What operations do you need to make wine in summer? Traditional winemaking has the saying of resting in winter and resting in summer, which means that too high or too low temperature in summer or winter is harmful to fermentation. However, the most suitable temperature for liquor fermentation is between 20-30 ℃, and the high temperature in summer, coupled with the poor enzyme activity of traditional distiller\'s yeast, which is not resistant to high temperature, high temperature, simple fermentation and rancidity, how can liquor brewing survive safely in summer?
1、 Temperature control
Temperature control is one of the key factors in wine making or good wine making. Many teachers and Fu have summed up a set of temperature control specifications based on their own experience for many years. It is difficult to control the brewing temperature in summer, which is also one of the most important points.
The process of wine making is the process of microbial metabolism. The environment and temperature of growth and metabolism of each microorganism are different. Liquor fermentation is mainly the process of metabolism of yeast and Rhizopus, the most suitable temperature is between 28-38 ℃, so in the fermentation process, the temperature should be controlled below 38 ℃ to produce high-yield and high-quality liquor.
In summer, it is suggested that the whole grains should be soaked, digested and fermented directly, which is beneficial to control the starch concentration of the fermented grains, slow down the fermentation speed and facilitate the temperature control.
When we cool down, we can use air conditioner or electric fan and other tools to cool down as soon as possible. We don\'t need to worry about too fast temperature loss, which will lead to low grain temperature, which is not conducive to later fermentation. The best temperature after cooling is about 30 ℃. Wine making place should be shady, ventilated and avoid direct sunlight.
In summer brewing, the temperature rise and fall of the box should be 5-7 ℃, the initial temperature is generally recommended to be within 30 ℃, and the box height is about 15 cm, which is the best. Do not leave the old box or acid box. In summer, it is very simple to make a box into an old box, which is what we usually call excessive saccharification. The main purpose of making a box is to expand the cultivation of strains in the koji and the preliminary saccharification and decomposition of grain starch.
Criteria for outgoing:
(1) Knead with hand, investigate paste water, can knead small water flower;
(2) Taste with your mouth, it\'s slightly sweet;
(3) With the nose, there is a clear fragrance, and the fermented grains together should be free of odor and alcohol.
In the first 48 hours of fermentation, combined with the difference of fermentation vessel, the speed of temperature loss will be different. The top temperature of temperature demand control is within 38 ℃, and the temperature change space of 8-10 ℃ during fermentation is reserved together, so the temperature of fermentation in the tank should be controlled within 26-28 ℃.
If the fermentation temperature rises to 38 ℃ and does not rise again, the fermentation results will not be affected generally. This is that the fermented grains have entered the stage of ester production.
If the temperature is still rising, cooling measures should be taken in time to properly add some cold water and turn the lees for cooling. Because of the existence of water, the temperature of liquid fermentation is relatively simple to control.
The most simple problems of wine making in summer:
1. Saccharification old box. The old saccharification tank will cause some adverse effects on the later fermentation, resulting in high temperature rise, bitter liquor and reduced liquor yield.
2. High saccharification temperature. High box temperature will affect the activity of mold, resulting in incomplete saccharification, low utilization rate of grain, high starch content, fierce temperature rise and high temperature in the later stage of fermentation, resulting in low liquor yield and heavy sour liquor.
High fermentation temperature. High fermentation temperature will reduce the activity of yeast, while other miscellaneous bacteria in the fermented grains, such as lactic acid bacteria and acetic acid bacteria, will multiply, directly convert sugar into acids and esters, resulting in low liquor yield and low alcohol and high acid taste.