The wine stopped fermenting earlier than it should: 9 tips on what to do

Even strict adherence to the recipe and production technology does not guarantee that the fermentation process of homemade wine will go according to plan. It happens that after a while the release of bubbles stops and the wort stops "showing signs of life". This happens even to experienced winemakers, let alone beginners? Do not panic, most often the situation can be corrected.

First of all, you need to find out where the mistake was made, and then try to eliminate it. In this article, Vzboltai will analyze the reasons that lead to the cessation of fermentation and suggest a procedure to solve the problem in each case.

Poor sealing of the container

Quite often, the stop of fermentation is only an appearance. Due to a loose fit of the glove/seal, carbon dioxide bubbles escape through gaps rather than through special openings. Therefore, the wort continues to play, but it seems that the process has stopped.

At the same time, air entering the vessel in the later stages can lead to souring of the beverage. To prevent spoilage, you should take care of the tightness carefully and do not open the container unnecessarily.

Recommendations:

1. Check the tightness of the connection between the bottle and the closure/glove.

2. To increase reliability, cover the joints with adhesive dough or silicone.

3. Open the vessel only if necessary (for adding sugar, stirring, removing foam) for no longer than 15-20 minutes.

Inappropriate temperature

One of the most common factors that impede fermentation. The optimal temperature for the active work of yeast is 15-25 °C, plus or minus a couple of degrees.

It is important to avoid frequent fluctuations in one direction or another.

Low temperature leads to slower fermentation, high temperature leads to death of fungi. Overheating is especially dangerous.

Recommendations:

1. Monitor the temperature and maintain it at a constant level. If necessary, transfer the container to suitable conditions.

2. If the wort is heated above 30 °C (even for a short time), re-pitch the wine starter or yeast.

Insufficient/excessive sugar content

The optimal sweetness level in wine must is 10-20%. In case of strong deviations in any direction, fermentation proceeds incorrectly. Sugar is necessary for the nutrition of the yeast, but in excess, its activity decreases. A lack of it leads to a process stop altogether. The same thing happens in a very thick wort: the wine stops fermenting.

Recommendations:

1. Get an areometer and measure the level of sugar content. When tasting, the wort should be moderately sweet: not cloying and not sour.

2. When making dessert wine, sugar should be added in small portions so as not to stop fermentation.

3. If the recommended level of sweetness is exceeded, dilute the drink with water, if it is reduced, sweeten it.

Insufficient/excessive acidity level

Normal acidity of wort is about 4 pH. Fluctuations of 1.5 units in one direction or another are allowed.

Strong deviations from the norm negatively affect the work of yeast. If the acidity drops, fermentation is inhibited, and if it rises, the risk of microorganisms and diseases increases.

Recommendations:

1. Take measurements of the pH level.

2. In case of a strong drop in the indicator, add lemon juice (1-2 fruits per 4 liters of wort) or tartaric acid.

3. If the acidity is high, dilute the drink with water.

High alcohol content

Excessive alcohol level in wort leads to a decrease in yeast activity. Fungi "fall asleep" or die when the strength increases to 12-14%, falling to the bottom of the vessel as a precipitate. Usually, the increase in degree is noted after the completion of active fermentation. It can also be caused by too much sweetening of the wort. You should calculate the approximate strength at the stage of adding sugar: 1 g accounts for about 0.5-0.6 ml of pure alcohol.

Recommendations:

1. The best solution is to stop the process and move on to the next stage - clarification, aging, etc. д.

2. If you want to experiment, you can add alcohol-resistant yeast to the wine and continue monitoring.

Lack of nitrogenous compounds

Nitrogen fertilization is required for the normal work of yeast. Usually, the necessary trace elements are contained in the juice, but in case of strong dilution or sweetening of the drink, their concentration may decrease.

Lack of nitrogenous compounds is often observed in homemade wines from wild berries, vegetables, flowers fermented with wild yeast.

Lack of nutrition may be indicated by a sharp slowdown of fermentation processes in the wort after an active start or dilution with water.

Recommendations:

1. Buy ammonia at the pharmacy and add it to the wine. The amount is calculated depending on the concentration of the substance: 10% solution is added in the amount of 0.5 ml/l, 5% - 1 ml/l, etc. д. If ammonia powder is used, 0.25 g/l is required.

2. When working with store-bought yeast, nitrogen fertilization is not added, as it is already contained in them.

Appearance of mold, microorganisms

Due to non-compliance with sterility or the use of spoiled raw materials, the wine may become moldy or sour. Therefore, it is important to carefully select the fruits for the preparation of the drink, wash your hands during work and keep the dishes clean.

Recommendation:

Dispose of raw materials and start again, taking into account the experience gained.

Inactive yeast

This option is relevant if the fermentation was started on natural fungi, and all other indicators are normal. The behavior of wild yeast strains is unpredictable: they can suddenly stop working without any reason.

Recommendation:

You need to add a homemade starter or wine yeast to the wort and restart the process. You can simply add fresh unwashed grapes (5-6 pcs. for 10 liters of wort), after crushing them, or good raisins (50 g per 10 liters). But it is better to buy high-quality yeast, activate it properly and add it to the drink.

Completion of fermentation

Usually, homemade alcohol ferments vigorously for 2-5 weeks, after which the process gradually stops. However, in some cases (high room temperature, sufficient feeding, high yeast activity), the process can be completed faster.

Some yeast strains can process all the sugar in 1 week.

The following signs indicate the completion of active fermentation: bubbles have stopped forming/ the glove has deflated, the drink has brightened, sediment has formed at the bottom, the taste is slightly bitter, sour without obvious sweetness and cloying.

Recommendations:

1. Taste the wine, evaluate it visually. If the rapid fermentation is over, you can proceed to the next stage: filtration and long-term aging.

2. Take a measurement of the degree. Normally, young wine has a strength of 10-14%. If you want to strengthen it, you can add alcohol.

Update: 27.01.2019

Category: Wine and Vermouth