Equipment and utensils pots, ceramic cylinders, latex tube, bamboo sieve, bean bag gauze, cans or ceramic cylinders, gauze, etc.
The production method selects grapes that have not been sprayed with pesticides for15 ~ 20 days before ripening. Remove raw, green, broken fruit, moldy fruit and other sundries, and put them directly in a big pot (don't wash them), because there are wild yeasts on the surface of grape skins, which play a role in the fermentation of clear juice. After selecting, wash your hands, rub the grapes in the plate with both hands and squeeze out the grape juice. Put a bamboo sieve on the mouth of the prepared jar or ceramic jar, and filter the squeezed grape juice into the jar or jar to remove the grape stalks. Grape skins, meat, etc. on the bamboo screen are wrapped with gauze, and the residual juice is squeezed out by force, and the squeezed juice is also put into a jar or jar. Under normal circumstances, the juice yield of grapes is about 70%. The jar and jar filled with grape juice are allowed to stand12 ~ 20 hours, and the supernatant is siphoned into another container with latex tube or nontoxic plastic pipe for fermentation. In order to prevent the juice from overflowing during fermentation, the clear grape juice in fermentation tanks and tanks should not be too full, and it should be 80%-90% of the container capacity. After two days and nights, the grape juice began to ferment. When it was particularly strong, you could hear rustling and smell wine aroma. In the fermentation process, we should pay attention to controlling alcohol content, supplementing sugar in time and controlling product temperature.
The method to control alcohol content is to ferment wine with wild yeast attached to grape skin per 100 ml grape juice, and 1 g sugar can produce 0.56 alcohol content. If the sugar content of grapes is15%, the alcohol content is15x0.56 = 8.4. If the sugar content is 20%, the alcohol yield is 20 x 0.56 =11.2, which means that the grapes with high sugar content have higher alcohol yield. However, it is impossible to improve the alcohol content by relying on the sugar of grapes, and white sugar must be added. The amount of sugar added can be calculated according to the following formula. For example, to brew wine with wine 12 degree (the sugar content of grapes is 15%), the amount of white sugar should be (12-8.4) x1.8 = 6.48 g. If the sugar content of grapes is 20%, the sugar content is (1 2-1.2) x1.8 =1.44g (here1.8 is calculated theoretically. The 6.48g and 1 .44g are both 100 ml of grape juice. If it is1kg of grape juice (i.e. 1000 ml), the amount of sugar added is 64.8g and14.4g respectively. Based on this, it is calculated according to the amount of grape juice.
Fill the sugar in time. Generally, it is better to add it at the peak of fermentation. According to the sugar content in grape juice used in brewing and the required alcohol content in producing wine, the amount of white sugar added is determined.
Control the product temperature. Product temperature is the fermentation temperature of grape juice. The optimum temperature is 18℃-22℃. The temperature is too low to ferment easily; Excessive temperature is easy to cause mixed bacteria infection. At this temperature for about 12 days, the sugar in grape juice is basically exhausted, and it needs to be left for 2 ~ 3 days, and then the first separation is carried out by siphon method. Pumping out the supernatant, putting it into a jar and jar cleaned in advance, and sealing and aging. Fill it up without leaving a gap to prevent the pollution of miscellaneous bacteria in the air. You can also spray a little edible alcohol on the wine (because the specific gravity of alcohol is less than that of wine, it floats on the wine surface, which can isolate the air and prevent the pollution of miscellaneous bacteria, and also prevent the white film from forming on the wine surface). After 20 days, the second separation is still carried out by siphon method, and it still needs to be aged for 3-5 months after separation.
The technological process includes selecting materials → kneading → filtering juice → standing → sucking supernatant → adding sugar at18℃ ~ 22℃ for fermentation → standing → sucking supernatant for aging → separating and aging → finished product.
Today, there are many technical options for brewing wine. Visible machines and equipment, such as crushers, de-stemmer and fermentation tanks, all have different styles and combinations to meet the special needs of every wine brewing in the world. However, whether it is red wine, white wine or pink wine; No matter what expensive or low-cost brewing equipment is used, there are several principles that must be followed in all brewing processes.
The first one is: air is absolutely taboo! Exposure to oxygen will not only destroy the freshness of wine, but also increase the activity of acetic acid bacteria-a naturally occurring bacterium that decomposes alcohol and releases acetic acid. The electrolysis that promotes the grape to turn into alcohol is very close to the process that wine turns into acetic acid ―― only a little external force is needed, and the wine-making process is easy to change. Therefore, we must be very careful when making wine, so as not to let the air seep in and ruin the hard-won wine. Therefore, as early as when harvesting ripe grapes in the orchard, preventive measures must be taken.
It is a key step to eliminate the over-ripe grapes whose skins are broken first when they are selected and transported. Of course, it would be best if the fruits can be harvested one by one manually; However, now the grape harvesting machine has been able to handle clusters of grapes very carefully. Then spraying sulfur dioxide powder, which is an effective antioxidant, is often used to protect grapes that are sent to be squeezed into juice.
The fermentation process should also avoid exposure to air as much as possible. This spontaneous reaction process depends entirely on nature. In addition to the alcohol produced by yeast, the fermentation will release carbon dioxide at the same time, and the fruit sweat will be automatically separated from the external gas pollution. This is particularly important for the fermentation process of red wine, because red wine is usually placed in open-air vats and allowed to ferment by itself.
The last line of defense to prevent accidents caused by exposure to the air is the "pasteurized" adopted by many low-priced wines, that is, the wine is heated to a high temperature enough to kill bacteria. In this way, the oxidation can be effectively delayed, which is why California jug wine can be placed for a long time after it is opened, so that it can be enjoyed slowly. However, there is no doubt that if the wine is left for too long, the bacteria in the air will eventually penetrate into the wine, making the wine deteriorate and sour. Unfortunately, Pasteur's high temperature sterilization will also inhibit some helpful oxidation, which will destroy the mechanism of wine flavor transformation during long storage; Therefore, high-grade wines are rarely heated in this way. A famous special case is Chateau Corton Grancey, a top-class red wine produced in France.
Clarity is also one of the standards that should be achieved when brewing wine. No matter whether it is red wine or white wine, a bright and clear bottle of wine is not natural and easy to get. In the natural state, there will be hazy tiny characteristics and residual yeast residues in wine. To go through such processes as fining, centrifuging, filtration and storage, besides storage and standing, it also means injecting from the original container into another container. ) and cold stability (cold stability) and other procedures, in order to make the wine appear clear and transparent.
Purification is one of the few steps that need to be mixed with other substances in the whole brewing process. For a long time, high-grade wines have used protein to break up as a scouring agent. Shortly after the fermentation was completed, the wine liquid was moved to an original sedimentation tank. As soon as the protein is thrown into the fresh and unrefined liquor, the broken protein clot will slowly sink to the bottom. In this process, the electrostatic action will attract those annoying tiny particles. So a thin layer of blocky protein will be left at the bottom of the barrel, and a clearer wine will be obtained. In addition to protein, other refining agents include protein (milk protein) and silica-alumina bentonite clay.
Centrifugation and filtration can quickly make wine clear and transparent. Centrifugal separation, that is, the turbid liquor containing impurities is quickly rotated in a specific container and the impurities in the liquor are separated by centrifugal force. Unfortunately, however, it will also remove the characteristics needed in some wines, so high-grade wines are less and less used to separate impurities in this way. Filtering is the simplest and direct method to screen out waste particles, as long as the wine passes through layers of filter paper or artificial fiber screen. Although it will not destroy the quality of wine like centrifugal force, from the word "unfiltered" advertised on some good wine labels, it can be seen that the filtering function will also filter out the good things that should not be filtered indiscriminately. Compared with purification, centrifugal separation and filtration, static storage is obviously a negative practice. In fact, its principle is just like centrifugal separation: only it makes the heavier impurity particles gradually precipitate at the bottom over time, and as long as the container is not disturbed, a clear wine can be finally obtained. Clean wine can continue to be "stored" in another barrel. Of course, don't forget that air is still a big taboo, and you must avoid exposing the wine to air during the process of changing to different wood energy. In particular, red wine usually needs to be placed in wooden barrels for several months before bottling, and many pieces of wood need to be replaced for storage.
The law of low temperature stability is a way to harm wine, which is often used to treat it as cheaper wine. The process includes cooling the humidity in the wine tank to near freezing point. At this low temperature, some mineral characteristics, such as potassium hydrogen tartrate (acid tartar), which were originally dissolved in liquor, decreased in solubility and crystallized and separated. Have you ever seen "wine crystals" attached to the cork of wine? Although it is often mistaken for useless natural deposits, in fact, these crystals are good things-because this means that this bottle of wine has not been treated at low temperature, so that the minerals in it will not be dissociated and the essence in the wine will be lost.