How to collect brewer's yeast for the next batch. Washing yeast in home brewing

It turns out that reusing yeast is not a new trend at all. Norwegian researcher of the history of beer Lars Garshol said in his blog that it began in the Stone Age. We publish the translation of the material from Pivo.by.

You can often hear this phrase: “Before Pasteur, no one knew anything about yeast.” The opinion that yeast began to be used relatively recently did not appear yesterday. Even microbiologists adhere to this idea. Thus, the authors of the most important publication, who compiled the genealogical tree of yeast (Gallone et al, 2016), concluded that the two main families of brewer's yeast descended from the same ancestor around 1600 AD. e. However, there is direct evidence that mankind began to use yeast long before this time.

The earliest documents that reliably describe the brewing process date back to the 16th-17th centuries, and for their authors, brewer's yeast was by no means a novelty. They repeatedly mentioned this ingredient, they knew how to work with it, and there is nothing in these texts to indicate that the yeast was new at that time or that there is anything surprising in its use.

Take, for example, Denmark's first cookbook. It was compiled from earlier German works and published in Danish in 1616. The first recipe it gives is for baking bread, the second is a beer recipe, and it doesn't say anything about adding yeast. The authors took this fact for granted. So, the recipe says (translated from Danish):

“When adding yeast, make sure it is not too hot or too cold; their temperature should be slightly higher than the temperature of fresh milk.

There is no doubt that we are talking about yeast, since in their description the authors use the word gierd, from which the modern Danish gær is derived, meaning “yeast”. Curiously, in the original, this phrase begins with the words naar du setter gierd paa, and in the 20th century, Norwegian and Danish brewers used a similar expression å sette gjær på to denote the action of "adding yeast."

Note: In 1616, adding yeast was such an obvious step in the brewing process that it wasn't even specifically listed in the recipe. In addition, the Danish language of that time already had a term for yeast and even a whole phrase to describe the action of adding it.

If we turn to other sources from that period, we get similar results. So, Olaf Magnus in his book of 1555 recommends using "the waste of the brewing process to obtain new beer." Christoph Kobrer in 1581 devoted an entire chapter in his opus to how to reuse yeast, whether dried or wet. Andrew Boord wrote in 1542 that apart from malt and water, nothing should be added to beer except yest, barme or goddesgood, which are three synonyms for the word "yeast".

In other words, adding yeast to the brewing process was as common in 16th century Europe as it is today. Therefore, whenever mankind thought to add yeast to beer, it happened long before the 16th century. But when?

Let's think logically. Sigmund Gjernes showed me how to use a yeast preservation ring. You should soak the ring in yeast (in foam or sediment) added during the brewing process so that they settle on its surface, and then dry the ring. To reuse the yeast, you need to take a small amount of wort and dip the ring into it. Ready. This is literally all that needs to be done to effectively reuse yeast. From archival documents it follows that for these purposes, in addition to wooden rings, pieces of cloth, wooden sticks and even straw rings were quite successfully used.

Thus, since the Stone Age, people have had everything they need to reuse yeast. The only thing they needed was to figure out how to transfer the resulting yeast foam or sediment from one brewing process to another. You just had to think: “What if I take the yeast foam and add it to the new wort? Will I get new foam? Just try it to make sure it works.

Do not forget that spontaneous fermentation is a rather risky undertaking that can lead to the most unexpected results. In addition, this process is far from safe. Therefore, as soon as someone astute came up with the idea of ​​​​reusing the yeast residue from a previous batch of beer, it became clear to everyone that this method was much more optimal, which is why it, apparently, soon became quite widespread.

This, however, does not give us an answer to the question of when exactly this historical moment occurred.

In Viking and prehistoric times, beer was brewed to celebrate special occasions. It was such an important and integral element of the main celebrations in a person's life that it was simply unthinkable to hold them without beer. For example, the members of the artel got together, brewed beer together, and then celebrated this or that event for several days.

Anders Christensen noted that if the spontaneous fermentation method was used, the whole process would be very risky, since nothing would guarantee that the resulting beer would be drinkable. In addition, it could take quite a long time, which did not fit into the time allotted for the celebrations.

A similar situation developed on farms. Grain products used in brewing were very valuable raw materials in those days. If beer were regularly rendered unfit for consumption, it would be quite costly to produce. In the 19th century, Norwegian farmers typically brewed beer 2-3 times a year because they simply didn't have enough grain to brew it more often. During the Viking Age and even earlier, beer was brewed on almost every farm. Clearly, people have somehow managed to brew quality beer on a regular basis.

Thus, it would be logical to assume that the reuse of yeast began long before the 16th century. Can we prove it? Actually, yes.

One of the earliest "recipes", often attributed to Zosimas of Panopolitan, was not actually written by him. Zosimus lived in the 3rd and 4th centuries AD. e., long before the era of printing, so he created his works by hand in the form of manuscripts, which were then repeatedly copied. Approximately in 1000 AD. e. as part of one of these copies, a recipe for beer appeared, which was not in the original manuscript.

The recipe clearly states: "Crush the remainder and make [from the resulting mass] a cake, adding yeast to it as for bread." The text of the recipe is in Greek and uses the word ζύμη for yeast. In modern Greek, it means "yeast", and such terms as "zymology" (the science of fermentation) and "fermentation technology" come from it. It should be borne in mind, however, that we are talking about an ancient text. So can we be sure that the word in question meant "yeast" at the time the recipe was written? Here is what Max Nelson, professor and specialist in the history of ancient Rome, says about this in his doctoral dissertation on beer in ancient civilizations: “In ancient Greek, the term ζύμη was used for yeast, and its Latin counterpart was the word fermentum.” Therefore, we are correct in our reasoning.

There are other sources that support our idea. In the 77th century A.D. e. Pliny the Elder wrote that the Iberians (Spain) and Gauls (France) used the yeast foam obtained during the fermentation of beer to bake bread, which made it lighter and tastier. It is hard to believe that these peoples, resorting to such a method, did not realize the obvious fact that it works equally effectively for brewing beer.

Max Nelson's dissertation is essentially a collection of quotes about beer taken from ancient Greek and Roman sources, presented in thematic order. So, under the heading "Yeast" the following text is given:

“In one financial document of an ancient brewer, compiled in the first century A.D. e. on a papyrus from Tebtounis, mention is made of "jugs of yeast" […], indicating the use of a fermented liquid for the fermentation of beer. On ancient Greek and ancient Egyptian papyri dating from the first and second centuries A.D. e., the profession of "yeast" (zymonrgos) is mentioned. This cumulative evidence indicates that already in the first century AD. e. there were specialists in growing and cultivating yeast for the production of bread and beer.” Thus, the results of the study of documentary sources are fully consistent with our assumptions.

There is no indication that the re-use of yeast began in the first century CE. e. Nelson cites ancient Egyptian writings, while Pliny the Elder spoke of the peoples who inhabited modern Spain and France. It is logical to assume that by this time the use of yeast was already an established practice over a fairly large area. It is possible that their reuse originated around the same period as brewing itself, but to date there is no evidence for this.

Delwen Samuel examined the dry residue obtained after the fermentation of beer, which was found in Amarna (Egypt) and dates from the period from 1080 to 1550 BC. e. Studying the studied material under an electron microscope, she found clusters of yeast cells in it, which most likely belonged to a strain of Saccharomyces cerevisiae. However, this circumstance does not in any way prove the fact that the yeast was used intentionally, because even spontaneous fermentation most often occurs in the presence of these yeast cultures. Thus, to determine exactly when the yeast began to be reused is not an easy task, which has yet to be solved.

At the end of fermentation, when the yeast has eaten all the sugar and its internal reserves, they settle to the bottom, since carbon dioxide is no longer emitted by them and it does not mix the mash, keeping the yeast afloat.

At the bottom of the fermentation tank, both live and obsolete yeast are in the sediment.

Live yeast can be reused for fermentation.

You can add warm water, sugar and fresh yeast to the yeast sediment.

We do not know how much live yeast is left in the sediment, but I usually add half the usual amount to the sediment.

If you add a full dose of yeast to the mash along with the sediment, then the mash will ripen faster.

If you use the sediment and the full rate of yeast, then you can make the hydromodule not 1:5, but 1:4.5, thereby increasing the alcohol content of the mash by a degree.

The resulting larger amount of yeast will push through, accelerate the last, slow segment of the maturation of the mash, and it will be ready as if the ratio of sugar and water is 1:5.

Yeast sediment is desirable to be without flour top dressing. There is a possibility that lactic acid bacteria will start up in the sediment from top dressing and the future mash will turn sour.

The previous mash should be without top dressing or with top dressing for yeast from old jam or from old berries, citrus peels.

It is also not advisable to use the yeast sediment many times, for the same reason, the colonization of lactic acid bacteria or even putrefactive bacteria in it over time, because dead yeast is protein, food for them.

How to store the sediment of ripe mash so that it does not deteriorate, does not lose its strength.

Ideally, as soon as the mash is ripe and the yeast has settled to the bottom, the mash will clear up. We immediately prepare a new one, on the lees, with the addition of new yeast.

If we do not have time for distillation and there is no container to pour the mash for storage without sediment, then the mash must be taken out into the cold, into the frost.

At a temperature of 0 to 4 degrees, the yeast goes into hibernation, suspended animation, and stops eating.

If the storage temperature of the mash or yeast sediment is higher, for example 5 degrees, the yeast will wake up and require food. The higher the storage temperature, the more active the yeast and the more food they need.

Yeast without food will die.

The way out is to add a little sugar to the yeast sediment stored in the refrigerator.

If the mash will not wait long in the wings for the distillation, then you can add a little sugar to it.

If the mash will stand for a long time before the distillation, then you can pour 4 liters and add 4 liters of water and 1 kilogram of sugar with a new one. Yeast will begin to feed on a new one.

If the mash is cloudy and not sweet, then the yeast is still eating its internal reserves, you can not add sugar, but it is advisable to take it out to the cold.

The container for storing yeast sediment in the refrigerator must be closed so as not to introduce foreign bacteria into it.

In order for the yeast to also multiply when stored in the refrigerator, if the temperature there is above 4 degrees, then it is desirable to saturate the yeast sediment with oxygen, it is necessary to mix it strongly.

In this case, dead yeast will be a building material, and the added sugar will be energy for the living.

At enterprises, when preparing mash or beer, the bottom of the fermentation tanks is shaped like a cone, at the end of which there is a tap. Dead yeast accumulates at the bottom of the cone and can be drained first, separating the live yeast from the dead.

At the very top of the sediment there will be fighting, breeding yeast, adapted to a high concentration of alcohol. By selecting them, you can bring out your own type of yeast.

Smart economy is one of the traits of homebrewers who appreciate every penny invested in making a great foamy drink. Not many people know the technology that allows yeast to be used twice due to the correct rinsing. The process is not very complicated, so it is worth adding its description to the treasury of the experience of an experienced brewer.

Why flush?

When preparing beer, both yeast and grains with hops settle in the fermenter. The task of washing is to separate live yeast, which contributes to significant savings, because malt and hops are not cheap ingredients included in the list of components necessary for a foamy drink. In addition, grown healthy yeast mass is perfect for making sourdough.

Caring owners!
A washed yeast culture is about 6 extra batches of hoppy brew! Once purchased, the product can be used for about a month - amazing economy!

What is needed for flushing?

Enough to stock up:

• two banks, previously sterilized;
• a small amount of boiled or distilled water;
• foil or film with which it will be possible to close the jars.

Attention!
It is imperative to sterilize or disinfect prepared devices: any infection is detrimental to the yeast mass.

What is the flushing algorithm?

The technology itself is not at all complicated, does not take much time and does not require lengthy preparations.

1. First, the jars are sterilized with steam of boiling water or a special safe disinfectant, for example, iodophor, which is also used to wipe the sides of the fermenter.
2. Then boil up to 3 liters of water in a saucepan and cool.
3. The most active yeast mass is in the primary fermenter, so it is most suitable for washing. After pouring the beer from the fermenter, it is necessary to collect the yeast immediately to prevent contamination. The sludge at the bottom of the fermenter should be diluted with 1 liter of chilled boiled water so that you can work with the mass.
4. After the water is added, the container must be shaken, which will break the bonds in the sludge, and leave for a while to settle.
5. Carefully pour the settled liquid into a jar, keeping the surface sterile, close with foil or plastic wrap, securing with an elastic band for reliability.
6. Put the jar in a cold place (you can in the refrigerator) for about an hour or a little less. During this time, there will be a clear separation into sediment and liquid, which will contain live yeast.
7. The liquid with yeast in suspension must be drained, trying not to shake the sediment, into a clean jar, cover it and put it back in the refrigerator for about 1 hour.

Advice!
If there is a lot of sediment in the second jar, then by adding water, you can rinse the yeast culture again. However, this is often not required.

How to store the resulting mass?

The storage of the washed yeast can last for several months, and the use of the mass for making beer is as needed.

In the case of long-term storage, the best container option would be not a jar, but a bottle or flask with an adapted water seal. Storage should be in the refrigerator regardless of the dishes chosen.

How to use bottled yeast?

Having estimated the approximate volume of beer that will be brewed, the day before, the wort is added to the yeast in the required amount.

If you intend to brew the beer several more times, then it is enough to use only a part of the stored starter, or you can repeat the algorithm for collecting the live yeast mixture from the original fermenter.

Important advice!
The use of the described technology is limited to the use of the same yeast up to 5-6 times, so as not to increase the risk of infection of the culture with various bacteria or wild yeasts.

Enjoy delicious home-made beer, delight your loved ones at the family table or friends in a circle of friends, while not forgetting about thoughtful savings with the help of the presented technology!

Brewing yeast is a type of single-celled fungus that can be used to make a hoppy foamy drink. To date, there are many different strains of these microorganisms. They are divided into two types: some are suitable for making lager, while others are suitable for making ale. Not many today know that it is not at all necessary to throw out the sediment that forms after the preparation of a batch of beer, because it still contains a lot of live yeast. They are the ones that can be reused. Also, not everyone knows that in the manufacture of 20 liters of beer from one package of yeast, weighing 10 grams, under-sowing occurs.

Often manufacturers offer little yeast, and regardless of whether they are dry or liquid, they can be weakened initially. It is for this reason that more experienced brewers strongly recommend fermenting the yeast before adding it to the wort, that is, making a starter.

It is not necessary to do this every time, because for the preparation of the next batch of beer, you can use the yeast that remained at the bottom of the brewery. Each such cycle is called generation, at the end of which you can get a portion of live yeast, which is completely suitable for preparing the next batch of foamy drink. There is also an opinion that after the third generation, the fermentation process in beer will be better. However, this is only an opinion that can be argued with.

It is important to add that in brewing all the equipment must be clean, otherwise the wort can become infected, which will lead to an unpleasant smell and taste of the finished drink. This is also important to remember when preparing yeast for recycling. It is also necessary to avoid drafts and do not forget to replace the water seal with cotton wool soaked in alcohol when preparing yeast.

First you need to boil and cool to room temperature two liters of water. It must be poured into a fermenter barrel and mixed. Let stand for thirty minutes, and then carefully drain the liquid into a two-liter vessel. All strains of yeast can be generated, but it is worth considering that some can settle in ten minutes.

The heavier, dried fractions of protein, hops and yeast will precipitate. From this liquid, it will later be possible to isolate the necessary microorganisms. This will take an hour. Old and dead yeast, as well as hop and protein residues, will settle to the bottom first, and the top 80% of the liquid can be used for re-fermentation. If you wait longer than an hour, then in the vessel you can observe a lighter layer, which is the yeast.

The number of generations can be unlimited if all equipment is thoroughly washed and disinfected. It is impossible not to notice that in industrial breweries yeast can be generated up to 80 times, while the aroma and taste of beer will be preserved. Do not forget that even with minor signs of infection, it is better to get rid of yeast.