Most fruit juices contain too much acid and too little sugar. Without stabilizing the wort, the wine turns out to be very sour and not strong enough. Only some grape and apple juices do not require correction, in other cases, you can not do without the intervention of the winemaker. There are methods that allow you to normalize the acidity and sugar content, minimally affecting the organoleptic properties of wine.
Determine the initial acidity of the juice can be a special device – “pH meter” or reference tables of the content of acids and sugar in fruits. It is advisable to use data from your region. The average data is displayed in the tables.
Balanced wines are considered to have 4-6 grams of acid per liter. During fermentation, the concentration drops, so the initial acidity of the wort is made higher – 6-15 grams per liter.
Sometimes, for example, in pear juice, it is necessary to increase the acidity of the wort. The easiest way to do this is by adding the right amount of citric acid (juice). The juice of one lemon contains 4-5 grams of acid.
Methods of reducing the acidity of wine
Attention! It is necessary to reduce the acidity before or during fermentation (except for settling in the cold), working with the wort, and not the finished wine.
1. Dilution with water
The most common method used by almost all home winemakers. One drawback is that the extractivity of wine decreases, as a result, the drink loses some of its aroma and taste.
Water reduces the acidity of the juice by half. It is important to take into account the added sugar. After dissolving 1 kg of sugar, it increases the volume of the wort by 0.6 liters, reducing the acidity in the same proportion as water.
Let’s say there is a juice with an acidity of 18 grams per liter and a sugar content of 8%. If we want to reduce the acid content to 6 g / l, we need to dilute it three times (18:6=3), that is, add 2 liters of water to 1 liter of juice. But the acid concentration also decreases due to the added sugar, so its volume must be subtracted from the calculated amount of water.
1 gram of fermented sugar (natural and introduced) gives 0.6% alcohol in the wine. A total of 200 g/l of sugar is required to produce a wine with a strength of 12%. In the example, the volume of wort is planned to be 3 liters, to obtain a given strength, 600 grams of sugar will be required. At the same time, 80 grams are in the juice itself, which means that during fermentation you need to add another 520 grams (600-80). This sugar will occupy a volume of 0.312 l (520×0.6). Reduce the amount of water by this volume (2-0. 312=1.688 liters).
Therefore, to prepare a wine with a strength of 12% and an acidity of 0.6%, you need to add 520 grams of sugar and 1.688 liters of water to the juice with the initially set parameters. At first, the calculations seem complicated, but in fact, if you understand the essence, everything is simple.
2. Blending of juices
The idea is to mix the sour juice in certain proportions with other non-acidic, equalizing the overall acidity of the wort. It is advisable to mix the juices of some fruits, but different varieties. For example, grape with grape (red with red), apple with apple, etc. If the fruits are different, in most cases the wine turns out to be tasteless.
Unlike adding water, mixing juices does not reduce the richness of the taste, this is the best method to lower the acidity, but in home winemaking is rarely used, because it is difficult to find a suitable material for blending.
3. Introduction of acid quenchers
Adding substances to the wort that neutralize the acid. These can be special powder chemicals (used according to the instructions) or folk remedies: chalk, gypsum and eggshells.
First, the shell is washed, the film covering the egg from the inside is removed, then crumbled into small pieces. Chalk and plaster can be put entirely or pre-pounded. Part of the wine material is cast into a separate container and mixed with a quencher. To neutralize 1 gram of acid, 1 gram of chalk or eggshell is required. When the precipitate falls, the juice with reduced acidity is added to the main wort (without sediment). The disadvantage of the method – after neutralization, an unpleasant smell may appear.
When the temperature drops to 2-4°C, acid salts precipitate. The method is used for both wort and finished wine, with its help you can reduce the acidity by 1-1. 5 g/l, which is very small. Cold can only fix wines with a small excess of acid.
High temperature lowers the acidity of the wine, but this method has a number of disadvantages, including: folding of proteins (reduced extractivity), the appearance of” cooked ” taste, loss of flavor, death of yeast. Because of this, boiling is almost never used.