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People involved in home winemaking sometimes encounter this problem when the fermentation of the wine must suddenly stops. In this case, it is quite difficult to determine why fermentation stopped, because such an incident can happen even if all the technology for preparing homemade wine is followed. A This problem is quite serious, because it can lead to damage to the entire wine material, which means that the winemaker’s work will go down the drain and the products can be thrown away.
To decide what to do in such a situation, you first need to find out why the wine stopped fermenting in a particular case. What factors can cause the fermentation of homemade wine to stop, and how this process can be resumed - this will be the subject of the article.
Features of the fermentation process
The technology for preparing homemade wine can be different, and various products can be used in winemaking: fruits, berries, grapes. But anyway homemade wine must undergo a fermentation process, otherwise the juice of fruits and berries will not turn into a wine drink.
Wine or yeast fungi are responsible for the fermentation of fruit juice. Typically, such fungi are found on the peel of fruits and berries, and appear as a whitish or grayish coating.
These fungi feed on sugar; in the process of their life, they process sugar, turning it into alcohol - this makes the juice an alcoholic drink. In addition to alcohol, carbon dioxide is produced during the fermentation process, which is what inflates the gloves on bottles of wine or comes out in the form of air bubbles from under the water seal.
Natural sugars are found in almost all fruits or berries; only their quantity can vary. Those products that are suitable for winemaking are those that have a fairly high content of natural sugar in the form of glucose, sucrose and fructose.
The sugar content of fruits and berries may depend on factors such as:
- crop variety;
- ripeness of fruits or grapes;
- fruit picking time;
- the aging time of fruits in the interval between harvesting and laying wine.
To prepare high-quality homemade wine, it is recommended to collect only fully ripened fruits and berries, to do this within the prescribed time frame, to prefer varieties that are characterized by high sugar content of the fruit (the taste of the fruit should be more sweet than sour).
The insufficient natural sugar content of products forces winemakers to use additional granulated sugar. The difficulty is that it is very difficult to calculate the appropriate amount of sugar, so it is better to immediately take in moderation sweet fruits and berries for homemade wine.
Why doesn't homemade wine ferment?
Not only beginners, but also experienced winemakers may encounter the problem of stopping the fermentation of homemade wine. Moreover The wine may not initially ferment, or it may suddenly stop fermenting. There may be several reasons for this, all of them require a special solution.
Why homemade wine may stop fermenting:
- Too little time has passed. Wine fungi need time to begin their work. The rate of yeast activation depends on several factors, including: the sugar content of the wine, the type of raw material, the temperature of the must, the type of starter or the type of fungus. In some cases, the wine may begin to ferment a couple of hours after the bottle has been sealed with a water seal. And it also happens that fermentation begins only after three days. Both of these situations are the norm, but the winemaker should start to worry when the wine does not ferment for more than three to four days from the moment the wort is fermented.
- The wine container is not sealed. The fact is that normal fermentation of homemade wine should occur when the product is completely sealed, that is, air from outside should not enter the wine. It is not the air itself that is dangerous to wine, but the oxygen contained in it. It is oxygen that causes the wort to sour, and the wine eventually turns into wine vinegar. It often happens that a winemaker thinks that his wine is not fermenting, because he judges by a deflated glove or the absence of bubbles in the water seal, but it turns out that the bottle is not tightly closed. As a result, carbon dioxide escapes from under the lid or under the elastic band of the glove, so it becomes deflated. The wine is still fermenting, you just can’t see it. It would seem that there is nothing dangerous in such a situation, but this is not so. The fact is that at the end of the process, fermentation weakens, the pressure of carbon dioxide becomes less strong. Because of this, oxygen from the air can easily get inside the container and spoil the almost fermented wine.
- Temperature fluctuations. For normal fermentation, the wine must be kept in a room with a temperature of 16 to 27 degrees. Fungi live and work until the temperature of the wine drops below 10 degrees and rises above 30. If cooled, the yeast “falls asleep” and precipitates, and if the wine is overheated, the fungi will simply die. Wine fungi also do not like temperature fluctuations: wine will ferment well only at a stable temperature.
- Violation of sugar content. Acceptable limits for the percentage of sugar in wine are from 10 to 20%. If these boundaries are violated, fermentation will stop. With a decrease in sugar content, the fungi have nothing to process, turning all the sugar in the wort into alcohol, they die. When there is too much sugar in wine, the yeast cannot cope with the amount and the wine is preserved.
- "Non-working" yeast. Most winemakers use wild yeast to make homemade alcohol, that is, those that are found on the peels of fruits and berries. Wild fungi are very unpredictable; they can initially develop vigorous activity and then abruptly stop the fermentation of wine. This is also possible if there is insufficient amount of yeast, when the fruits have been washed or it rained on the eve of harvest, for example.
- The thickness of berry or fruit juice. Some wine products, such as plums, currants, rowan, are very difficult to release juice; after crushing, they form a thick puree. It has been revealed that the thicker the wort, the more difficult it is to ferment.
- Mold. When preparing homemade wine, it is very important to maintain complete sterility: containers, hands, products. To avoid contaminating the wine with mold fungi, all utensils must be sterilized and washed with soda. You should not put rotten or spoiled products into the wort; they may be contaminated with mold.Moreover, it is not allowed to use material that already has traces of mold. Therefore, before preparing wine, berries and fruits are carefully sorted.
- Natural end of fermentation. When the alcohol content in wine reaches 10-14%, wine yeasts die. Therefore, homemade wine cannot be stronger (unless it is fixed with alcohol, of course). Most often, the fermentation of homemade wine lasts from 14 to 35 days, after which the process gradually slows down until it stops completely. You can find out about this by the appearance of sediment at the bottom of the bottle, the clarification of the wine itself and the absence of bubbles in the water seal design or a deflated glove.
What to do to make wine ferment
Having found out why the wort stopped (or did not begin) to ferment, you can try to correct this situation. Methods to solve the problem depend on the cause.
So, You can make wine ferment in the following ways:
- strengthen the tightness of the lid or water seal. To do this, you can use batter or other adhesive mass, which you can use to coat the neck of the bottle at the point of contact with the lid or glove. Open the bottle less often, and if you do, do so only for a few minutes.
- Provide the wine with a constant suitable temperature - from 16 to 27 degrees. If the wort is overheated, you can try adding a little special wine yeast to it - fermentation should start again.
- If the wine has not started fermenting within four days and it looks too thick, you can try thinning the must by adding a portion of sour juice or water.Liquid should make up no more than 15% of the total volume.
- Check your sugar level with a special device - a hydrometer. If such a tool is not at hand, taste the wine: it should be sweet, like tea or compote, but not cloying (like jam, for example) and not sour. You can add no more than 50-100 g of sugar for each liter of juice, otherwise fermentation will not start. It is better to add granulated sugar fractionally, in small equal parts at intervals of several days. This way the fungi will process the sugar gradually, which will prolong the fermentation of the wine.
- When the reason for stopping fermentation is poor-quality yeast or insufficient quantity, you need to add a fresh portion of fungi. They can be found in special sourdough, store-bought yeast for wine, in quality raisins or in a few unwashed grapes. These components are added to the wort and mixed.
This can be done in several ways: add alcohol to the wort, take the bottle into a room with a temperature below 10 degrees, heat the wine to 35-55 degrees (this process is called pasteurization). In all these cases, the fungi die and fermentation stops.
If homemade wine has stopped fermenting, this is not yet a reason to throw it away - the situation can be corrected. First of all, the winemaker must find out why this happened, where he violated the technology, and then take appropriate measures.
There are also cases when it is impossible to help the wine. Then all that remains is to learn from your own mistakes in order to prevent them from happening in the future.
