On the five factors affecting yeast fermentation

Talking about the five factors affecting yeast fermentation

3. Touch key operation mode. The fermentation ability of yeast is very important to the brewing process, but the fermentation ability is affected by many factors, mainly including the following points:

first, the selection of yeast

different kinds of yeast can ferment different kinds of sugar. Therefore, we must choose the appropriate yeast according to the type of fermentation sugar provided by the variety of raw materials. At present, beer yeast is the most common strain of alcohol yeast. It can ferment the decomposition products of mold amylase, such as glucose and maltose. It can also ferment galactose, sucrose and 1/3 raffinose, but it does not ferment lactose. Most yeasts have sucrase, which can ferment sucrose, but the fermentation strength is different. When making wine from sugarcane molasses, yeast with strong sucrose fermentation should be selected; When making wine from grain raw materials, yeast with strong glucose and maltose fermentation should be selected; With beet molasses raw materials, we should choose yeast with strong fermentation sucrose and raffinose

second, the fermentation power of yeast

fermentation power, that is, the capacity of fermented sugar to produce alcohol. If we only focus on brand awareness to further expand and cultivate robust yeast, even if the number is large, it is not enough. In the final analysis, yeast is used to turn sugar into alcohol. Only with high alcohol conversion rate and small residual sugar can it be called a yeast with strong fermentation ability

according to the measurement, among the general alcohol yeast, rasse12 alcohol yeast has the most fermentation power to ensure the sustainable development of its battery supply chain, followed by K yeast and old Muntz yeast

third, the proliferative power of yeast

yeast that can reproduce a large number of living cells in a short time can be called a good yeast. In the fermentation environment of Baijiu production, there are quite a lot of miscellaneous bacteria. After yeast enters the fermented grains, it must be able to reproduce rapidly in a short time, and occupy an advantage in quantity and space, so as to gain a leading position in the competition with other miscellaneous bacteria, make the fermentation proceed normally, and get better alcohol production

IV. acid and alcohol resistance of yeast

with the progress of fermentation, the acidity of fermented grains continues to increase, and the temperature and alcohol content also continue to increase. Acidity and alcohol level hinder the growth and fermentation of yeast, and high temperature also leads to the passivation and inactivation of enzyme system. Therefore, in the late stage of fermentation, fermentation is often stopped due to too high intensity, too high temperature and too high alcohol concentration

each yeast has different abilities of acid resistance, alcohol resistance and high temperature resistance. In the production practice, the author found that yeast with strong acid resistance, high temperature resistance and alcohol resistance should be selected for brewing in hot places or in summer. In this way, the fermentation can last for a long time and improve the yield of wine

among the common yeasts, old Muntz yeast has the best acid resistance, and it can tolerate more than 2.0% lactic acid after determination; K yeast can tolerate 1.8% lactic acid; German yeast No. 12 has a slightly poor acid tolerance and cannot grow in 1.5% lactic acid

v. yeast fermentation products

there are many kinds of yeast, which produce other metabolites in addition to alcohol fermentation. The main fermentation strains of ordinary Baijiu are generally those with strong alcohol fermentation ability. However, in order to ensure the quality of wine, the ester and acid production capacity of yeast and the yield of fusel oil should be considered when selecting strains. For example, Hansen's yeast is a strain with high ester production, which is often used as aroma producing yeast. However, this strain produces fusel oil, which not only saves raw materials and energy, so the dosage should not be too large, otherwise it will bring peculiar smell to the wine. (end)