Craft beer is brewed with little or no malting process itself, and the finished malt is directly crushed.
The purpose of crushing is to increase the contact area between raw materials and water, so that soluble substances are easily leached, and insoluble substances are easily hydrolyzed and leached by the action of enzymes.
The pulverization of malt is carried out in a roller mill. The pulverization process is to separate the wheat husk from the endosperm, so that the endosperm can be effectively decomposed.
1. Crusher Crushing requirements:
Wheat husk: broken but not broken–conducive to the precipitation of wheat grains, easier to filter.
Wheat kernels: the finer the better – increased sugar content, easier chemical and enzymatic reactions.
The wheat kernel is too finely crushed: the wort is difficult to filter, and it is difficult to wash the grains.
The wheat kernel is too coarsely crushed: the malt is not easy to absorb water, which is not conducive to the effect of enzymes.
2. Crusher Crushing method:
1. Dry crushing: the traditional crushing method.
Advantages: good separation of wheat husk and endosperm, simple equipment and easy operation.
Disadvantages: The wheat peel is easily broken, and the dust is prone to explosions and other accidents.
Most of the malt pulverization uses roller mills, which are divided into two-roller, four-roller, five-roller, and six-roller. The commonly used are five-roller and six-roller.
Dry grinding equipment is simple and easy to operate, but it also has many shortcomings, mainly when the moisture content of malt changes greatly, the degree of grinding is not easy to control. When dry grinding 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 be crushed into powder, but becomes flakes; when the malt moisture is less than 6%, the wheat husk is also easily crushed into powder, but it is not easy to form a good filter layer during filtration, resulting in filtration. difficulty.
2. Wet crushing:
Soak malt in water at 50°C for about 15-20min
Advantages: The toughness of the husk is good, the husk is intact after crushing, and the bottom layer is loose and easy to filter.
Disadvantages: large power consumption required to complete in a short time, low saccharification yield, high residual sugar content of wheat grains, high requirements for hygiene.
3. Humidification and crushing: humidification of malt with water → a method commonly 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, and dust needs to be removed to limit the water content.
It is to humidify the malt with water or steam before crushing, so as to increase the moisture of the wheat husk, increase its flexibility, and achieve the purpose of breaking but not breaking when crushing. There are two methods of humidification, namely water mist humidification and steam humidification.
The malt is in contact with water mist or steam through the screw propeller. The temperature of the water is 30°C, the contact time is 90~120s, and the moisture of the malt is increased by 1.5%~2.0%. When steam humidification, the introduction must be low pressure dry steam (0.05~0.1MPa), the spray time is 30~40s, and the malt moisture increases by 0.7%~1.0%. During humidification, the temperature of the malt should not be higher than 30°C, otherwise the enzymes in the malt will be damaged.
Moisturizing and moisturizing can keep the integrity of the husk, which is better than dry grinding and similar to wet grinding; on the other hand, the husk is immediately crushed after moisturizing, and the content of the wheat kernel still maintains the original moisture content , which can not only ensure the degree of pulverization, but also can be stored in the powder silo for feeding, which is superior to wet pulverization and similar to dry pulverization.
4.Crusher Dipping humidification method
It is a continuous impregnation, humidification and pulverization method that emerged abroad in the 1980s. It is represented by the equipment of the German Hopman Company. At present, many large breweries in my country have introduced and adopted this new process and equipment.
This method is to store all or part of the dry malt once saccharified in the malt silo, the malt enters the humidification cylinder, and a water humidifier is installed at the entrance of the humidification cylinder, soaked in warm water for 60s, so that the bark absorbs water to about 20%, and then Enter the roller mill to be pulverized, and the pulverized malt powder is sprayed and slurried with warm water to achieve the material-water ratio required for saccharification.
Finally, the prepared mash is sent to the mashing pot with the mash pump. The equipment used in this process is more flexible. The dipping, pulverizing, pulping, and conveying equipment can be designed as both separation equipment and multi-functional overall equipment according to capital and manufacturing conditions.
5.Operation process and method of small counter-roll malt mill – dry powder method
1. Equipment inspection: Check whether there are impurities in the hopper of the pulverizer, there can be no foreign matter between the two rollers, whether the parts are fastened, whether the power cord is connected well, and whether there is any bareness. Whether the motor is grounded and other accessories are normal, if there is no abnormality, prepare to smash.
2. Raw material inspection: Before the malt is crushed, carefully check the appearance quality of the malt and whether there is mildew. The crushing amount of each batch of different wine types is: barley beer: barley malt 50-60kg (determined by malt quality), caramel malt 0.5-1.0 kg; wheat beer: 25-30kg each of barley malt and wheat malt;
★Special attention: barley malt should be used immediately after powder, and should not be stored for a long time, let alone overnight.
★Special attention: When the coke malt and rye malt are crushed, do not moisten the water.
3. Add the malt into the hopper and start crushing. During the crushing process, take samples at any time to check the crushing situation of the malt. According to the thickness of the malt powder, adjust the roller distance and feed amount appropriately. The ratio of coarse and fine particles is 1:2.5.
4. The operator should wear dust-proof equipment when crushing. It is strictly forbidden to put hands into the hopper during the crushing process, and smoking is strictly prohibited in the crushing room.
5. Post-processing: After crushing, cut off the power supply, recycle the memory materials, clean the dust on the equipment and clean the ground.