Lesson 4. Calculation of wort composition
Using the tables given in the previous lesson, let’s try, using the example of individual fruits, to calculate the composition of the must required for making wine.
1. Grapes
First, let's take ripe, sweet grapes - it's easiest to make wine from them.
The acidity of the juice of such grapes, for example, is ~ 0.7%. There is no need to dilute this juice with water.
The sugar content of such juice, for example, is ~ 25%. This means there is no need to add sugar either.
Suppose we want to prepare 10 liters of wine.
According to the data given in Table 1, juice yield from 10 kg berries for grapes is approximately 7.5 liters. To get 10 liters of juice we will need to collect 13.3 kg of grapes.
Squeezing the juice from 13.3 kg of grapes, we received 10 liters of must consisting of pure grape juice with an acidity of 0.7% and a sugar content of 25%. Having fermented, such a wort will give us a natural wine with a strength of 12% by volume, and the 5% of sugar remaining after fermentation will give the taste of semi-sweet wine. You can drink and have fun.
2. Cherry
Now for a more complex example.
Suppose we want to make 10 liters of semi-sweet wine with a strength of 12% vol. from cherries.
The sugar content of our cherries, for example, is 9%
and acidity – 2.1%.
In order to obtain the minimum required (for making wine with a strength of 12% vol.) amount of sugar in the wort (20%), we need to add another 11% sugar “from the store” to the 9% of the cherry’s own sugar. But this would be the case if there was no need to dilute the juice with water. And we have high acidity of fruits - 2.1%, but we need - 0.7%. That is, the acidity of the fruit is 3 times higher than necessary! This means that you need to add “the same amount” of water to the juice twice, taking into account the diluted sugar, which will also participate in reducing the acidity.
As a result of adding water, our acidity will drop, but the sugar content will also drop by 3 times and will no longer be 9%, but 3%. And this means that we do not have enough sugar up to 20%; it is no longer 11%, but 17%. But we want to get not dry, but semi-sweet wine, with 3-5% sugar remaining after fermentation. It is this 3% of its own sugar remaining after fermentation that will be used to sweeten the wine. That is, we still need to add all 20% of sugar (preferably even more) to the wort “from the store”.
I described this in such detail in order to explain that when making wine from fruits with a high acid content (3-4%), the content of own sugar in the berries (5-10%) must be neglected, and rely only on purchased .
20% sugar in 10 liters of wort is 2 liters. And we know that 1 kg of sugar dissolved in wort has a volume of 0.6 liters. This means that to obtain a wort sugar content of 20%, we need to dissolve not 2, but 3.3 kg of sugar in it.
Since the acidity of our cherry juice is 3 times higher than necessary, to determine the required amount of juice in the wort we need to divide the entire volume of the wort (10 l) by 3.
We find that our wort should contain 3.33 liters of pure juice. The remaining 6.67 liters will be taken up by: 2 liters - dissolved sugar, and 4.67 liters - water.
According to table 1, we determine that out of 10 kg. You can get 6.5 liters of juice from cherries. And we need 3.33 liters.
We calculate and find that to obtain 3.33 liters of juice you need to collect 5.12 kg of cherries.
Thus, in order to prepare the must from which we want to make our wine, we need:
1. Garden cherries – 5.12 kg.
2. Sugar – 3.3 kg.
3. Water – 4.67 l.
The composition of the prepared wort will be as follows:
1. Cherry juice – 3.33 l.
2. Dissolved sugar – 2.0 l.
3. Water – 4.67 l.
After fermentation, such a wort will give us 10 liters of semi-sweet cherry wine with a strength of 12% vol. with sugar remaining in wine after fermentation – 3%.
3. Blanks
Now let’s try to calculate the composition of the must for making wine from unused homemade preparations.
Suppose we have some left over from previous years and unused:
4 pcs. – three-liter jars of apple compote;
3 pcs. – liter jars of cherry jam;
6 pcs. - half a liter jar of black currants grated with sugar.
This amount of ingredients, taking into account added sugar (if necessary) and water, should be enough to prepare 20 liters of wine.
Let's try to calculate.
One 3-liter jar of compote contains approximately 2.5 liters of diluted apple juice, with 0.6 kg of sugar dissolved in it and 0.5 liters of digested apples.
Four 3-liter jars of compote will give us 10 liters of diluted apple juice, in which 2.4 kg of sugar and 2 liters of apples are dissolved.
Now let's get to the jam.
One liter jar of jam contains approximately 1 kg of sugar, which occupies a dissolved volume of 0.6 liters. The remaining volume - 0.4 liters - is occupied by cherries.
3 liter jars of jam will give us 3 kg of sugar and 1.2 liters of digested cherries.
Now black currant.
One half-liter jar of grated black currant contains approximately 0.5 kg of sugar, which occupies a volume of 0.3 liters. The remaining volume - 0.2 liters - is occupied by mashed currants.
We have six of these jars, which in total will give 3.0 kg of sugar and 1.2 liters of currants.
Thus, we received a wort with the following composition:
Sugar – 8.4 kg, which is 5.04 l.
Diluted apple juice – 10 l.
Apples – 2 l.
Cherries – 1.2 l.
Black currant – 1.2 l.
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In total, this amounts to: 19.44 l.
The volume missing up to 20 liters can be topped up with water.
In order to make a normal, semi-sweet wine, it is necessary that the sugar content of the wort be approximately 25%.
25% for a 20 liter bottle is 5 liters.
We have 5.04 liters of dissolved sugar. This means that we do not need to add sugar to the wort.
Acidity, in this case, does not make sense for us to calculate, as they say - what we have is what we have. As a rule, it is within acceptable limits, since jam and compotes are not made sour.
The pulp contained in the wort and consisting of apples, cherries and currants must be carefully filtered and the wine must be fermented.
As if that’s it – winemakers with experience, in principle, can already begin practical exercises in preparing wine.
For the rest, we continue classes.
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