Malt Crushing in Beer Brewing

Malt crushing is the first step in the craft beer process. The purpose is to increase the contact area between raw materials and water. Although raw material crushing is only a simple physical processing process, it is the first beginning of beer brewing production (the beginning of beer brewing in the true sense is malt making). Different types of beer brewing and production must different types of malt. The technical conditions of the germination process and the technical conditions of the coking process are also different, so that different types of malt can be made, which are suitable for the brewing of different types of beer.

Raw material pulverization includes malt pulverization and auxiliary raw material pulverization. The pulverization of malt can be divided into dry pulverization, humidification pulverization, wet pulverization and immersion wet method. But, the degree of pulverization is very important to the biochemical changes during saccharification, the composition of wort, the filtration speed of wort, and the improvement of raw material use. Excessive pulverization will increase the dissolution of harmful substances in the husk and affect the quality of beer. , it will also increase the difficulty of wort filtration; too thick will affect the use of effective components of malt, reduce the leaching rate of wort, and increase the cost of raw materials for beer brewing production.

Method For Crushing Malt

• Dry Crushing

Dry pulverization is a traditional pulverization method. The requirements for the quality of malt crushing are that the malt skin is broken but not broken, and the endosperm is ground into fine powder as much as possible. Breweries use roller mills to grind malt, which has the advantages of simple structure, easy maintenance and convenient change. Under the action of pressure and friction, it is crushed by rollers, and the endosperm is crushed from the husk. The crushing process can be done once or several times. Usually, some components in the powder often need to be pulverized again, so that the pulverization degree of malt can reach the ideal need.Small and medium breweries use roller mills for dry grinding.

• Wet Grinding

When the malt is dry milled (which is common in most breweries), even with protective measures taken, the husks are damaged to varying degrees, limiting their usefulness as a filter medium. If the malt is soaked before the malt is crushed, the husk and the malt content will absorb water and become elastic, and the malt content can be separated from the husk and crushed, with little damage to the skin. Its filtration capacity is improved, and the crushed malt content can be better broken down.

• Moisturizing And Crushing

The malt is humidified with water or steam before being pulverized to increase the moisture of the bark, increase the flexibility, and achieve the purpose of breaking but not breaking when pulverizing. There are two methods of humidification, water mist humidification and steam humidification. The malt is brought into contact with water mist or steam through the auger.

• Dipping Humidification Method

The immersion humidification method is a continuous immersion humidification pulverization method that emerged in the 1980s, represented by the equipment of German companies. At present, many large breweries in China have 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 with warm water to adjust the slurry to achieve the material-water ratio required for mash.

Specific Process

• Soaking: The malt is transported to the temporary malt storage bin above the pulverizer, and soaked in water at 30-50°C in the vertical bin. The mash pump circulates the water into the temporary malt storage bin from below to ensure that the malt is soaked . The process lasts 15-30min. Through soaking, the moisture of malt increases by about 30%, the absorption of water also increases the volume of malt by 35%-40%, and the enzymes in the malt are also activated.

• Pump out soaking water

• Saccharification and cutting: the malt after soaking enters the crushing roller with a distance of only 0.45mm through the feeding roller, the husk is almost not damaged, and the content of the wheat kernel is squeezed and separated from the husk, so wet crushing The crumbs looked like grains of wheat piled together. The uncrushed wheat kernels cannot be decomposed, but enter the mash mixing tank unchanged, so the crushed material needs to be circulated for some time.

• Flushing: Intensive flushing of the shredder in contact with the malt through the installed nozzles.

The Purpose Of Malt Crushing In Brewing

The reason brewers crush malt is to make the substances in it more accessible to enzymes. There are actually some nuances in this, as the effect of smashing is different for each species, and even between varieties within a species.

• Increase The Contact Area Of Raw Materials And Water

The surface area of the pulverized raw material is many times larger than that of the original whole raw material, which increases the contact area between the raw material and the water. Make starch granules absorb water and soften . In particular, the malt itself has a thick skin, which is very difficult to absorb water, and it is not easy for water to soak it soft. But, after crushing, it is very easy to absorb water, soften, expand and dissolve if the malt skin is damaged.

• Leach Malt Soluble Matter

After the barley is germinated, part of the starch and protein become soluble, and these soluble substances are wrapped by the epidermis of the malt, which can only be dissolved after the malt is pulverized. Play a role.

• Promote The Dissolution Of Poorly Soluble Substances

Most of the malt substances are insoluble, and must be converted into soluble substances by the action of enzymes or heat treatment. For example, starch must go through the action of amylase and saccharification enzyme to make starch first turn into dextrin and then into sugar to dissolve in water. Protein must have the function of protease to decompose high molecular protein into low molecular weight protein and amino acid, and dissolve in water. Because the contact area with the enzyme is increased after pulverization, the opportunities for these insoluble substances to contact the enzyme dissolved in water are increased, so that the effect is fast, and the insoluble substances can also become soluble substances, so that the use rate of raw materials is improved.