The brewing of craft beer rarely or almost never carrie […]
The brewing of craft beer rarely or almost never carries out the malting process by itself, and the malt of the finished product is directly crushed.
The purpose of pulverization is to increase the contact area between raw materials and water, so that soluble materials are easily leached, and insoluble materials are easily hydrolyzed and leached by enzymes.
The malt is crushed in a roller mill. The process of crushing is to separate the bark from the endosperm, so that the endosperm can be effectively decomposed.
Wheat husks: broken but not broken-it is conducive to the precipitation of the grains, and the filtration is easier
Wheat kernels: the finer the better-the sugar content increases, the chemical and enzymatic reactions are easy to proceed
The wheat kernel is crushed too finely: the wort is difficult to filter, and the lees is difficult to wash
Crushed wheat kernels too coarsely: Malt is not easy to absorb water, which is not conducive to the effect of enzymes
1. Dry crushing: traditional crushing method
Advantages: good separation of wheat husk and endosperm, simple equipment and easy operation
Disadvantages: wheat husks are fragile, and large dust is prone to explosions and other accidents
Most of the malt crushing by the method is a roller mill, which can be divided into two rollers, four rollers, five rollers, and six rollers. The commonly used ones are five roller mills and six roller mills. Dry pulverization equipment is simple and easy to operate, but it also has many shortcomings, mainly because the degree of pulverization is difficult to control when the malt moisture content changes greatly. When dry pulverization is used, the moisture content of malt is required to be between 6% and 8%. When the malt moisture is higher than 8%, it is not easy to crush into powder and become flakes; when the malt moisture is lower than 6%, the wheat husk is also easy to crush into powder, but it is not easy to form a good filter layer during filtration, resulting in filtration difficulty.
2. Wet crushing: the malt is soaked in water at 50℃ for about 15-20min
Advantages: wheat husk has good toughness, the husk is complete after crushing, and the grain layer is loose and easy to filter
Disadvantages: high power consumption required for completion in a short time, low saccharification yield, high residual sugar content in lees, and high hygiene requirements
Wet pulverization is to soak the malt in hot water at about 50°C for 15-20 minutes to make the water content of the malt reach about 30%, and then enter the roller mill (the gap between the two rollers is 0.35～0.45mm). The saccharification water (the ratio of material to water is above 1:3) is sent to the pulverizer to mix the powder, and the saccharification pot is poured into the saccharification pot while pulverizing. Since the wet pulverization pre-soaks the malt, the toughness of the husk is increased, so the husk can be kept intact after pulverization, which is beneficial to the filtration of wort and reduces the dissolution of harmful components in the husk. The disadvantage of wet pulverization is that the malt for one saccharification feed needs to be pulverized in a short time (not more than 30min), so the production capacity of the pulverizer is required to be large, the electrical load is concentrated, and on the other hand, the sanitary conditions of the equipment are higher. , Otherwise it is easy to be infected with bacteria.
3. Humidification and smashing: humidification of malt with water → the method most used in craft beer
Advantages: the husk and endosperm are separated well, and the husk is less broken
Disadvantages: the endosperm is easy to adhere to the pulverizer, dust needs to be removed, and the water content is limited