1. Simple technological process of wine
Grapes →→→ De-staling and crushing →→ Bottle (can) →→→ Fermentation → Wine → Filter peel hawthorn →→ Malic-lactic acid fermentation (not necessary) → Siphon bottle (can) → Full bottle sealed and stored at low temperature for the winter →→→→
2) fermentation temperature: the suitable fermentation temperature for red wine is 25-3 degrees, and that for white wine is 18-2 degrees.
3) Selection of wine grapes:
Self-brewed wine pays attention to local conditions and entertains itself. There are no special rules for grape varieties, as long as it is grapes, you can try it. Friends who can't afford to buy special wine grapes, common fresh grapes (rose fragrance, longan, Kyoho, etc.) on the market can also make wine, but the taste is more distinctive. Red grapes must be used to make red wine; White (green) grapes or grapes with red skin and white flesh are used for white wine (pressed and peeled before fermentation in bottles).
The alcohol content of wine is converted from the sugar contained in grapes, and the color of red wine comes from the pigment contained in grape skins. We should choose grapes with high maturity, dark color (dark purple), fresh and healthy to make wine.
4) stem removal and crushing: gently crushing and kneading. Don't mash it to avoid crushing the grape core. The white film on the grape skin contains natural yeast, which is the treasure that grapes can naturally ferment into wine. When buying, choose healthy grapes without washing!
5) containers: plastic barrels, stainless steel pot, porcelain jars, bottles and cans are all acceptable. For a few ornamental experiments, it is recommended to use transparent glass bottles, coke bottles and mineral water bottles. Avoid contact with metals such as iron, aluminum and tin.
6) Bottle (can): Leave 2% of the capacity above the grape container to prevent the grape skins from floating and expanding to overflow the grape juice after the fermentation is started.
7) Sugar content: Theoretically, 17 grams of sugar/liter of grape juice can produce 1 degree of alcohol, and the highest alcohol content that can be achieved in natural wine brewing is 15 degrees. If the sugar content of grape juice is low-the alcohol content is low, the taste is weak and it is difficult to preserve; If the sugar content is too high-the sugar can't be fermented to produce sweet wine. Generally, fresh grapes can produce wine with an alcohol content of 7-1 degrees without adding sugar. According to the sweetness of grapes, 34 grams of sugar can be added to each liter of grape juice, which increases the alcohol content by 2 degrees; If the grape maturity is poor or the sweetness is not high, consider adding 68 g sugar/liter, that is, increasing the alcohol content by 4 degrees.
sugar adding time: the grapes are put into the jar for 2-3 days, and sugar is added when obvious bubbles appear, that is, during the vigorous fermentation period.
8) Fermentation process: Starting the fermentation as soon as possible after the grapes are bottled is beneficial to prevent the propagation of harmful bacteria, so the temperature should be controlled well after bottling to avoid too low temperature. Bubbles rising and grape skins floating are the manifestations of the beginning of fermentation. Note that a large amount of CO2 gas is produced in the fermentation process, and strong sealing is prone to danger, so it should be properly ventilated. Stirring for 1-3 times a day will make the grape skin contact with the juice as much as possible, so as to soak out the effective substances such as pigment and tannin on the peel. The normal fermentation period is about 1 week, during which a small amount of ventilation should not be kept in a sealed way, and the fermentation is finished when no obvious bubbles are generated. At this time, the grapes have been successfully turned into wine, and the subsequent process is to make the wine soft, sour and clear.
9) filtering the skin hawthorn: coarse filtering can be performed with tools such as fine stainless steel mesh (without leaking grape stones) and silk stockings, and the wine can be squeezed out by force. At this point, the operation of each subsequent process should try to avoid the contact between wine liquid and air, and avoid the oxidation and deterioration of wine.
1) fermentation of malic acid-lactic acid: not necessary. This process requires high temperature and PH value of wine, and can be started normally only under suitable conditions (acidity, temperature and alcohol content). If apple-lactic acid fermentation cannot be started, the bottle can be sealed directly. Apple-lactic acid fermentation should be isolated from oxygen as much as possible.
11) Siphon bottle pouring: after the fermentation, filter the skin residue and let it stand for about 2 days. Siphon bottle pouring once to remove the sediment at the bottom of the bottle. After 2-3 months, pour the bottle again by siphoning, and remove impurities such as tartaric acid crystals at the bottom of the bottle. At this time, the wine is clear and beautiful, and you can drink it! When siphoning, you can use a medical rubber hose or a clean infusion tube (see figure).
12) storage of wine: it should be stored in a sealed manner, protected from light, low temperature and oxygen (full bottle). Storing new wine below zero in winter for a period of time is beneficial to the formation of tartaric acid crystals (deacidification).
13) decant the wine before drinking: it is normal for the self-brewed wine to have sediment at the bottom of the bottle after being stored for several months because it is filtered by natural sedimentation. At this time, do not shake the bottle, and slowly pour the wine into a container to decant the sediment.
3. A little knowledge of wine-making auxiliary materials
Wine is a natural product, and the application of wine auxiliary materials is not necessary in the process of wine-making. The main reasons for using a large number of auxiliary materials in modern brewing technology are to ensure that there are no accidents in large-scale industrial production, poor raw materials, color enhancement, acid reduction/acid increase and meeting the physical and chemical indicators in national standards. The application of industrial auxiliary materials should be avoided as far as possible in home-brewed wine.
special yeast for brewing: the purpose is to ensure the normal and rapid start of fermentation and the thorough fermentation of sugar, and the dosage is 2-3g/1L.
Sulfurous acid (SO2 solution with 6% content): it is used to prevent corrosion, disinfection and inhibit the proliferation of miscellaneous bacteria. Appropriate addition is beneficial to the long-term preservation of wine. The national label stipulates that the total sulfur dioxide content in wine is less than or equal to 25 mg/L.
vitamin c is a nutritional supplement, antioxidant and color fixative, which is very good for color preservation of wine without any side effects. You can't buy a small package of sulfurous acid, just add one piece to a 2.5L wine bottle.