Views: 30 Author: Site Editor Publish Time: 2023-02-08 Origin: Site
Characteristics of wort
The rate of fermentation depends first of all on the degree of separation of cold and hot coagulants in the wort, the oxygen supply to the wort and the composition of the wort. This cold coagulum is mainly formed when the wort is boiled due to protein denaturation and aggregation, and the continuous oxidation and polymerization of polyphenols in the wort. Cold coagulum is the agglomerated protein and polyphenolic substances produced during the cooling process of wort.
The rate of alcoholic fermentation increased significantly with the increase of temperature, while the rate of fermentation slowed down at low temperature. In the main fermentation process, the adjustment and control of the fermentation temperature is the most important part of the fermentation process management. The proper temperature adjustment can determine the pros and cons of the fermentation degree. Often due to improper temperature adjustment, the fermentation will be abnormal. Phenomenon, especially the temperature fluctuates high and low, it is easy to cause early precipitation of yeast, weakened fermentation power, no sugar reduction at the end of fermentation, low fermentation degree, weak bubble formation, or insignificant phenomenon in high bubble period. After the main fermentation starts, the yeast gradually propagates, and the fermentation temperature gradually increases. From the initial temperature to the high fermentation temperature, the method of natural heating is adopted without manual control. When the maximum fermentation temperature is reached, the cooling pipe is used to control the temperature to continue to rise through cooling water. The temperature should drop slowly when starting to cool, otherwise it will cause yeast to precipitate and affect fermentation.
The contact area between yeast cells and wort is very important for material transformation. The contact area expanded with increasing yeast cell concentration. Less yeast can be added when fermentation starts earlier. The actual dosage should be based on the freshness of the yeast, the consistency of the yeast, and the number of generations of yeast used. If the inoculation temperature is low, the inoculation amount should be slightly larger, and vice versa. The total amount of yeast added depends on the start time of fermentation. It is generally required to add After the yeast, fermentation begins soon in order to inhibit the reproduction of other bacteria.
Mechanical movements of beer equipment, such as circulation and stirring, can strengthen the contact between yeast cells and wort, and make fermentation vigorous. The mechanical action increases the wort circulation, so that the yeast is fully exposed to sugar and oxygen, which can promote its initial fermentation. Since the traditional one-tank method or two-tank method for beer production uses static fermentation, and no stirring is installed in the main fermentation equipment, the cycle is mainly realized by the difference in carbon dioxide concentration.
The change of sugar is reflected in the final parameters of beer fermentation: true fermentation degree and apparent fermentation degree. The true degree of fermentation is to add water to the original volume after evaporating the ethanol in the wine and measure its concentration, and then calculate the true degree of fermentation.