Eight purposes and reasons of wort boiling
5.Extraction of hop resin for isomerization of hops
Put in the hops, boil the heat in the pot and drastic boiling to make the yellow glands, the hops we say, get out of the original flower and dissolve in the wort.
The hops gland contains most of the required hop ingredients. The two most important hop ingredients are: hop resin, hop oil (essential oil).
When hops are added to wort, a-acid isomerization to iso-a acids must undergo three basic processes of emulsification, isomerization and dissolution. These three processes are explained by the theory of the wort boiling function. It takes about 30 minutes for the hops to complete the isomerization rate to reach 100% but it takes 60 minutes. Therefore, in order to ensure effective isomerization, the time for adding the hop particles can not be less than 30 minutes from the end of the wort boiling.
The longer the boiling time and the more intense the boiling, the more complete the isomerization reaction. (So it can't be warm boiling water, but it should be intense boiling.)
It is the iso-a-acid that creates a clean, refreshing, short-lived bitter taste.
Although higher than the optimum pH promotes the isomerization reaction, it degrades bitterness. Under low pH conditions, "excellent" beer bitterness results.
Isoa-acid is a major factor in stabilizing beer foam.
6.Remove unwanted volatiles
Boiling can evaporate unwanted compounds, mainly sulfur-containing compounds such as Dimethyl Sulfur (DMS).
DMS is a volatile sulfur compound that has an unpleasant odor and taste similar to the “creamy corn” flavor with a relatively low threshold (approximately 50 ppb). High levels of DMS in beer are often considered to be a defect, so as far as possible, beer should not contain DMS.
At boiling temperature, the half-life of DMS precursor SMM is about 40 minutes. Therefore, the boiling time and boiling strength are very important for removing unwanted volatiles.
The process of boiling the wort has an important influence on the (browning) color of the wort.
The formation of color is caused by a complex Maillard reaction (browning reaction), which usually occurs between certain amino acids and results in the formation of a product called melanoidin.
For some beer recipes, we add ingredients to the boiling pan.
Accessories are easily dissolved in boiling wort. The continuous rolling of wort can accelerate the mixing of auxiliary materials. After the auxiliary materials are evenly mixed, it will not be formed on the bottom of the pot and become scorched and scorched.
In addition, boiling ensures that the ingredients do not cause biological contamination of the wort.
(For buddies who like to try new brewing with various accessories, they should be inspired.)
8.Creates flavor and reduces pH
As can be seen from the above table,
In the boiling process, we should consider to ensure that the functional requirements of the wort boiling are fulfilled. Among them, the more important is the isomerization of hops, coagulation and precipitation of clottable proteins, and bad volatile flavor compounds such as Volatilization of DMS and aged aldehydes. Much evaporation of water is not essential, and it is relatively easy to kill the vegetative bacteria and the enzymes of the microorganisms. If these basic requirements can be met within a short period of time, the boiling time can be shortened.
Secondly, the boiling pot equipment used must be considered, in particular, the structure of the inner heater, the conditions in which the wort is uniformly heated, the conditions of the wort circulation, and the size of the boiler boiling. Different boiled cooking equipment conditions have a great influence on the determination of the boiling time. For example, using modern new boiling equipment, the boiling time can generally be less than 65 minutes.
Therefore, from a practical point of view, shortening the boiling time means reducing energy consumption, saving costs, accelerating equipment turnover, improving equipment utilization, and increasing profits.