Where is the best place to put the wine for fermentation. Rapid fermentation and care. How long should homemade wine ferment

Yeast consists of oblong cells with a cross section of approximately 0.006 mm. In the form of microscopic cells, yeasts are ubiquitous in the air. Their presence is a necessary condition for the fermentation of the must. If the wort is passed through filter paper and thus the yeast is isolated from it, then fermentation will stop and will not resume until, in one way or another, the yeast fungi enter the wort.

The more the wort comes into contact with air during mixing or pouring, the more fungi it absorbs and the stronger the process of fermentation and yeast development.

Yeast fungi are not afraid of either light or the influence of sunlight, as long as the temperature does not exceed 48 ° C. Yeast has the following chemical composition: nitrogenous substances - 62.73; fiber - 29.47; fatty substances - 2.10; minerals - 5.80.

At different temperatures, yeast has a different degree of reproduction.

The lowest temperature at which yeast fungi retain their vital activity has not yet been precisely determined. But there are researchers who believe that yeast can retain the ability to initiate fermentation even at temperatures below 0 ° C.

The highest temperature at which the yeast retains the ability to excite the fermentation of the wort is defined differently by different researchers. Some of them believe that only by heating the wort to 70 ° C can completely destroy all fermentation germs. Wine requires a lower temperature for this.

During the fermentation process, a bucket of wort releases about 300 g of raw yeast, which gives approximately 46% dry matter.

Yeast fungi, like any other plants, need food. It is nitrous acid and the substances that make up the ash. In particular, it is potassium and phosphoric acid. In every plant juice, and therefore in grape juice, all nutrients are found in greater or lesser quantities. Therefore, the wort begins to ferment when yeast fungi enter it. The development of fungi can continue only until the substances that feed the fungi are depleted or compounds are formed that inhibit, and then completely stop the development of fungi.

Under the influence of yeast fungi, various changes occur in the wort: the surface of the wort takes on a more or less brown color, bubbles appear from the developing carbonic acid, the husk rises up, forming a hat. The sweetness gradually disappears, and the wine taste develops more and more. New substances appear in the must, such as glycerin, succinic acid, etc. This whole process is called must fermentation. One of the main changes that take place in the must during fermentation is the conversion of sugar into alcohol and carbonic acid, with the formation of glycerol and some other substances, but in a relatively smaller amount. A certain amount of yeast can only break down a certain amount of sugar. If there is less yeast than necessary to decompose the entire amount of sugar in the wort, or there are not enough nutrients for their further development, then fermentation proceeds slowly at first, and then stops altogether without decomposing the entire amount of sugar. As a result, the sweet taste is retained. This happens with wort containing too much sugar. The best and most beneficial ratio of sugar to water is 1:4 (1 part is sugar). Natural juice is rarely deficient in yeast or nutrients. But in juice diluted with water with added sugar, this part increases.

Along with yeast fungi, other fungi develop in the wort that give rise to mucus, mold, acetic and lactic acids, as well as various kinds of diseases. To give priority to yeast fungi and slow down the development of harmful microorganisms as much as possible, we recommend that you do the following. During the general grape harvest, the best healthy and most ripe grapes should be collected in a separate container. Then squeeze the juice out of them and let it ferment. In the future, this fermented wort is placed in the made later. From the addition of fermenting wort, proper alcoholic fermentation is immediately initiated.

Influence of temperature on the course of wort fermentation

At a temperature of 4 ° C, fermentation almost stops, but intensifies as it rises. Upon reaching 30 °C, fermentation begins to slow down, and at 40 °C it does not occur at all.

Fermentation at a temperature of 25-30 ° C exposes the wine to dangerous diseases, since this temperature is favorable for the development of lactic, butyric and other acids.

In addition, it turned out that up to a temperature of 27 ºC, fermentation constantly accelerates, and then gradually slows down.

As for the development of the bouquet, the temperature of 15-20 ° C is the most favorable.

Effect of air on fermentation

Yeast fungi for their development and reproduction require exposure to air. Therefore, with a weak access of air, the wort ferments incomparably more slowly than with a free or increased flow.

Effect of filtration on fermentation

Filtration greatly slows down the fermentation process. On this basis, rapid filtration can stop the fermentation process, to ensure that the wine remains sweet.

The effect of alcohol on the fermentation process

During fermentation, some of the sugar is converted into alcohol. But you need to keep in mind that alcohol kills yeast. Thus, in the fermentation itself lies the reason for its cessation. If by fermentation or in another way, for example, by simply adding alcohol, it is formed by volume up to 18%, then fermentation will completely stop. The lower the temperature, the lower the percentage of alcohol stops fermentation.

The influence of dishes on fermentation

The wort ferments much faster in a large vessel than in a small one.

Maturation of the wort to induce fermentation in it

Cold wort ferments very slowly. Therefore, if the temperature of the wort is below 15 °C, artificial heating should be resorted to. When heating the wort, it must be borne in mind that its temperature rises significantly from fermentation. If you want the must to ferment (20–24 °C), then you should heat it to a temperature of 16–18 °C. A further increase in temperature will be achieved during the fermentation process itself.
Wort can be heated in a variety of ways.

First way. You can increase the temperature in the room where the wort is delivered. This is the best way, but it has its downsides. If we have a little wort, then because of it it is not necessary to heat the room. It also happens that there is no specific room where it would be possible to bring the temperature to the desired level. Therefore, we propose another way of heating the wort.

Second way. It is enough to heat a separate part of the wort to such a temperature that, when mixed with the rest, the entire mass is brought to the desired temperature. You can heat the wort directly in an enameled or other vessel. This method presents some inconvenience, since the taste of boiled must appears, which then turns into wine. As a result, not the wort itself is heated, but water and the vessel with the wort is kept in it until it reaches the desired temperature.

How to slow down fermentation

It is known that fermentation slows down at low temperatures, but increases as it rises. Therefore, to slow down the fermentation, they resort to cooling the wort. This is done in the same way as warming the wort, but with the only difference that instead of hot water, cold water is passed through.

How to stop fermentation

The fermentation of the wort can be stopped by introducing sulfurous acid into it. To do this, an empty barrel is smoked in the usual way, then about three buckets of wine are poured into it, the entire barrel is rinsed with it, and then it is again smoked with sulfur. Then 3-4 buckets are poured again and so on until the entire barrel is filled.

The fermentation of the wort stops if:
1) the wort is heated to a temperature of 40 °C and above;
2) the alcohol content in the wort is adjusted to 18% or more;
3) all yeasts are removed by filtration.

Carbon monoxide (carbonic acid)

Wine fermentation, especially vigorous fermentation, releases carbonic acid, known as carbon monoxide. This gas is extremely harmful. A person, inhaling it, faints, and then, if medical assistance is not provided in time, death may occur.

To prevent such accidents, the following precautions must be taken when visiting a cellar in which young wine is fermented:

1. It is desirable to visit the premises together.
2. Going into the room, you need to take a candle with you. If it burns normally, then you can go in. If it goes out, this is a signal that it is dangerous to enter the room, since there is a large accumulation of carbonic acid.

Carbonic acid is 1.5 times heavier than air, therefore, it accumulates and stays mainly at the bottom and rises only as it accumulates. Therefore, the candle must be kept low, but not bent over.

To remove the accumulated carbonic acid, it is necessary to open all the doors and openings that are in the room. At the same time, a vessel is placed inside, into which pieces of quicklime are thrown.

If, nevertheless, carbon monoxide poisoning has occurred, then the victim must be taken out to fresh air and doused with cold water.

Sugar

Only the smallest traces of sugar remain in the finished wine, only liqueur wines, either made from dried grapes, or to which alcohol has been added during fermentation, or the fermentation of the must has otherwise been delayed, contains a large amount of sugar. If in ordinary weak wines the sugar content reaches 0.1–0.2%, then sweetness is already felt. Some wines retain a small amount of sugar for quite a long time, so the presence of sugar in wine does not yet prove artificial addition.

Alcohol

Alcohol is one of the main parts of wine. Its content is essential for its character and transparency. 100 parts by weight of sugar in must produce 48.4 parts of alcohol in wine. Practitioners know that every percent of sugar in the must yields 0.5% of the alcohol in the wine. The highest alcohol content that can be developed by the fermentation of wine juice is 18%. Higher content is an artificial impurity. The alcohol content in wine decreases over the years: wine loses 0.25-0.5% alcohol per year.

Coloring matter of colored grapes

The coloring matter of colored grapes is slightly soluble in water. A little more soluble in water with acid, and best of all - in a mixture of dilute alcohol with a small amount of acid. The color of the wine is enhanced during pouring, release:

a) from the husks of overripe berries;
b) from too high a temperature;
c) from any finely ground powder, especially containing protein substances;
d) from prolonged exposure to air and light.

The amount of dye depends solely on the grape variety.

Extractive substances make up the sediment obtained after the evaporation of wine. They are, so to speak, the body of the wine, which determines the taste and thickness of the drink. The content of the extractive substance is 1.4–3.0%. In sweet wines it is incomparably more.
The mineral composition of the wine has little effect on its taste.

The tannin is taken by the wine during the fermentation of the must and a little while pressing from the husks, grains and scallops. It does not exist in pure grapes.

In contact with

So, we pressed the pulp of red grapes or removed the fermenting white must from the coarse sediment, and received wine material, your future homemade wine, containing about 1/3 of the initial sugar content. Someone calls it young wine, but I believe that the must becomes it after the end of the stage of quiet fermentation.

Vessels for silent fermentation

Where does secondary fermentation take place at home? Most often these are 10 or 20 liter glass bottles or 19 liter plastic drinking water bottles. Some winemakers use barrels or other vessels. The main requirement for them: they must either be filled almost to capacity, or have a floating lid, which allows you to minimize the air gap between the wine and the shutter, since at this stage contact with air is already undesirable for the must.

I recommend using transparent vessels: they clearly show the layer of sediment that has formed and dead yeast, which greatly facilitates subsequent transfers. See for yourself: after the wine has been fermenting in the bottle for a month, you decide to decant or pour it, without touching the sediment, into a clean bottle. You can clearly see the layer of sediment at the bottom and take care not to accidentally touch it during the transfusion process. In an opaque container, this will be much more difficult. It is necessary to arrange a drain valve at a certain height above the bottom, or somehow still contrive when pouring.

Taste the wort - just to see how it tastes. The taste will be terrible, I guarantee it. 🙂 Even later great wines at this stage are “she ta gidota” - the must is saturated with yeast, alive and dead, full of all sorts of fresh volatile components formed during the fermentation process, possibly “seasoned” with all the delights of the flavors and aromas of YaMB. But still, the winemaker must know and understand the tastes of must and wine at all stages of its creation. Young wine is like a child, clumsy and unsympathetic at the very beginning, but then developing into a beautiful creation.

Using Air Blockers

A cylinder with a capacity of 19 liters is familiar to everyone. I use exactly those. I am sure that in a couple of months the wine will not pick up any harmful components from food plastic. It is also important that they are much easier to work with than glass 20-liter bottles due to the large dead weight of glass bottles and the danger of breaking them. So, if you have a friend who bottles drinking water, it's time to take advantage of your friendship. I don’t have such a friend, and I negotiated with the courier of the company that brought water to our office. You can always buy a small number of such cylinders "at a reduced price" from them.
Since from now on it is very important to keep air out of the wort, the neck of the bottle is plugged with a cork in which a hole is drilled. An air blocker or shutter is inserted into this hole, allowing carbon dioxide and other gases produced during fermentation to freely exit the bottle with future homemade wine, and does not allow air from outside to enter the bottle. There are many types of air blockers. The most common ones are shown in the figures below:

My favorite type (for aesthetic reasons) is the single glass bollard. But, since this model is not the cheapest and rather fragile, I use a single plastic blocker more.
Top up the can up to the “shoulders”, i.e. to the point where the can begins to taper into the neck to leave enough room for the foam. Never allow foam to rise to the level of the bollard or get inside. Foam can overflow through the bollard onto the floor, which will immediately attract swarms of insects and, of course, cause mold to thrive. If the wine does not release gas through the choke, clean and replace the choke and pour some of the wine out of the bottle.

Quiet fermentation should take place in a room with a relatively low temperature - from 16 to 21 ° C. Try to keep the bottle of fermenting wort as far as possible from the direct action of cold, drafts. At this time of the year, as a rule, it is already deep autumn.

When the silent fermentation is complete, the empty space in the can creates a small vacuum that pulls the disinfectant solution towards the can. This is the signal for the end of fermentation. Don't let the air blocker work the other way around, drawing air (and solution drops) back into the wine. To prevent this, you should carefully monitor the progress of the secondary fermentation. After some time - this may take from a few days to a month or two - the number of bubbles will decrease from many per minute to a few per day. A few days after that, when the formation of gas bubbles stops altogether, strain the wine - yes, yes, this is already a young wine! - with a hose (this process is also called “removal from the sediment” or “decantation”) into a clean bottle and cork it with an air blocker, which must first be thoroughly rinsed and filled with fresh pyrosulfite solution. This time, the wine should be poured into a bottle, a couple of centimeters short of the bottom edge of the cork. Thus, only a minimum volume of air will remain in the cylinder. Some gases dissolved in the wine will come out, the air blocker will release some bubbles. Then everything will calm down, and it will be possible to put the wine on aging.

Many winemakers use medical gloves with pierced fingers to release gases instead of a blocker. You can, of course, do it that way, but I don’t like it: it’s impossible to accurately follow the stages of the fermentation process, and it’s unaesthetic. Buying blockers today is not a problem. But if you still can’t find it, do this: insert a flexible tube (for example, from a medical dropper) into the cork of the bottle and lower its end into a glass of water. The glass can be placed next to the bottle, or you can tape it to it: it will be more convenient to move it.

First skimming

You need to sulfite your homemade wine a little during the first decantation after fermentation, since the sulfur we added when crushing the grapes has already partially bound in chemical reactions, and partially evaporated with carbon dioxide during fermentation. Some winemakers add large amounts of sulfite to the wine at the first decantation. Some don't add at all. If you have added the minimum amount that I recommended in previous articles, you can add more
25 mg of sulfur per liter, this is approximately 1 g of pyrosulfite per bottle of 19 ... 20 liters. This makes the wine more transparent and preserves it, especially those wines that are sent to the cellar for storage and aging.

Since the duration of the period of secondary fermentation and settling of a clearly distinguishable layer of sediment can vary from one to ten weeks, it is difficult to formulate any clear time frame for the first decantation. Suffice it to say that the first pumping should be done when all the sugar has fermented into alcohol and gas formation has completely stopped. Almost always, with rare exceptions, this happens already at the end of November-December.
After the first decantation, the amount of wine will decrease by the amount of sediment you separate. I have found that, as a rule, three bottles of unstrained wine, filled to the "shoulders", make two full bottles of finished wine. If you need more wine to top up the bottle, use the same variety, store bought or good homemade. The wine for topping up should be no worse in quality than the wine you are topping up! For decanting wine, you need to have spare bottles on hand. You only need one spare bottle if you immediately wash the first bottle you just emptied and use it to drain the second bottle. A couple of spare bottles are always very handy, and I can afford to wash the used bottles when I have free time, at the end of the whole process, rather than tossing around during the desludge process.

It often happens that when you fill a bottle, there will be too little wine left to fill a whole bottle with it. This is where 6 liter bottles, in which mineral water is sold, come in handy. Also keep a few 2- and 1.5-liter mineral water bottles on the farm. The wine must be poured under the lids without residue. What else are mineral water bottles good for - if 200 ... 300 ml of wine is not enough to fill it under the neck, you can simply squeeze it, releasing excess air, and twist it. It is good to use such small vessels for topping up larger containers: bottles or kegs, which we will talk about when aging wine. In no case should you leave a container with fully fermented wine not completely topped up, otherwise the wine will deteriorate.

On this, on the first sludge removal, we finished with the fermentation process, the formation of our young house wine from the grape must. Now he has to move from the stage of childhood and youth to the stage of maturity - to go through the process of endurance. We will talk about it in the next article. In the meantime, you already have enough information to meet the beginning of the winemaking season! 🙂

Grape wine is the oldest drink created by centuries of labor and skill of peoples inhabiting vast areas of temperate and hot climate. From the simplest domestic processing of wild-growing and "domesticated" grapes, wine production has come a long way in development and improvement. Many wines with established high quality and established names are known in the world wine trade and occupy a large place in the export of wine-producing countries. Along with this, a colossal amount of wine is produced for household use and for sale within its wine-growing region.

FERMENTATION

It is enough to crush the grapes in a vessel for spontaneous heating of the resulting mass, leading to the gradual disappearance of the sweet taste. This process is called alcoholic fermentation (alcoholic fermentation), thanks to which grape juice, in fact, turns into wine.

A microscopic fungus of the species Saccharomyces cerevisiae - yeast - develops in the must. As a rule, the yeast that is found on the skin of the berries is enough for fermentation, but other specially grown cultures have been increasingly used recently. Unfortunately, their use often leads to the fact that the aromas of different wines become remarkably similar.

Yeast feeds on sugar and converts it into ethyl alcohol and carbon dioxide. By-products of their vital activity are also glycerol, acids, higher alcohols and esters, which even in small concentrations take part in the formation of the aroma of the future wine. Alcoholic fermentation proceeds with the release of thermal energy. Therefore, the vats heat up, which makes controlling their temperature absolutely necessary. Sometimes it is necessary to apply cooling so that the temperature of the must does not go beyond certain limits (20 ° C for white wines, 25-30 ° C for red wines), otherwise this can adversely affect the quality of the wine. In some cases, in addition to alcoholic fermentation, after it, malolactic fermentation is also used. This process was introduced to improve the quality of red wines only in the 60s. With regard to white wines, the benefits of it are not so obvious.

It is produced by lactic acid bacteria, the same bacteria that cause milk to go sour. They decompose malic acid into lactic and carbon dioxide, at the same time "grabbing" other organic compounds. If such a process occurs spontaneously and is not planned by the winemaker, then it can lead to damage to the wine material. There are preparations from cultural strains of lactic acid bacteria. They are used to improve the taste of highly acidic wines. But to start such a biological acid reduction, first it is necessary to carry out a partial deoxidation of the wort with chalk, then add this preparation, raise t to +20 C and stop the process by sulfitation in time. For the processing of highly acidic wort, a special acid-reducing yeast called acidodevoratus, which in Latin means "acid scavengers", is better suited. During normal alcoholic fermentation, they convert malic acid into alcohol and carbon dioxide by-products. As a result of acid reduction, the wine becomes softer, thinner and acquires a complex aroma. This increases the biological stability of the wine, which is very important for its subsequent storage.

Therefore, this type of fermentation is called apple-ethanol . It is used to make dry wines from raw materials with excessive acidity.

In many cases, the production of wine uses the method of chaptalization, named after the French chemist Jean-Antoine Chaptal (1756-1832), who served as Minister of Agriculture of France under Napoleon I. This method consists in adding sugar (grape, beet or sugar) to the must. cane) in order to increase the alcohol strength of wine. In France, its use is permitted subject to a number of preconditions. The added sugar must provide an alcohol content of 2.5-3.5% by volume in Champagne, Alsace, Jura, Savoy and the Loire Valley and no more than 2% in other French vineyards of controlled designations of origin.

In the production of dry wines - sugar must ferment completely. In the production of semi-sweet and semi-dry - partially. The situation becomes a little more complicated in the production of fortified (with the addition of alcohol) and dessert (special technology) wines. It is impossible to achieve high alcohol (14-17%) here by natural fermentation. At 17% alcohol, the wort self-preserves and the yeast dies. Moreover, 14-17% sugar should be present in the wine. Therefore, fermentation is carried out until the necessary sugar remains in the must, and then alcohol is added, bringing its content in the wine material to the required level. That is, fermentation is interrupted by alcoholization. According to the correct technology of fortified wines, natural alcohol should be at least 3% out of 14%.

It is important that the must be protected from exposure to air (usually a layer of carbon dioxide acts as a protective screen), otherwise vinegar will turn out instead of wine. At the same time, air is necessary to maintain the vital activity of the yeast, so the wort is aired from time to time.

Some important information about alcoholic fermentation.

At temperatures below +10 C, fermentation stops. At temperatures from +10 C to +27 C, the fermentation rate increases in direct proportion, that is, the warmer - the faster. From 1 gram of sugar during fermentation, the following is formed: - ethyl alcohol 0.6 ml. or 0.51 gr - carbon dioxide 247 cubic cm or 0.49 gr. - heat dissipated into the atmosphere 0.14 kcal Sugars are actively assimilated by yeast, when the sugar content in the wort is in the range from 3% to 20%. As soon as the concentration of alcohol in the must reaches 18%, then all wine yeasts die. There are some types of cultural yeast that die already at an alcohol content of 14%. These are used to make wines with residual sugar. The carbon dioxide released by the yeast cells in the wort slows them down. A bubble of gas, while it is small, "sticks" to the wall of the yeast cell and prevents the flow of nutrients to it. This situation continues until the cell "inflates" this same bubble to a certain size. Then the bubble floats up and drags the yeast cell with it up to the surface of the fermenting liquid. There it bursts, and the cell sinks to the bottom of the fermentation tank. This process is conventionally called "boiling", and is considered a waste of time in the process.

Types of yeast.

Fermentation can be carried out on wild yeast that live in natural conditions on a grape bush, or on cultural yeast bred and selected by man in the laboratory. The choice of yeast depends on the will of the winemaker. Wild yeast and spontaneous fermentation- live on berries of grapes and a grape bush. When grapes are processed into wine, other microflora enters the must along with them. In freshly squeezed grape juice, on average, mold fungi are contained in a share of 75 to 90%, and various types of wine yeast 10-20%. Some of the microorganisms already at the first stage die in the wort due to the high acidity of the juice and sugar content. Some try to compete with wine yeast and begin to multiply, but they soon die as well, so the supply of dissolved oxygen in the must ends. Wine yeast by this time reaches a high concentration (about 2 million cells per cubic cm of wort), they switch to an anaerobic type of sugar processing. And, thus, they get at their disposal the entire volume of the wort as a whole. Further, different types of alcohol wine yeast begin to compete with each other. The main limiting indicator is how much alcohol is in the wort. While it is small, the greatest number is developed in the red juice of Hanseniaspora apiculata (apiculatus or spiky), in the juice of white grapes - Torulopsis bacillaris. After the accumulation of about 4% alcohol, both species die off. From the "carcasses" of dead yeast, nitrogenous substances begin to flow into the wort. After that, active reproduction of yeast of the genus Saccharomyces, mainly of the ellipsoideus species, in Russian - ellipsoid yeast, becomes possible. They carry out both the main fermentation and the second fermentation. The last interesting thing happens, again, after the appearance of nitrogenous substances from dead cells in the wort. With the accumulation of 16% alcohol, ellipsoidal yeasts die. The final fermentation is carried out by alcohol-resistant yeast oviformis (egg-shaped). But they also fall out at 18% alcohol. Now the wine material is practically sterile. Only the oxygen in the air can spoil it. Fermentation with wild yeasts can produce high quality wines with a wide range of flavors and aromas. After all, several types of yeast that replace each other take part in their creation. But there is a significant risk of getting unfermented or low-alcohol wine if the relay race of yeast fungi is interrupted at some stage. Cultural yeast and fermentation on pure cultures- cultural yeast is obtained as the offspring of a single yeast progenitor cell in the conditions of the microbiological industry. Therefore, the wort is populated with only one type of yeast fungus with exactly the same properties. There should not be any other microorganisms in it. In this case, it is possible to choose exactly those yeasts that will give us the product of the desired properties, for example, sherry yeast, champagne yeast, yeast for red wines, sulfite-resistant races, races with a high alcohol yield, heat-resistant, cold-resistant, acid-resistant, and so on. Competition between microflora will be excluded, and the product will most likely turn out exactly the one that the winemaker was counting on. It should be noted that after numerous experiments, the modern wine industry has come to the conclusion that pure yeast cultures can be used to a limited extent, if the raw material has some drawbacks or it is not possible to maintain the correct temperature during the fermentation process.

Fermentation speed.

The best fermentation is slow fermentation. At high temperatures, the yeast so actively process the sugars of grape must that the bubbling bubbles of the resulting carbon dioxide carry aromatic, flavoring substances and even alcohol vapors into the atmosphere. The wine turns out flat, with unexpressed taste qualities, and loses its degree. At temperatures from +25 to +30 there is excessive fermentation. Yeast quickly multiply and quickly die off, nitrogenous substances constantly enter the wine material, which are formed during the decomposition of dead cells, and this increases the risk of turbidity, disease, and overoxidation. At t above +30 ° C, the yeast dies, and sugar (non-ferment) remains in the wort. In such a nutrient medium, foreign bacteria immediately begin to multiply and product spoilage occurs.

stages of fermentation.

The entire fermentation period is conditionally divided into three phases: fermentation, rapid fermentation, quiet fermentation. fermentation- the initial period when the yeast adapts to the conditions in the fermentation tank and begins to multiply; violent fermentation- the period when the yeast multiplied, occupied the entire volume of the wort and switched to an anaerobic mode of nutrition with the release of alcohol and other substances into the surrounding liquid, their number is growing; silent fermentation- the main sugar is converted into alcohol, the number of yeast cells is reduced. This diagram displays stationary fermentation method. It is important here that the container is filled with fermenting wort by no more than 2/3 of the volume. Otherwise, with foam in the middle phase, the contents will be thrown out. This leads to irrational use of fermentation tanks and instability of processes inside it. Fermentation is more stable when top-up fermentation. True, this technology can only be used for the manufacture of dry wines. It is carried out as follows: 1. first, the container is filled with 30% of the total volume with wort and yeast wiring is added to it in full; After 2 days, fermentation will go into the stage of rapid, and the wort will warm up. 2. on the third day, another 30% of prepared fresh wort is added; 3. After another 4 days, another 30% of fresh wort is poured into the tank. The fermentation tank is thus filled almost to the top, and the fermentation process itself occurs without sharp peaks and jerks in the number of yeast and their metabolic products. And this is good for the quality of the future wine.

Fermentation "over four" - supercar.

Proposed by the French winemaker Semichon. The main feature is that before the start of fermentation, alcohol is added to the must or pulp in the amount of 5 volume percent. This amount of alcohol is enough for all unwanted microflora in the wort to die. At the same time, the saccharomyces yeasts necessary for fermentation do not suffer at all, but continue their work in the "cleared field". But the addition of alcohol to the must is prohibited by the laws of most wine-producing countries. Winemakers go around and modify the supercart method: first, dry wine material with an alcohol content of about 10% is obtained using the supercart method, then it is added to the bulk of the must in the proportion required for this method.

Fermentation on the pulp.

It is used in the production of red wines and some fortified white highly extractive (saturated) wines. Here, during fermentation, the task is to obtain not only alcohol, but also to remove coloring, aromatic tannins and other substances from the skin and seeds. Fermentation of pulp is always difficult. After all, it is a heterogeneous, solid and viscous mass. In addition, in order to release the necessary substances from the skin and seeds, a temperature of at least +28, and preferably +30 C is required. But at +36 C, the yeast loses activity, and at +39 C they die. That is, a narrow temperature range from +28 to +32 C remains for fermentation on the pulp. Fermentation on the pulp with a floating cap. It is carried out in vats or open containers . The wort is sulphated according to the calculation. Fill them with a container, make a yeast layout. Stir. After a while, violent fermentation begins. The released carbon dioxide drags all particles (flakes of pulp, skin, pieces of ridges and stalks) to the surface and keeps them afloat there. The pulp is stratified into liquid and a "cap" of the solid fraction, floating on the surface, and most often protruding above it. In order to avoid acetic acid souring and improve the extraction of coloring substances, it is necessary to mix the contents of the container 5-8 times a day for 5 days. As soon as the wort acquires a rich color, it is drained, the pulp is pressed and both liquids are combined and kept until the end of fermentation. This method produces the most beautifully colored and full-bodied wines. Fermentation on the pulp with a submerged cap- in order to reduce the amount of mixing with the "floating cap" method, a simplified "dipped cap" method was invented. The "cap" is heated to a depth of about 30 cm using a grate. The number of stirrings with a submerged hat may be less, but the color of the wine will correspondingly be worse. Both types fermentation on the pulp can also be carried out in closed containers. In this case, a layer of carbon dioxide is formed above the cap, which to some extent resists acetic acid souring and simplifies the process.

WINEMAKING

With the completion of fermentation, human intervention in the process of making wine does not stop. It requires many more operations and vigilant care until the moment when it is bottled and sent for sale. The transparency of clothes can be achieved by storing wine for a long time in a small container, for example, in a barrel and periodically decanting it (using gravity or using a pump) in order to remove the settling particles in a timely manner. During this process, the wine not only gets rid of particles suspended in it, but is also ventilated, enriched with oxygen. In Bordeaux, for example, it is customary to pour red wines 4 times during the first year of their aging and 2-3 more times during the second.

The wine is also decanted after fining. It was first introduced into the practice of winemaking in the XVIII century. This process got its name because it originally used glue extracted from the swim bladders of fish, mainly sturgeon and catfish. Currently, it is used not only for clarification, but also for the stabilization of wine. This method consists in adding organic (fish glue, egg white, gelatin, casein) or inorganic (yellow blood salt) compounds to wine, which, coagulating, envelop not only suspended particles, but also some other components of the wine, which can further lead to deterioration in its quality. So the fining of red wines is necessary to eliminate excess coloring matter, which otherwise precipitates. In cases where coagulation of natural proteins is undesirable, as, for example, when fining white wines, they are deposited on materials that do not interact with wine substances - silica, diatomaceous earth, bentonite, kaolin, asbestos.

The use of modern filters allows you to separate particles of a given size from wine; they can be not only particles of the skin or pulp of berries, but also, for example, yeast cells. During centrifugation, the wine is rotated at high speed in a special drum, so that the impurities contained in it are thrown onto the walls and then removed. However, in France there are many winemakers who claim that fining, centrifugation and filtration deprive wines of some of the aromas, and reds also deprive tannins.

However, to achieve the transparency of wine clothing, it is necessary to ensure its subsequent stability. Since living cells (particles of berries, yeast, bacteria) take part in the process of wine production, its composition is extremely complex. Its various components can enter into chemical reactions with each other. The consequence of processes of this kind are the so-called cash registers - clouding of wine and precipitation. At present, methods are known to prevent troubles of this kind. To prevent the development of microorganisms, it is necessary, in addition to maintaining cleanliness, to fill the containers to the top, and then top them up so that the wine does not come into contact with atmospheric oxygen. The use of an antiseptic such as sulfur dioxide (SO2) also gives good results. It is used at various stages of wine production (disinfection of containers, prevention of malolactic fermentation, etc.) in solid, liquid and gaseous forms. However, an excess of this substance not only adversely affects the taste of wine, but can also cause poor health. Some winemakers pasteurize their wines by briefly heating them to 85°C. This kills the yeast and bacteria in the wine, but it also destroys its aging ability: it stops evolving once bottled.

In some cases, during the production, the products of many vineyards are combined, harvested from different years or obtained from different grape varieties. This operation can be carried out already at the opening of the grapes, but more often it is done after the stabilization of the wine or during its aging. In France, there are usually two varieties of it:

assembly (assemblage) - the combination of different varieties of grapes and / or products of different vineyards of the same vintage and within the same appellation. Assembling is a common procedure in the production of high quality wines. It allows you to improve the quality, while emphasizing the features of the type and style of each of them;

blending (coupage) - a combination of wines from different regions and / or vintages from different years. Some improvement in quality is achieved in this case due to the averaging of the wine, the loss of its individuality. Blending applies only to sparkling (including champagne), table and local wines.

Before bottling, the wine may be aged in wooden barrels. However, the exposure continues in the bottle.

BOTTLING

After the wine is made, it is bottled, with or without pasteurization. The bottles are stacked so that the cork is in the wine.

A minimum volume of air is left in the bottle, since the smaller the volume of air, the less oxidation occurs. To ensure proper storage of wines, they are placed in vinnitsa - special warehouses (cellars). The wine cellar must be dry, away from everything that can mold, rot, deteriorate, as all this affects the taste and aroma of wines, even spilled and corked in bottles.

On the eve of bottling, the bottles are thoroughly washed and turned upside down.

Immediately after pouring wine into a bottle, the cork is lowered into alcohol or cognac with the end that goes into the neck of the bottle, which is why the cork goes into the neck better. The cork is inserted with a special machine. Outside, the neck is covered with a special resin, sealing wax, and, in order to ensure further storage of wines, they put the bottles on their sides so that the cork is in the wine.

BARRICK

It is based on the exchange of substances between the wine and the oak wood of the barrels in which the wine is cultivated. During maturation, the wood releases valuable aromas and tannins into the wine. In addition to the traditional astringency that the wine acquires from oak tannins, white wines tend to also have vanilla-peach aromas. Red wines - cherry. Some champagne wines are also made in oak barrels (varieties Bollinger, Roederer, Krug). Oak barrels are not suitable for all types of wines. If strong varieties such as Cabernet Sauvignon or Chardonnay are matched and complemented, then they suppress such fine wines as Riesling.

Already after the first filling, the wood gives up most of its substances, so good winemakers replace barrels after two or three cycles. There are exceptions: Louis Roederer's wine house pours high-quality wines into large barrels (fr. foudres) with a volume of 4.000-5.000 liters, where they mature and are stored for up to 60 years. Wine House Krug produces a typical barrique wine in slightly smaller standard 205 liter barrels traditionally used for champagne.

Some winemakers, instead of the classical technology, pour young wine into metal containers and then “bring” it to a barrique-consistency by additional artificial “tanning”, adding oak chips to the wine - “chips”. Chips soaked in wine sink to the bottom of the container and release their aroma there. However, steel barrels, unlike wooden ones, do not "breathe", and therefore the proper bouquet (a mixture of wine and woody aroma) is not obtained to some extent. Many winemakers, gourmets and professional tasters do not recognize this winemaking technology.

Wines brewed in barrique barrels have worldwide associations of lovers, chains of specialty stores and trademarks.

Until October 2006, the technology of wine with the addition of chips was prohibited in the European Union. After the conclusion of inter-European trade agreements on wine in October 2006, the ban was lifted. However, artificial flavors remain prohibited. Technology with the help of "chips" is not subject to mandatory declaration. However, the producer of such wine does not have the right to indicate on the bottle label that the wine is “produced in an oak barrel” or “matured in an oak barrel” or “contained in an oak barrel.

Length of wine aging

The development of bottled wine is often compared to the life cycle of a person: it gradually matures, reaches maturity, after which it inevitably begins to age and eventually die. At the same time, most of its components precipitate, while it itself becomes lean and sour. The stages of maturation and aging continue for a long time and include barrel and bottle aging of wines. The opinions of winemakers about the life span of wine and the optimal aging time, subject to the conditions for storing wines, are contradictory. Which is quite natural, since grapes come to winemaking of different varieties and qualities, the process of making wine takes place in different ways.

But the wine reaches its highest qualities by the age of 12-16, and after 20 years it begins to fade and by 45 it degrades. Table wines have the best life time - 10-20 years, and after 25 they begin to deteriorate. At the same time, strong wines (Madeira, Tokay) develop up to 50-60 years. Sherry lives over 160 years.

During aging, the wine undergoes complex and diverse changes, not all the reasons for which are known to modern science. It is clear, however, that oxidation plays an important role among them: dissolved air is contained even in wine placed in a hermetically sealed vessel. The most obvious of the changes relate to the color of the clothing. They are especially striking in red wines: the characteristic bright red color of young wines acquires yellow hues as they age, approaching the color of brick or tile. When describing the appearance of red wines after several years of aging, tasters often refer to them as brick red or tile red. In very old wines, the red hue disappears completely, with yellows and browns becoming predominant colors. White wines, on the other hand, darken. It is interesting that in very old wines - both white and red - the color of the clothes is approximately the same. During aging, the aromas of the wine develop: the so-called primary, which it owes to the grapes, and the secondary, acquired during aging (they are dominated by fruit and floral tones), are replaced by tertiary ones (mainly animals). A bouquet appears, the presence of which is a distinctive feature of the old wine. The aggressiveness of the wine is smoothed out, its tannins are made less sharp. The wine becomes more rounded, velvety, soft.

The question of the maximum duration of "life" can only be raised in relation to a particular wine. Some wines are best drunk within six months, while others “live” for decades. Light wines with a low alcohol content do not keep as well as well-structured, full-bodied and strong wines. Not surprisingly, natural sweet and “yellow” wines can age longer than others. As for the duration of storage of dry wines, it is determined by a number of points, among which we can highlight:

Grape varieties from which the wine is made

Age of the vines Older, lower yielding vines tend to produce more concentrated wine.

Soils on which grapes are grown It is known that good wine cannot be obtained on fertile soils. On the contrary, on nutrient-poor, well-drained soils, the vines suffer and, if yields are limited, produce full-bodied, well-kept wines;

Weather conditions during the growing season - what is usually referred to by the term "millesime" (millesime) Too cold summers, lack of sunlight will not allow the grapes to reach the necessary maturity, and rain during harvest will make the wine watery. In both cases, the wine will not be suitable for long exposure. If the duration of storage of wine produced in a bad year is taken as 1, then the corresponding figure for medium and great vintages will be approximately 2 and 4;

Features of the process of vinification and work with wine For example, the refusal to separate the ridges, the long insistence of the must on the pulp, the fermentation in oak barrels increase the tannins of the wine, and hence its durability;

Storage temperature With its increase, the exposure time decreases;

The capacity of the vessel in which the wine is stored The smaller the volume of the bottle, the more actively all reactions take place in it and, consequently, the wine ages.

Silent fermentation and care

The poured wine is not yet completely transparent. It contains some more yeast and negligible amounts of sugar that did not decompose during rapid fermentation. In addition, from contact with air during pouring, the protein substances dissolved in it begin to fall out of the wine until then, which should be removed from the wine, otherwise it may subsequently become cloudy forever and be fragile. All this happens during a quiet fermentation, also called the post-fermentation of wine. Fermentation usually ends after 7–10 weeks. In some cases, it lasts 3-4 months and usually ends by the spring of the year following the preparation of the wine.

Its ending is determined by taste. Fermented wine begins to lighten, sediment forms at the bottom of the bottle. 8–10 days after the end of fermentation, the clarified part is poured into a clean bottle with a hose, filled to the neck, and placed in a cool place.

After about a month, the wine is again removed from the sediment, filtered. You can add sugar to taste (from 2/3 to 3/4 cup per 1 liter of wine). When it dissolves, the volume of wine increases, so the concentration of alcohol decreases accordingly from 15–16 to 13–14% of turnovers. The need to open the bottle during the fermentation process to remove foam, remove excess juice, add juice or sugar should not embarrass the winemaker.

In appearance, quiet fermentation is manifested only by the fact that at first (1–2 months) bubbles of carbon dioxide are occasionally released - one every 5–10 minutes or more. Gradually, the release of gas decreases more and more and, finally, stops altogether. At the same time, a thin brown layer of sediment settles at the bottom of the dish, the wine becomes more and more transparent, its rough taste is replaced by a pleasant one, and a bouquet begins to develop in it.

The care of the wine during this fermentation consists mainly in monitoring the temperature and frequent pouring of the wine.

The temperature of the room in which the wine is placed for such fermentation should be even, without sharp fluctuations, and keep around 10-12 ° C. With home winemaking, of course, one does not have to be too demanding in this regard and be content with what is available on the farm. So, for example, you can put wine for fermentation in an unheated room, in a dry underground, in a dry cellar or cellar, if it is not too cold in them and there is no danger that the wine will freeze. In a very cold (but not freezing) cellar, the wine will keep well, only its maturation will last longer than it would if the temperature were at the specified norms. For fermentation of wine, in extreme cases, you can use the refrigerator.

Since in most cases of home winemaking there is a shortage of an appropriate room, it is therefore more profitable to make wines stronger or sweeter, which are more durable and enduring at inappropriate temperatures, using the home method. Of course, clean air is needed in the room where the wine is fermented, and neither sauerkraut nor other strongly or unpleasantly smelling products should be stored, because the wine from them will acquire an unpleasant smell and spoil.

Transfers of wine during maturation are carried out with a dual purpose:

1) to clean the wine from sediment settling on the bottom of the dish, which could give the wine bitterness, and 2) to ventilate the wine.

The latter is very important, because it accelerates the precipitation of substances dissolved in wine that can subsequently cloud the wine. Therefore, the more often the wine is poured and aired, the more it is purified and becomes transparent. If the wine is kept in glassware, then transfusions and airing should be done after 1 month and even more often, because the more transfusions are made, the more fully the wine will ripen and the more completely all the substances that disturb it will fall out of it. They try to make transfusions so that the wine flows in a thin, long, strongly splashing stream, for better ventilation; the wine drained during transfusions is poured into cleanly washed dishes, if possible up to the cork itself.

If dessert or liqueur wine is being prepared, then, at the end of quiet fermentation, it is sweetened.

The filtered wine is bottled and sealed. Store in a dark place at a temperature of 10-20 ° C in a standing or lying position.