The bitterness of beer mainly comes from the hops added during the boiling of wort. The bitterness of beer may be due to the following reasons:
1. The addition ratio, the higher the addition ratio of hops, the heavier the bitterness is. If the alpha-acid content of hops is higher, then, the same proportion of addition, the bitterness of the beer will be heavier.
2. The PH of the wort and the boiling strength of the wort, the high PH of the wort and the strong boiling strength will isomerize the bitter resin. Therefore, when the PH of the wort is high and the boiling strength is high, if the proportion of hops added is not Adjusted accordingly, wort and beer will be slightly bitter, but adding hops to boil under high pH conditions will make the bitter taste more vulgar.
3. Adding method and adding time, if a large proportion of hops are added in the early or middle stage of boiling, it is easy to cause a heavy bitterness, and the time of adding hops is too early in the boiling process, it is easy to cause a heavy bitterness. If a higher proportion of hops is used for the last addition, the wort cannot be separated in a short time during the filtering or clarification process, and the wort will be bitter. Standing time, otherwise the α-acid in the hops added in the last time will be further isomerized and dissolved at high temperature, and the bitterness will be increased again.
4. The oxidation of wort will make the B-acid contained in the hops rapidly oxidatively dissolve and increase the bitterness. The solubility of the oxidation product of B-acid is higher than that of iso-a-acid, and it has a strong bitter taste. Therefore, if hops are added The higher the B-acid content, the more intense the wort churning during boiling, and the clarification under the conditions of high temperature, opening, and long time will increase the bitterness.
At present, most of the requirements for the bitterness of beer are slightly bitter or not bitter, and the measured value of bitterness should be 15-25 EBU. Therefore, the following aspects should be controlled:
a. Strictly control the addition ratio and addition amount. For beer with general concentration (10-12BX), when adding beer raw material hops, it should be controlled at 0.1%.
b. Control the appropriate addition time and addition method. If the addition time is too early, the degree of bitterness is good, the addition time is too late, the isomerization effect is poor, the bitterness is not good enough, and the utilization rate of hops is not high. In addition, the addition method is also very important, including several additions, whether it is wet addition or dry addition, the amount of each addition, etc., and the control is good, which can ensure the palatable bitterness of the beer and save the hops.
