Wine production technology

Red wine must be brewed with red grapes, which can be red-skinned and white-fleshed grapes or red-skinned and red-fleshed grapes. The red color of wine comes from the red pigment in grape skin, and synthetic pigment must not be used.

There are many ways to make red wine. The same characteristics are: removing stalks, squeezing, and then putting the pulp, stone and peel into a fermentation barrel for fermentation. In the process of fermentation, alcohol fermentation and extraction of pigment and aroma substances are carried out simultaneously. Fermentation barrels or tanks need to be treated with low doses of sulfur dioxide to prevent microbial contamination. When grape juice is fermented in vats to produce alcohol, the peel and pulp are soaked in grape juice, and the pigment and lasting strength of wine will be released within 5-7 days.

The brewing method of red wine is generally traditional fermentation (there are also rotating pot method, carbon dioxide impregnation method, hot leaching method and continuous fermentation method). The brewing process is as follows:

process flow diagram

After the picked grapes are transported to the winery, they are pressed (to separate the pulp and juice from the grapes), pedicled (to remove the highland barley flavor of the fruit stalks) and fermented for the first time (during the fermentation, tannins and red pigments in the grape skins will penetrate into the fermented grape juice, which is called impregnation). The soaking time is usually 4-5 days or 2-3 weeks, depending on the type of red wine. Brewing "new wine" with low tannin content, soft taste and easy to eat will take a short soaking time; Brewing red wine that can be stored for a long time needs enough tannins, so it needs to extend the soaking time. ) → Extracting naturally flowing wine from fermentation tank (dropping the wine) → Squeezing grape residue (to obtain more squeezed wine containing tannic acid) → Carefully mixing the naturally flowing wine with the squeezed wine (mixing) → Alcoholization (that is, lactic acid fermentation or post-fermentation, which transforms sour malic acid in the wine into more supple and stable lactic acid) → Clarification (precipitation, separation, fine filtration) → Aging (stored in vats for 6 months to)

A good dry red wine should have the following characteristics:

(1) There are natural ruby red, purple red, pomegranate red and so on.

(2) It is a typical variety of this dry red wine. It depends on the integrity and maturity of the grapes. Generally, the relative density of grape juice is at least 1.090- 1.096.

(3) The acid content of wine should be 5.5-6.5g/l, and the maximum acid content should not exceed 7.0g/L. ..

(4) The content of tannin in wine is low, which should not make the wine astringent (in the fermentation process, the residue will be in contact with the wine for a long time, and some tannins will be dissolved in the wine).

(5) The wine should be fermented as completely as possible. The residual sugar content is less than 0.5%.

(6) Strong and long aftertaste, soft taste, full body and perfect feeling.

(7) The wine is strong but not strong, mellow and harmonious, and there is no astringent, dry and stinging smell.