Video explanation of traditional brewing and fermentation technology

The whole fermentation process is divided into four stages:

1, fermentation starts.

At the initial stage of fermentation, raw materials and water (collectively referred to as fermented mash) are in a static state, and there is no movement like stagnant water; The mash is also clear and transparent. After the start of fermentation, there are small bubbles on the surface of mash, but the number is small.

2, the fermentation is vigorous

Fermentation is vigorous. Small bubbles on the liquid surface become large bubbles, and the number is large; Fermented mash is tumbling, as if water is boiling; Carbon dioxide is strong, and the fermented mash turns from clear to turbid, with a bouquet.

3. Fermentation decline

The foam has weakened, and the smell of carbon dioxide has also weakened. The biggest feature is that the raw materials float on the liquid surface from the bottom of the fermentation container, and their quantity is about 1/5 of the total.

4. After fermentation.

The raw materials floating on the liquid surface sank again, and the fermented liquid turned from turbid to clear, and the whole fermented mash was in a static state, which proved that the fermentation had been completely completed. This phenomenon is called a sign of the completion of fermentation.

The length of fermentation period depends on temperature. High temperature and short fermentation period; Low temperature and long fermentation period. We can't say that the shorter the fermentation period, the better. Of course, we cannot say that the longer the fermentation period, the better. How to properly master the length of this fermentation cycle is an important link to improve the yield of wine and increase the taste of finished wine.

Intuitive judgment of fermentation end

1, raw materials:

When all or most of the rice floating on the surface of the fermentation liquid sinks into the bottom of the pool, the fermentation liquid turns from turbid to blue, the whole fermentation liquid is in a static state, no longer bubbling, and the rice grains no longer move up and down, which means that the whole fermentation process has been completed and the raw materials have been completely fermented.

Step 2 color

Just look at the color change of the fermentation broth. From feeding to bubbling, the fermentation broth is clear and transparent.

During the period from the beginning to the end of fermentation, the fermentation broth changed from clear and transparent to rice soup color. From the end of fermentation to esterification, the fermentation broth changed from rice soup to light brown.

Common problems in fermentation:

Practice has proved that a longer fermentation time is an important measure to improve the yield of wine and increase the aroma of finished wine.

1, how long should it be extended?

When the fermentation broth turns from turbid to clear and the whole fermentation broth is in a static state, it is advisable to extend it for another day or two. From the color point of view, when the fermentation broth changes from turbid to clear and from clear to dull light brown, it can be distilled.

2. Why extend the fermentation time for one or two days?

Because the aromatic substance of wine is protein in raw materials, it is decomposed into amino acids, and then it becomes an aromatic substance through biochemical reaction. This biochemical reaction.

Fermentation and temperature

Whether raw materials are completely fermented is directly related to time and temperature, in other words, it takes a long time to ensure complete fermentation; Short fermentation time may lead to incomplete fermentation.

The relationship between temperature and fermentation period is as follows: high temperature and short fermentation period; Low temperature and long fermentation period. Specifically, when the temperature is 20 ~ 25℃, the fermentation period is 15 ~ 20 days, and when the temperature is 25 ~ 30℃, the fermentation period is about 10 ~ 12 days. When the temperature is 30 ~ 40℃, the fermentation period is usually about 8 days.

Practice has proved that the fermentation temperature of uncooked liquor should be controlled above 20℃ and below 40℃. When the temperature is higher than 40℃, it is easy to produce acid and even the yeast dies. When the temperature is lower than 20℃, the raw meal is difficult to ferment. The optimum fermentation temperature is between 25-35℃, and the fermentation time is appropriately extended to ensure the complete fermentation of raw materials.

Therefore, when the room temperature is below 20℃, measures should be taken to keep warm and raise the temperature, and when it exceeds 42℃, the temperature should be lowered.