and aluminum, but with prolonged contact it can corrode copper and brass, so these materials must be treated with extreme caution.
Hydrogen peroxide
For homebrewers, there are more affordable hydrogen peroxide solutions available in 37%, 6% and 3% concentrations. Hydrogen peroxide is a very strong disinfectant that kills almost all microorganisms harmful to beer. A 6% solution is best suited for use, as it has a good disinfectant effect and is less dangerous to humans. If a 6% solution cannot be found, then you can dilute 37% in 5-6 parts of water.
The process of disinfection with the solution is the same as with a product based on NAA. The disadvantages are the same as those of NAA: it is caustic, can burn skin and eyes, is unstable, and cannot be reused.
Alcohol
Ethyl alcohol is a very powerful disinfectant that can destroy almost all beer pests in a few seconds. It is also usually always on the shelves of home brewers, distillers, and moonshiners. It does not have to be washed off with water if it does not contain impurities, since ethyl alcohol is not a foreign component in beer. It is safe for metal and plastic products with few exceptions, but these types of plastic are rarely used in home brewing.
The disadvantage is the high cost if purchased externally, and due to its high flammability and flammability, large manufacturers try not to use it.
When working with alcohol, it is important to know that the optimal concentration for use is a 70% solution. At this concentration, it better wets and kills bacteria. But it will also be effective at a concentration of 50 to 95%, only the exposure time will be a little longer. Spent alcohol can be reused during the next disinfection.
Iodine
The use of pharmaceutical iodine or iodophor to disinfect equipment is not recommended for two reasons. First, it is not the best disinfectant and runs the risk of leaving enough pests on the walls of the equipment that it could ruin your entire batch of beer. And secondly, at high concentrations of the solution, it can remain on the walls of the equipment and go into the beer, which will negatively affect its taste, and can also affect the progress of fermentation and the functioning of the yeast. Iodine is also difficult to wash off plastic equipment, coloring it an unusual yellow-orange color.
If other available disinfectants described above are not at hand, then this method of disinfection will also work. To implement it, you will need one bottle (10 ml) of pharmaceutical iodine diluted in 20 liters of cold water, and then keeping the items being treated for 30 minutes in the resulting solution.
High temperature processing
This is one of the few ways a homebrewer can actually sterilize an item. Why is sterilization necessary? Homebrewers who grow and maintain their own yeast cultures tend to sterilize their growth media to ensure the yeast is protected from contamination. When microorganisms are heated at a high enough temperature for a long enough time, they are killed. Both dry heat (oven) and steam (autoclave, pressure cooker or dishwasher) can be used for disinfection.
Oven
Dry heat is less effective than steam for disinfection and sterilization, but many brewers use it. The best place for dry heat sterilization is in your oven. To sterilize an item, refer to the following table for temperatures and times.
The specified time begins when the product reaches the specified temperature.
Although the durations seem long, remember that this process kills all microorganisms, not just the majority as with disinfection. To be sterilized, items must be heat resistant at specified temperatures. Glass and metal products are prime candidates for heat sterilization.
Some homebrewers bake their bottles using this method and thus always have a supply of clean, sterile bottles. Opened bottles can be covered with a piece of aluminum foil before heating to prevent contamination after refrigeration and during storage. They will remain sterile if they are wrapped.
One note: soda-lime glass bottles are much more susceptible to thermal shock and breakage than those made from borosilicate.
Autoclaves, pressure cookers and dishwashers
Typically, when we talk about using steam, we are talking about using an autoclave or pressure cooker. These devices use pressurized steam to sterilize items. Because steam heats up heat more efficiently, the cycle time for such devices is much faster than using dry heat. The typical amount of time spent sterilizing a piece of equipment in an autoclave or pressure cooker is 20 minutes at 125 °C at 1.3 bar (20 psi).
Dishwashers can be used to sanitize, but not sterilize, most of your brewing equipment, you just need to be careful not to warp the plastic items. Steam during drying effectively disinfects all surfaces. Bottles and other equipment with narrow openings should be cleaned first. Run the equipment through the entire wash cycle without using any dish detergent or dryer softener. Dishwasher softeners that linger on your glasses can ruin your beer's foam. If you are pouring your beer after carbonation without a head of foam, this could be the main reason.
Table 2 - Summary table of disinfectants
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About specific problems with disinfectants
Along with a couple of jars of malt extract and a plastic fermenter, there are usually a few other things that come into the homebrewer's life. Most often, “this” takes the form of large white tablets, which are most directly associated with the sad need to disinfect simple beer equipment every time. A novice brewer, say from Barnaul, begins to think seriously about what these tablets are and what they are called only when they run out, and he is faced with the full problem of where he can find exactly the same ones nearby. It will soon become clear that this may not be such a simple matter. However, sooner or later, somewhere and somehow you will still be able to find something similar. True, in the future it may turn out that, unlike the previous ones, these new tablets can give the fermenter a surprisingly pungent and persistent smell of bleach, which, it seems, cannot be eliminated by absolutely nothing.
Perhaps the brewer, realizing the lack of knowledge about various types of disinfectant tablets, will show curiosity and turn to serious specialized literature. There he will find a great variety of very intricate names for various means, all of which are used for disinfection, and from such an abundance of possibilities he may become very confused. Moreover, it is guaranteed to happen if, guided by a completely understandable desire to find something suitable, our brewer begins to study brief descriptions of the various beneficial properties that all these mysterious substances have, the existence of which he could not even imagine.
Home-beer lovers who are familiar with foreign languages have an alternative option to turn to foreign publications or Internet sites for home brewers. There, a domestic brewer can find lively stories about how good and convenient it is to use this or that product, from this or that company, especially in half-liter or liter canisters, so convenient for home use. I am far from the idea of saying that, say, in Barnaul it is impossible to find at least some analogues from the list of foreign abundance. Some things are, of course, possible. Only the minimum volume of the canister in this case will be 25–30 liters, and not everyone may have the desire to carry this into the house.
Among the various intricate names of disinfectants, an inquisitive brewer has probably already come across the cute word “iodophor” somewhere. Moreover, between long discussions about “surfactants that work as solubilizers,” he might not have paid attention to the information that the active ingredient of these fashionable drugs is iodine. Yes, yes, the most ordinary iodine, which can be bought at any pharmacy around the corner. Moreover, the disinfecting ability of various branded products is no more and no less than that of pharmaceutical iodine. It is believed that iodophors are simply more convenient to use. But in his specific circumstances, a domestic brewer may not attach importance to these advantages, which in his eyes will rightly fade behind a whole host of insoluble problems associated with the search and purchase of inexpensive iodophors in a particular provincial city (and in the capital too).
Terrible suspicions
The author of these lines did not immediately understand that iodine from a pharmacy is a very convenient and effective solution to the problem of disinfection in home brewing, although quite a lot of interesting articles have been written about iodophors. It states in an accessible and popular form that iodine is a good disinfectant, effective against a wide range of microorganisms. The concentrations of working solutions (and, therefore, the consumption of funds) are not high - only 10–12 ppm of active iodine (10 parts per million). In the articles you can also find that 60 seconds is enough for iodine to do its job of disinfecting equipment.
Now it’s difficult to say why I initially developed some aversion to iodine as a good disinfectant. One thing is certain - the problem of rinsing raised particular doubts. The fact is that many articles stated: iodine preparations are convenient and preferable not only due to their low consumption and, therefore, low cost of processing, but most of all due to the fact that after their use the equipment does not need to be rinsed with water.
What was the source of my distrust? I reasoned something like this. Both chlorine (which I already had experience using) and iodine are related chemical elements - halogens, that is, very active and potentially hazardous substances. Why does the fermenter need to be rinsed with water after treatment with bleach, but not after iodine? On the other hand, I, naturally, came across some information about the benefits of iodine for the human body, which I had never heard about chlorine.
However, in the above-mentioned articles for brewers and in the sections of books devoted to iodophors that I came across, such meager information was given about iodine itself, its compounds, influence on living cells and the human body that it turned out to be completely impossible to understand thoroughly the issues of usefulness and harmfulness business. Agree, to become a strong supporter of the idea of not rinsing the fermenter after treating it with a product that kills living cells, you need to have good reasons.
Reports about the speed of action of iodophors aroused no less suspicion in me. In my deep conviction, statements that complete disinfection of the fermenter with iodine preparations occurs within 60 seconds are without any basis. But let's not get ahead of ourselves. We still have a detailed conversation about antimicrobial activity.
In order to fill the information gaps in publications for brewers and to somehow understand all the questions that arise, the author of these lines undertook his own small research of a wide variety of sources: from scientific articles and technical reports to chemistry textbooks. The results of his efforts are outlined below.
Iodine and the human body
Probably everyone knows at least two things: that iodine is most often used externally for medical purposes and that iodized salt is very useful for residents of continental regions of the globe, because they suffer from a lack of iodine in the body. Whatever one may say, it is quite difficult to draw any conclusions from these two well-known truths regarding the rules for using disinfectant iodine solutions in home brewing. Some additional information is clearly required here.
As mentioned, iodine belongs to a group of substances called halogens. On the one hand, in terms of reactivity, iodine is the least active halogen, but it is still a halogen and therefore chemically active enough to not be found in free form in nature. All halogens, including iodine, are found in the form of salts. Sea water, for example, contains approximately equal amounts of iodides (salts of hydroiodic acid) and iodates (salts of iodic acid).
It is in the form of salts that iodine is found in food products and drinking water. In iodized salt, for example, iodine is most often present in the form of potassium iodate. In this case, iodate during the preparation of food, and then in the digestive system, quite quickly turns into iodide, which is easily absorbed in the anterior sections of the small intestine. From the intestines, potassium iodide passes into the blood plasma, from where it is greedily absorbed by the thyroid gland. It is believed that potassium iodate in large doses is less useful than iodide, but in small doses it is perfectly absorbed human body.
Pure iodine is undoubtedly poisonous. Even the usual iodine tincture from a pharmacy, when inhaled its vapors, affects the upper respiratory tract, and if ingested, causes severe burns of the digestive tract. Large doses of elemental iodine are dangerous: a dose of 2...3 g is lethal.
At the same time, in the form of iodide (i.e. in its natural form), fairly large doses of iodine can be taken orally. If you introduce a significant amount of inorganic iodine salts into the body with food, their concentration in the blood can increase 1000 times, but within 24 hours after administration the iodine content of the blood will return to normal. However, large doses of such salts are not recommended to be taken regularly over a long period of time. It has been found that this can cause painful changes in the thyroid gland.
The BYO homebrewers magazine listed a daily iodine intake that may be considered dangerous at 0.75 mg per day. WHO (World Health Organization) experts suggested that iodine doses above 1 mg per day should be considered dangerous. In the UK, the threshold for hazardous consumption starts at 0.017 mg iodine per 1 kg of body weight, or more than 1 mg per day. It should be noted that for individuals with clinical symptoms of certain diseases, for example, hyperthyroidism, the indicated doses are excessively high and can lead to dire consequences.
Numerous studies of the effects of iodine compounds on the human body are most often associated with the problem of disinfection of drinking water. It turns out that in many countries of the world, iodine was chosen for these purposes, and not chlorine, as in Russia. Doctors carefully monitored the health of American soldiers, peace corps activists, prisoners, patients taking various drugs, astronauts, schoolchildren and others who drank iodized water regularly over an extended period of time. The results of these studies formed the basis for the above iodine intake, which can be considered very well founded. Although, as we have already seen and will see below, some variations of this norm are possible.
This may seem strange to some, but I want to give examples of the use of iodine to disinfect equipment - tanks, pipelines and their contents ... from the US space program, which presents a very convincing picture. Moreover, the disinfection techniques themselves, and the technical devices intended for this purpose, and the evolution of these techniques and devices on American spacecraft from Apollo to the Shuttle are very well described in various publications by NASA (US National Space Agency).
Iodine was first used to disinfect drinking water by NASA in 1969 in the lunar exploration program. Before the flight, the tanks in the lunar cabin of the Apollo spacecraft were filled with water enriched with elemental iodine - the concentration of I2 was 12 mg/l (12 ppm). While they took off, set course and flew towards the Moon, the concentration dropped to 0.5 mg/l. The astronauts drank this water. The same technique was used on the Skylab space station, with the only difference being that a solution of iodine and potassium iodide (1:2, with an iodine concentration of 30 ppm) was added to the water coming from the fuel cells and the iodine concentration in this water was maintained at level 0.5–6 mg/l.
The water supply system of the reusable spacecraft Shuttle was originally designed in approximately the same way. However, in 1997, NASA experts became concerned about the condition of the thyroid gland of American astronauts and installed special ion exchange and carbon filters to remove all forms of iodine from the spacecraft's drinking water. From that moment on, the diet on board was subject to the requirement of consuming no more than 0.5 mg of iodine per day.
What happened to the active and dangerous molecular iodine in the tanks of NASA spacecraft? Judging by the initial concentration of iodine, a disinfectant solution was poured into the tanks of the lunar cabin, capable of killing all living things both in the tanks and in the water itself. Why did the astronauts remain alive and well? And where did the iodine go? Here and there in articles for home brewers you can find statements about the “volatility” of iodine. But it could hardly “evaporate” from the tanks of a spaceship, even if it had such an ability. Iodine, unlike, for example, chlorine, is not very volatile. Under normal conditions, chlorine is a gas and, accordingly, can volatilize from solutions. Iodine at atmospheric pressure and room temperature is a solid and can volatilize—sublimate—if it is heated well. Iodine melts at 113.5 °C and boils at 184 °C.
In order to understand the iodine solution in the tanks of the lunar cabin, we will have to delve a little deeper into chemistry. Moreover, this chemistry will be quite modern - some of the results given below were obtained in scientific laboratories at the turn of the 1990s and 2000s.
A little chemistry
It is known that iodine is poorly soluble in water; at 25 °C the solubility is 0.3395 g/l. True, if we take into account the working concentrations of iodine in disinfectant solutions of 10–25 ppm, then the solubility in water does not seem so low.
In an aqueous solution, iodine participates in various chemical transformations. As a result, a whole set of compounds is formed:
I - , I 2 , I 3 - , I 5 - , I 6 ², HOI, OI - , HI 2 O - , IO 2 - , H 2 OI + .
Their antimicrobial activity is different and has not been fully studied (hence some differences in recommendations on the concentrations and time of destruction of microbes). However, according to many researchers, the main role is still played by molecular iodine – I 2 . The antispore effect of I 2 is 2–3 times higher than HOI, but HOI is 40 times more active against viruses. OI- and other compounds are considered biologically inactive. I 3 - , I 5 - are complexes of iodide ion (I -) and molecular iodine (I 2), where I 2 is also the antimicrobial component.
The concentrations of iodine compounds in an aqueous solution depend on various factors, primarily from the initial concentration of iodine itself, the pH factor and temperature of the solution, the presence of iodides and bicarbonates in water also has an effect. For disinfection, it is very important that the equilibrium concentrations and composition of the solution also depend on the time that has passed since the dissolution of iodine. This is due to the fact that some chemical reactions occur very quickly, from an everyday point of view - instantly. Others, on the contrary, are very slow - according to chemical concepts. In the same way, the composition of the solution is the same immediately after dissolution, but after some time (depending on the temperature) it is completely different. At both stages of the process, the pH factor plays an important role.
Immediately after dissolving iodine (fresh solution) at pH< 6 присутствуют только I — , I 2 и I 3 — . При pH 8–9 и низкой концентрации растворов (c(I2) < 10-5 M), HOI составляет 90% общей активности. Только при pH >10 IO - and I 2 OH - begin to predominate.
Scientists and NASA specialists conducted complex computer calculations (taking into account thirteen chemical reactions) for both stages. As a result, the following picture was obtained. Let the pH of the water be equal to 7 (neutral reaction). If 2 mg/l of iodine is added to such water, then immediately after dissolution the concentration of active molecular iodine (I 2 ) will decrease slightly, approximately by half, and a corresponding amount of I - and I 2 OH - ions will appear. Concentrations of other substances, such as hypoiodic acid (HIO), will be at the level of 0.001 mg/l. Thus, you will get a quite decent disinfectant solution capable of killing living cells. After some time (the duration depends on the temperature), the picture will change. The concentration of active molecular iodine will drop to 0.001 mg/l, and the solution will contain mainly iodide (I -) and iodate (IO 3 -) ions. In combination with hardness salts (positively charged magnesium and calcium ions) dissolved in water, you get a completely harmless solution, the excessive and regular use of which can only lead to a slight enlargement of the thyroid gland in a healthy person.
The color of iodine is black-gray with a violet metallic sheen. The color of the vapor is dark purple. In different solvents, iodine has a different color: in water it is yellow, in gasoline, carbon tetrachloride CCl 4, and in many other so-called “inert” solvents it has purple- exactly the same as iodine vapor. A solution of iodine in benzene, alcohol and a number of other solvents has a brown-brown color (like iodine tincture); in an aqueous solution of polyvinyl alcohol (–CH 2 –CH(OH)–)n, iodine has a bright blue color (this solution is used in medicine as a disinfectant called “iodinol”; it is used to gargle and wash wounds).
Iodine salts - iodides - are generally colorless and look like ordinary table salt, only some of them have a slightly yellowish tint. Aqueous solutions of these salts, as well as solutions of hydroiodic and iodic acid, are colorless.
Let's now remember what happens to the disinfectant solution of iodophor or iodine tincture from the pharmacy (if you already have experience using them)? Yes, yes, its color gradually fades and soon disappears completely. What happens to the iodine? What happens to it is what should happen and what was shown above - iodine in solution transforms into the normal form of its existence in nature - iodides and iodates.
Now is the time to remember the problem of rinsing equipment after treatment with iodine. As is easy to see, everything seems to be in order with this - iodine in an aqueous disinfectant solution gradually turns into a form quite digestible for the human body - iodide. And that huge amount of water: 999,975 mg for every 25 mg of iodine salts - can be a completely normal rinse for the fermenter. In any case, 25 mg of bound iodine is certainly no worse than 350 mg of chlorides allowed by sanitary standards for the content of harmful substances in one liter of drinking water. Iodine salts will even be useful in those moderate doses, in which they can remain on the walls of the fermenter and get into the beer.
Of course, all these chemical transformations of iodine do not occur in 30 seconds. There is evidence that hypoiodic acid (HOI) can be present for a very long time in drinking water treated with iodine, from 10 to 1000 days. At the same time, it is capable of reacting with organic matter, forming organoiodines, which are often associated with problems with the aroma and taste of drinking water. However, the equilibrium concentrations of HIO are small, and beer has its own distinct taste, so such problems may not arise; it all depends on the individual characteristics of the consumer.
Concentration of working solutions and duration of disinfection
Let's return to the issue of the activity of iodine preparations against microorganisms. Brewers are interested in two questions: what concentration of disinfectant and what contact time are required to completely kill all microorganisms harmful to beer. Unfortunately, there is no simple and correct answer to this question. There are several reasons for this. The most important thing is that every living creature requires an individual approach. The second is due to the fact that pest microorganisms hide in various hard-to-reach places, for example in particles of dirt. The third relates to the disinfecting properties of iodine solutions, which may depend on various parameters, such as pH and solution temperature.
Let me give you a couple of examples. Breweries have these huge devices called tunnel pasteurizers. There, beer bottled or barreled is kept for a certain time at a certain temperature. This is done to kill bacteria and remaining yeast in the beer. Processing standards are scientifically based. But here’s the problem: some bacteria may end up in a lump of yeast corpses and survive, and even be provided with food. Wild yeast spores are not identical in vitality to vegetative cells. There is experimental evidence of the survival of these spores in pasteurizers set to live cells.
Let's look at other examples. The literature provides the following data. Cheng & Levin (1970) report that the time to kill 90% of Aspergillus niger spores is 0.86 min when exposed to an iodophor solution with an iodine concentration of 20 ppm, pH 3.0 (this is close to the stated 60 s.). In a sodium hypochlorite solution of the same concentration, a similar result was achieved in 1.31 minutes. at pH 7.0. Kurtzman & Hesseltine (1970) reported that 7 types of mold and 4 types of yeast were killed in a 1.25 ppm chlorine solution after 1 min of exposure. Perhaps the most interesting thing about these reports is that 10% of the spores can survive lethal concentrations of disinfectants for more than a minute. Therefore, it may take a longer period of time for 99.999% of cells or spores to die. Thus, for the relatively complete destruction of some living creatures (99.999%) in an iodine solution with a concentration of 14.6 ppm, it takes 10 minutes.
Thus, we can conclude: during the “60s” announced in some articles for home brewers. a certain percentage of microorganisms of one species, even those very sensitive to a given chemical, may survive. This conclusion applies to “clean” laboratory conditions in Petri dishes, where microbes have nowhere to “hide”.
In real beer equipment, microbes can “hide” in places that are difficult to reach for disinfection - micropores of old corks, under the sealing tape with which the fermenter tap is screwed, etc. For this reason, you should also not rush to pour out the solution and finish disinfection too quickly. It may take some time for the antimicrobial agent to “reach” the microbes themselves. This time is difficult to calculate accurately. It all depends on what exactly you are disinfecting. It can be argued that beer is unlikely to reach bacteria stuck, for example, on layers of sealing tape. It probably won’t get anywhere, just don’t forget that the beer will be in contact with this equipment for a week, and sometimes significantly more.
Traffic jams are a slightly different story. Cracks in old rubber may make it difficult for fluid to flow through. If you briefly treat the plug in a disinfectant solution, this will not give the desired antimicrobial effect. However, these pores are much more permeable to air, so the slightest leak in the external gas environment (say, when draining beer from the fermenter tap) can cause living microbes, as well as their spores, to enter from these refuges directly into the beer.
Above we discussed types of microorganisms sensitive to the effects of iodine. However, there are other options. Mold spores, called Byssochlamys fulva, feel great in a solution of iodine with a concentration of 445 ppm - within 40 minutes 100% of the spores remain viable and only after an hour 10% of them remain. Chlorine is about as ineffective. Byssochlamys fulva, fortunately, is not a beer contaminant and cannot grow in it, but it is quite common in nature (mold affects fruit). I provided this information as an example of how differently microorganisms can react to the same disinfectants.
For this reason, in various special articles and books you can find information that iodine is not a sterilizing agent and provides only an average level of disinfection. This means that iodine and its preparations are not able to kill all forms of microorganisms known to modern science, and this means the most resistant of them - spores of bacteria and molds. This is true. However, iodine is quite suitable for brewing. Because it is very effective against microscopic life forms that can develop in beer. We must not forget that beer itself is a completely special environment in which many forms of microorganisms, such as molds and spore-forming bacteria, simply do not develop. Mold needs oxygen, and in beer quickly inoculated with a large amount of yeast, there will clearly not be enough of it for mold to develop. Bacterial spores cannot germinate at pH values less than 5 units. So keep an eye on the beer parameters. If they are normal, then microbes will have a hard time there. But, unfortunately, not everyone.
In brewing, there may be situations where average level disinfection is not enough. However, all of these examples refer to the process of propagating pure yeast cultures, where a single yeast cell is grown into the billions of cells needed to pitch wort. At the same time, the requirements for sterility and cleanliness are completely different. In these situations, a completely different sterilization technique is used, and, of course, iodine preparations are no longer suitable to achieve such high standards. The reason is already known - the extreme resistance to iodine of spores of some types of mold, which can successfully develop on the surface of nutrient media in Petri dishes and in test tubes on slanted agars, since both of them are in direct contact with air.
Technique for disinfecting household equipment with pharmaceutical iodine
Pharmaceutical iodine solution is dispensed in small 10 ml vials, which is very convenient for disinfecting equipment used in home brewing. The solution contains 5% active molecular iodine (I 2), half a gram per bottle. This amount is enough to prepare 40 liters of disinfectant solution with a concentration of I 2 12.5 ppm or 25 liters with a concentration of 20 ppm. When choosing the volume of water, you need to proceed from two considerations. Firstly, the iodine concentration in the solution should not be less than 10–12 ppm. Secondly, when iodine is dissolved in neutral water (pH = 7), approximately half of the active molecular iodine is immediately converted into iodide and iodate ions, which are harmless to bacteria. Therefore, if you dissolve a bottle of pharmaceutical iodine in 25 liters of water, you will get an excellent disinfectant solution that can kill any living creature dangerous to beer.
The main thing is not to pour iodine into hot water, otherwise, instead of a disinfectant solution, you will quickly get a harmless solution of iodine salts, in moderate doses, which are, however, very beneficial for health. Room temperature or cold tap water temperature will be quite suitable for disinfection needs. I would advise not to add iodine to water that has just been poured from the tap, let it sit, let the free residual chlorine evaporate a little first, then you can add iodine.
Take your time to pour out the disinfectant solution. Keep it in your container for at least half an hour. If you haven't filled it to the brim, shake or rock it regularly so that the solution constantly wets the entire inner surface. Small parts of equipment, such as plugs and taps, pose an additional threat; microorganisms have somewhere to “hide” there. Soak them in disinfectant before attaching them to the fermenter. There is no need to rinse equipment with water after disinfection with iodine. You can even taste the remaining solution. But it is better to carry out such an experiment the next day after dissolving the iodine, and this should under no circumstances be done if you have any disease related to the thyroid gland and its function.
To get a dose of iodine compounds that is dangerous for the thyroid gland of a healthy body, you need to “drink” 30 ml of a disinfectant solution every day (with an iodine concentration of 25 ppm) for a fairly long period of time. However, if you drink beer every day and it contains residual disinfectant solution, then you will receive iodine regularly. Let's look at the different options. Although 30 ml doesn’t seem like a lot, just two tablespoons, but where can they “hide”? No one will leave that amount in a bottle, at least ten to twenty times less. If you treat the fermenter with a disinfectant and then empty it over the edge, no more than a teaspoon will remain inside. If you fill it to the brim and drain it through the tap, then, of course, there will be more left. However, if you multiply the dangerous dose by 24 liters (assuming that you drink a liter of beer per day and the batch has this volume), then you need to leave 720 ml in all fermenters (primary, secondary and bottling), i.e. it turns out 240 ml for each treatment. It's a glass! Also unlikely. Even if two to three milliliters remain in the bottles, it is difficult to obtain a dangerous dose.
But these are doses that are dangerous to health. To sleep peacefully, you need to stay within the “useful” dose (after all, the body receives iodine from other sources - salt, seafood). As a basis, you can take, for example, the iodine content in Novokuryinskaya PREMIUM water - 0.04–0.06 mg/l. This is already ten times less than the dangerous dose (and almost coincides with the body’s daily requirement of 100 mcg). Therefore, with each treatment of the tanks, no more than 24 ml of solution (one and a half tablespoons) should remain. It is also better to carefully pour everything out of the bottles.
Iodine colors the disinfectant solution yellow, which is good, because by the intensity of this color you will soon be able to determine the suitability of the solutions for disinfection. Iodine also stains the plastic of equipment, but this is not scary and even convenient - particles of dirt on the surface of the fermenter will have a more intense color, and you can easily detect and eliminate them as a potential source of infection.
Sanitary rules and regulations require that the pH value of drinking water vary within the range 6 ≤ pH ≤ 9. For disinfection with iodine, water with a neutral or slightly acidic reaction is required (this issue will be discussed in more detail in the next section). Therefore, you need to determine the pH factor of your tap water at least once - it is important that it is not noticeably higher than 7. Indicator paper may well be suitable for this. It is very inexpensive and can be purchased at any laboratory equipment store. If the indicator strips remain yellow or become pale green, then everything is in order, if the green color becomes very saturated, then the water has an “alkaline” reaction - it is best to “acidify” such water in any way known to you.
pH of iodine disinfectant solution
In articles and books about disinfection, you can find advice to acidify the disinfectant solution with iodine to pH=5. In recent articles about iodophors, on the contrary, it has been argued that these drugs work great without acidification. What's all this talk about acidity? What is their reason? It lies in the residual concentration of free molecular iodine in an aqueous solution of a disinfectant. As already mentioned, it is this iodine that plays a leading role in disinfection and its concentration after dissolution in water is very sensitive to the pH value.
Above was an ideal picture characteristic of a strictly neutral aqueous solution of iodine (pH = 7). In this situation, immediately after dissolution in water, a fairly high concentration of molecular iodine remains (about half of the dissolved amount), and the solution has high antimicrobial activity. At the end, the concentration of free iodine decreases noticeably (almost 1000 times), and the solution mainly contains iodides and iodates that are completely safe for health. It is for this reason that it is believed that a pH value close to 7 is best suited for the disinfection of drinking water. Iodine in such a solution actively kills microorganisms and eventually self-neutralizes.
In real life, water can be either alkaline or acidic. Let us immediately note that at high pH values, the concentration of molecular iodine immediately after dissolution decreases very much and proper antimicrobial effectiveness cannot be expected from such a solution. The values of the concentration of molecular iodine for various pH values are given in the table (for the starting concentration of iodine in a solution of 2 mg/l). The table shows two concentrations - immediately after dissolution and equilibrium, which will remain in solution after a fairly long (and sufficient for disinfection) time, which depends on temperature.
It is easy to notice that with increasing acidity, the final content of active molecular iodine in the solution stabilizes and can remain high for quite a long time. After disinfection is completed, in this case, there may be a problem in removing active free iodine, which can cause an allergic reaction in some people. For example, various methods are proposed for removing iodine from blood serum after disinfection of blood substitutes or donor blood with solutions of iodophors. For these purposes, various adsorbent substances are used: starch, corn oil and others. Adsorbents “interact” with free residual iodine and do not in any way affect the content of iodine salts.
Beer, of course, is not blood for transfusion, and there are significantly fewer opportunities to cause allergies, but any brewer still has the right to ask the question: how much free iodine will remain in the beer, say, a month after treatment of the fermenter, and whether this can have any consequences? -are there harmful consequences?
Let's first calculate how much I 2 can get into the beer after disinfecting the equipment with an acidified solution (pH=6). We have already estimated that beer should not contain more than 0.06–0.10 mg of all forms of iodine originally used. Calculations show that at pH=6, the residual free iodine in the solution is approximately 0.1 of the original amount. Thus, its concentration in beer is unlikely to exceed 0.006–0.001 mg/l; most likely, it will be even less.
Let me remind you that the American astronauts on the Moon were given not only a drink in which a little disinfectant solution remained (0.006 mg/l), but this same solution with a residual concentration of molecular iodine of 0.5 mg/l. The home brewer is still in a more advantageous situation, isn't it? But that's not all. The fact is that free iodine interacts very actively with various substances of organic origin - remember starch. Beer contains quite a lot of substances of this kind that can actively adsorb and inactivate iodine.
The influence of beer on the biological activity of iodine is evidenced by such experiments. Disinfecting solutions of nine different iodophors were mixed with a small amount of beer, then the effect of the resulting compositions on microorganisms was tested. Very often, solutions became absolutely harmless to experimental yeast with the addition of only 5–6% of beer. Sometimes it was necessary to add 20–25%. In our case, there will be much more beer, and significantly less iodine solution. So free iodine will be completely inactivated. We can probably end here, assuring readers that the further evolution of iodine does not promise any unpleasant surprises for health. The result of these transformations will be the same iodine salts and their compounds, which in moderate doses are perfectly absorbed by the human body.
Perhaps someone will not want to stop there. In this case, an extremely sensitive starch iodine reaction can be proposed to test your own beer for the content of active iodine residues. This reaction allows the detection of very small amounts of iodine in aqueous solutions. For research, you need to leave a little of the used disinfectant and periodically add a drop of this liquid to the aqueous solution of starch. A blue color will appear if even an insignificant amount of iodine, 1 mcg or less, remains in the disinfectant solution. The same thing needs to be done with a drop of beer.
Comparison of the antimicrobial activity of various iodine and chlorine preparations
Brewers should be especially interested in the activity of manufacturer-recommended disinfectants against actual beer pests. Such studies have been carried out. Patricia J. Braithwaite of The Metal Box Co. Ltd. tested nine branded iodophors recommended by the manufacturer for disinfection in the food industry. Twenty-one strains of real wild yeasts and spores recovered from breweries were used to study their effects on microorganisms.
A few words about how iodophors are “structured”. In these preparations, iodine is weakly combined with a surfactant, which acts as a “courier” - it transfers the iodine molecule to where it is needed, as a result of which iodophor solutions burn and color less aggressively. Thanks to this feature, they have found wide application in medicine. For disinfection needs, surfactants also play a positive role - they facilitate the penetration of iodine into various “hard-to-reach” places, such as lumps of dirt. Therefore, it is believed that iodine preparations are more effective in combination with surfactants. At the same time, surfactants do not affect the mechanisms of the antimicrobial action of iodine and its compounds. At the microscopic level, everything happens exactly the same. Even the chemistry of iodine in aqueous solutions of iodophors obeys all the laws that were described above. Note that commercial iodophors often contain orthophosphoric acid, which provides the necessary high acidity (pH≤3) for their stability during storage.
The effectiveness of different disinfectants is often compared based on the “time to 10-fold reduction” in the population of living microorganisms. It turned out that for different iodophors this parameter varies within a very wide range - from 1.2 to 8 seconds (solutions with the same working iodine concentration of 25 ppm were used). As a result, after 50 seconds of treatment with some drugs, about 0.01% of wild yeast remained “alive,” while after using others, less than 0.001%. Products well buffered with phosphoric acid turned out to be more effective (most likely, they are simply “preserved” better). It should be noted that after a rapid decrease in the number of living cells in the first 20 seconds of treatment (from 1,000 to 10,000 times), the effectiveness of the drugs decreases. The next 20 seconds only add another 10x contraction.
Working conditions - pH and temperature of the solution - affect the effectiveness of the drugs. The table below shows the time of tenfold contraction (in seconds) for one of the iodophors (at an iodine concentration of 25 ppm).
The effectiveness of sodium hypochlorite turned out to be noticeably less at the same concentration of chlorine (25 ppm), which is clearly seen from another table:
Against wild yeast spores, both iodophors and hypochlorites are less effective. To reduce the number of viable spores tenfold, iodophor no longer requires 1.8 seconds (as is the case with active cells), but 18 seconds. After 60 seconds of treatment, about 0.1% of wild yeast spores survive in the solution.
From the data presented it is clear that an increase in temperature by 20 degrees can significantly increase the antimicrobial activity of chlorine. For iodine, temperature is less critical, although a slight increase in activity does occur. The influence of the pH value of the factor also turns out to be more noticeable for chlorine; iodine at pH=6 and pH=7 acts with almost the same force, only with a significant increase in the acidity of the solution (pH≤3.5) does the antimicrobial effect slightly increase, which is especially noticeable at elevated temperatures. So the above conclusion about pH values (≈ 7) being favorable for disinfecting household equipment is confirmed in this case.
Why iodine?
After all that has been said, apparently no one has any doubts that pharmaceutical iodine can be used with great success by home brewers to disinfect equipment. Let us repeat once again why this is so.
Firstly, this is one of the most affordable drugs - in any corner of the country it can be purchased at a very affordable price, almost around every corner, and its packaging seems to be specially invented for disinfecting the fermenter.
Secondly, this is a very effective product that can destroy any microorganisms that pose a danger to beer production (as studies show, more effective than chlorine compounds), you just don’t need to be fussy and rush to pour out the disinfectant solution.
Thirdly, almost any water that has a neutral or slightly acidic reaction (pH≈7) is suitable for preparing solutions.
Fourthly, free molecular iodine, which has high biological activity and kills microbes, gradually eliminates itself from the solution, turning into compounds that are well absorbed by the human body - iodides and iodates; Therefore, small residues of disinfectant in both the fermenter and the bottles are not at all hazardous to health, and the equipment does not need to be rinsed.
In conclusion, not without some regret, it should be noted that very interesting areas remained outside the scope of discussion. First of all, this is the wonderful world of iodine biochemistry, where debates do not subside, there are unsolved mysteries and much more that makes science so attractive to an inquisitive mind. Somewhere out there there are still undiscovered clues to the antimicrobial action of iodine, the secrets of its transformations organic compounds in various organs and tissues, the mysterious effect of another very rare element - selenium - on the circulation of iodine in the body of animals and humans, and much more. However, an excursion to this vast and very interesting area is not yet included in the plans of the author of this article. “The trip,” of course, may take place in the foreseeable future, but that will be a completely different story.
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Bibliography
1. Iodophor, By Robert Arguello.
2. BYO (Jan, 2003).
3. Microbiology of beer. – 3rd ed. / ed. Fergus J. Priest and Ian Campbell. – St. Petersburg: Profession, 2003.
4. Iodine and disinfection: theoretical study on mode of action, efficiency, stability, and analytical aspects in the aqueous system / W. Gottardi, Arch Pharm (Weinheim). – 1999. –May; 332(5):151-7.
5. Hypoiodous acid: Kinetics of the buffer-catalyzed disproportionation / Y. Bichsel, U. von Gunten, Water research. – 2000. – Vol. 34, no12 – P. 3197–3203.
6. A Method of inactivating microbes in blood using iodin (WO/1994/006289).
7. The Destruction of Byssochlamys fulva asci by Low Concentration of Gaseous Methyl Bromide and by Apeous Solutions of Chlorine, an Iodophor and Peracetic Acid / K.A. Ito, Marcla L. Seeger, W.H. Lee, J. appl. Bact. – 1972. – 35, 479–483.
8. On the safety of iodine and potassium iodate. (Literature review) / G.A. Gerasimov: Accepted for publication by the journal “Clinical Thyroidology”, International Council for the Control of Iodine Deficiency Diseases (ICCIDD), Moscow.
9. Disproportionation Kinetics of Hypoiodous Acid As Catalyzed and Suppressed by Acetic Acid-Acetate Buffer, E.T. Urbansky, B.T. Cooper, D.W. Margerum. Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-1393. Inorg Chem. – 1997. Mar 26; 36(7), 1338–1344.
10. Use of Iodine for Water Disinfection: Iodine Toxicity and Maximum Recommended Dose, Howard Backer.
11. Reduction in the Iodine Content of Shuttle Drinking Water: Lessons Learned, Curt J. Wiederhoeft and John R. Schultz Wyle Laboratories, William F. Michalek UMPQUA Research Company, Richard L. Sauer NASA/Johnson Space Center. UMPQUA Research Company. – 1999.
12. Numerical Simulation of Iodine Speciation in Relation to Water Disinfection Aboard Manned Spacecraft I. Equilibria / James E. Atwater UMPQUA Research Company P.O. Box 609 Myrtle Creek, Oregon 97457, Richard L. Sauer NASA, Lyndon B. Johnson Space Center M/S SD4, Houston, Texas 77058, Jolm R. Schultz KRUG International 1290 Hercules Drive, Houston, Texas 77058. J. Environ. Sci. Health. –1996. – A31(8), 1965-1979.
13. Rakitin A.V. New disinfection and sterilization technologies at the present stage.
14. Iodophors as an aid to sanitation in beer canning plants /Patricia J. Braithwaite. Fd Technol. – 1973. – No. 8. – P. 269–281.
Food prepared with your own hands is tastier and healthier than that bought in a retail chain. This applies to drinks, canned foods and others.
Homemade beer
The history of beer consumption begins with ancient Egypt. Nowadays, beer has become one of the main low-alcohol drinks. But this drink for sale in stores is made using an accelerated procedure from concentrate. In order to extend its shelf life, preservatives are added to beer to kill the taste. If beer is your favorite product, then you can spend some time and other resources to prepare it at home.
Brewing equipment
To make your own beer you will need:
- an enameled or stainless steel pan with a capacity of 30-50 liters;
- a chiller or, more simply, a coil necessary for cooling beer;
- a container with a water seal of appropriate volume for the fermentation process;
- thermometer;
- mill for grinding barley or rye malt;
- accurate scales.
Brewing Ingredients
To make beer at home, you need the following ingredients:
- malt;
- hop;
- Brewer's yeast.
And, in addition to all the ingredients, it requires a lot of patience. Although you can prepare malt yourself, if possible it is better to purchase it at the store.
Brewer's laboratory
In order for yeast (which is a living organism) to germinate well, sterile conditions are necessary. Therefore, it is necessary to create sterile conditions using laboratory glassware. You will need hoses and brushes for washing bottles. Glass test tubes, flasks, stands for flasks with a round bottom are required. Brewer's laboratory can be replenished with necessary items in our store.
Homemade moonshine - a pleasant meeting
To distill moonshine at home, you need to purchase moonshine stills, for example, in our store. The store offers all kinds of devices. Here are devices with two and one steam chamber, copper devices. They also have different volumes.
Items for making wine and canning
To make wine you will need oak barrels different capacities. All products are made from oak that has been dried. There are barrels with a capacity from three to twenty-five liters. Our barrels will allow you to age wine in them, which will have a delicate taste. It will be stored in them for a long time.
For canning in jars, the household must have autoclaves with heating elements. Autoclave heating element will allow you to effectively process jars when preparing and canning berries, meat, vegetables, and other products at home.
Home-prepared beer, wine, and other drinks and products are always of excellent quality
This preparation requires patience. In addition, you will need brewing equipment, other items that can be purchased from us. Our managers are ready to advise upon your first request and help with the choice brewing ingredients, complete the purchase and deliver the purchased items.
First of all, before we talk about purity and sterilization, let's look at the history of beer purity.
Many people have heard about the so-called “Bavarian Beer Purity Law” (Das Reinheitsgebot), but few have read it in its entirety. Associated with this is the misconception that he primarily regulated the composition of “real” beer, creating the well-known formula - “malt, hops and water.” And virtually all beer brewed in Germany states that it was brewed in accordance with this law. Let’s not go into the wilds of this law, but let’s focus on the “classical” interpretation, Malt (grain), Hops and water. These are the main components of any beer.That is, any beer must consist of three components. But as you read in the last issue, I said that in addition to malt and fermentation containers, we will also need sugar and yeast. Yeast to ferment our beer. I don’t know how they brewed beer there in the old days. Because I don’t have sources to read. But, I would like to return once again to the last issue and invite you to watch a short video from the Teddy Beer beer company.
Note that at 1:11 the sterilizing solution is shown. Why is it needed, you ask? There will be a lot of letters below, but if you still want to master making homemade beer, please master everything.
Along with a couple of jars of malt extract and a plastic fermenter, there are usually a few other things that come into the homebrewer's life. Most often, “this” takes the form of large white tablets, which are most directly associated with the sad need to disinfect simple beer equipment every time. A novice brewer, say from Barnaul, begins to think seriously about what these tablets are and what they are called only when they run out, and he is faced with the full problem of where he can find exactly the same ones nearby. It will soon become clear that this may not be such a simple matter. However, sooner or later, somewhere and somehow you will still be able to find something similar. True, in the future it may turn out that, unlike the previous ones, these new tablets can give the fermenter a surprisingly pungent and persistent smell of bleach, which, it seems, cannot be eliminated by absolutely nothing.
Perhaps the brewer, realizing the lack of knowledge about various types of disinfectant tablets, will show curiosity and turn to serious specialized literature. There he will find a great variety of very intricate names for various means, all of which are used for disinfection, and from such an abundance of possibilities he may become very confused. Moreover, it is guaranteed to happen if, guided by a completely understandable desire to find something suitable, our brewer begins to study brief descriptions of the various beneficial properties that all these mysterious substances have, the existence of which he could not even imagine. Home-beer lovers who are familiar with foreign languages have an alternative option to turn to foreign publications or Internet sites for home brewers. There, a domestic brewer can find lively stories about how good and convenient it is to use this or that product, from this or that company, especially in half-liter or liter canisters, so convenient for home use. I am far from the idea of saying that, say, in Barnaul it is impossible to find at least some analogues from the list of foreign abundance. Some things are, of course, possible. Only the minimum volume of the canister in this case will be 25–30 liters, and not everyone may have the desire to carry this into the house. Among the various intricate names of disinfectants, an inquisitive brewer has probably already come across the cute word “iodophor” somewhere. Moreover, between long discussions about “surfactants that work as solubilizers,” he might not have paid attention to the information that the active ingredient of these fashionable drugs is iodine. Yes, yes, the most ordinary iodine, which can be bought at any pharmacy around the corner. Moreover, the disinfecting ability of various branded products is no more and no less than that of pharmaceutical iodine. It is believed that iodophors are simply more convenient to use. But in his specific circumstances, a domestic brewer may not attach importance to these advantages, which in his eyes will rightly fade behind a whole host of insoluble problems associated with the search and purchase of inexpensive iodophors in a particular provincial city (and in the capital too).This may seem strange to some, but I want to give examples of the use of iodine to disinfect equipment - tanks, pipelines and their contents ... from the US space program, which presents a very convincing picture. Moreover, the disinfection techniques themselves, and the technical devices intended for this purpose, and the evolution of these techniques and devices on American spacecraft from Apollo to the Shuttle are very well described in various NASA publications.
Pharmaceutical iodine solution is dispensed in small 10 ml vials, which is very convenient for disinfecting equipment used in home brewing. The solution contains 5% active molecular iodine (I2), half a gram per bottle. This quantity is enough to prepare 40 liters of disinfectant solution with an I2 concentration of 12.5 ppm or 25 liters with a concentration of 20 ppm. When choosing the volume of water, you need to proceed from two considerations. Firstly, the iodine concentration in the solution should not be less than 10–12 ppm. Secondly, when iodine is dissolved in neutral water (pH = 7), approximately half of the active molecular iodine is immediately converted into iodide and iodate ions, which are harmless to bacteria. Therefore, if you dissolve a bottle of pharmaceutical iodine in 25 liters of water, you will get an excellent disinfectant solution that can kill any living creature dangerous to beer.
The main thing is not to pour iodine into hot water, otherwise, instead of a disinfectant solution, you will quickly get a harmless solution of iodine salts, in moderate doses, which are, however, very beneficial for health. Room temperature or cold tap water temperature will be quite suitable for disinfection needs. I would advise not to add iodine to water that has just been poured from the tap, let it sit, let the free residual chlorine evaporate a little first, then you can add iodine. Take your time to pour out the disinfectant solution. Keep it in your container for at least half an hour. If you haven't filled it to the brim, shake or rock it regularly so that the solution constantly wets the entire inner surface. Small parts of equipment, such as plugs and taps, pose an additional threat; microorganisms have somewhere to “hide” there. Soak them in disinfectant before attaching them to the fermenter. There is no need to rinse equipment with water after disinfection with iodine. You can even taste the remaining solution. But it is better to carry out such an experiment the next day after dissolving the iodine, and this should under no circumstances be done if you have any disease related to the thyroid gland and its function.Why iodine? Firstly, this is one of the most affordable drugs - in any corner of the country it can be purchased at a very affordable price, almost around every corner, and its packaging seems to be specially invented for disinfecting the fermenter. Secondly, this is a very effective product that can destroy any microorganisms that pose a danger to beer production (as studies show, more effective than chlorine compounds), you just don’t need to be fussy and rush to pour out the disinfectant solution. Thirdly, almost any water that has a neutral or slightly acidic reaction (pH≈7) is suitable for preparing solutions. Fourthly, free molecular iodine, which has high biological activity and kills microbes, gradually eliminates itself from the solution, turning into compounds that are well absorbed by the human body - iodides and iodates; Therefore, small residues of disinfectant in both the fermenter and the bottles are not at all hazardous to health, and the equipment does not need to be rinsed.
Frequently asked questions:
- Why do you still need to disinfect (sterilize) beer equipment? - To kill microorganisms that can harm the production of beer, and you will get BRAZH.
- Which parts of the equipment need to be disinfected? - All plastic parts + overflow hoses, taps and the like that have already been in contact with in the past.
- How can I disinfect 60 bottles, have you lost your mind? Should I create a bath of solution?
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Well, why a bath? Everything can be made easier. Buy this equipment:
Pour the solution into the cup, place the roll and press several times, the solution splashes into the inside of the bottle. Next you need to dry the bottle, for this you will need this dryer:
We dressed the bottles as if they were on a Christmas tree - they drained and dried. But I foresee a lot of swearing and curses addressed to me, for example, “... Mac Doc, scam, I still need to buy a bunch of all sorts of crap...”. No, my dears, everything can be done much simpler.
2 - Immediately soaked in the sink. In order to get rid of the label (there are no bacteria and yeast there, since the beer has been pasteurized and all microorganisms have been killed).
3 - Rinse and rinse well
4 - Place a regular piece of paper around the neck and squeeze it lightly.
5 - Place the bottle in the prepared storage box with the neck down.
6 - The water flows onto a piece of paper, and not onto the floor, the bottle is clean and ready for pouring, standing and waiting in the wings.
Fast? And you thought it was just experience!
The second point is if your bottle has already been rolled up by you.
1 - We drank beer.
2 - Wash thoroughly.
3 - Douse it with boiling water from a kettle, or maybe with iodine water.
4 - A piece of paper for the neck.
5 - In the box.
The glass is 99.9% free of microorganisms. Plus you disinfected it and left it to dry. All.
- I made beer, bottled it in plastic and glass bottles. With “plastic” mash, in glass there is normal beer. Why?
- How long should I sterilize (boil) beer caps?
- Strange question, boil it, fill it with disinfectant solution, basically sterilize it as you wish. I just ask you without fanaticism.
- I used TWO different disinfectants, and in the end my beer stinks of bleach, why?
- Forgive me, but where did you read that you need to use two means. There is a proverb, “... it’s better to be too late than not too late...” - so, in our case this proverb does not apply. Different chemical elements react with each other differently. Perhaps this caused a chlorine reaction that was not completely washed off. The rule is to disinfect with only one solution.
- Tell me, can the wort itself in the jar be spoiled?
- Everything happens in our life. Look at the expiration date, do not buy wort from the Chinese (they do not produce it), if the expiration date has passed (it happened to me once), do not be afraid, open the jar, add water and boil. I was fine.
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Question from grok -How is the sterility of the fermentation tank ensured?
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First of all, disinfect the fermentation tank, tightly close the lid, and there is a water seal with water on the top of the lid. That's all. The beer ferments, gas comes out, and no air gets into the interior. No "wild bacteria or yeast".
And finally, a song about beer:
And finally, after all the brainstorming about disinfection and the like, you will probably ask, “... why the hell did you tell us about the Bavarian purity of beer and the like in the beginning...”. Everything is very simple. Manufacturers have taken care of good quality wort (malt) for you - your main task is NOT TO SPOILE this wort, not to spoil it, so that it doesn’t end up being MARSH. Keep the process clean - it's not that difficult. The main thing is to want it.
Your Mc Doc
PS: The article used various sources previously found on the Internet and saved on the hard drive without attribution. I used some original (or previously reprinted) material.