Malt making of craft beer

The purpose of malting: through operation, let the barley absorb a certain amount of water, and germinate under appropriate conditions, activate the enzymes in the barley and produce various hydrolytic enzymes, so that the components in the endosperm, such as the starch and protein in the grain Etc., under the synergistic action of enzymes, it is moderately dissolved; the green malt can be dried and roasted to remove excess water, remove the green taste of green malt, and produce the unique color, aroma and flavor components of beer; Finally, the composition of malt can be stabilized for long-term storage.

Malt manufacturing process: raw barley - pretreatment - soaking malt - germination - drying - postprocessing - finished malt

The two main processes in malting are biological and chemical. Biological processes refer to awakening of dormant barley kernels; respiration of kernels and growth of roots and germs; changes in tissue structure; production or release of enzymes. The chemical process refers to the "dissolution" of malt and the change of malt flavor substances under the action of enzymes.

Let's introduce the knowledge of malting from the aspect of malting technology:

 Barley Pretreatment 

The pretreatment of barley includes: 1. rough selection of barley; 2. selection of barley; 3. grading of barley;4. Selection rate and uniformity: 5. Requirements for wheat selection; 6. Storage of barley.

 Soak wheat 

Freshly harvested barley needs to be stored for 6-8 weeks before it can be used. After the barley is cleaned and graded, it can be soaked in the barley trough. Barley absorbs sufficient water in soaking, and when the water content reaches 43% to 48%, it can germinate. During the soaking process, the dust, soil and microorganisms on the surface of the barley can also be fully washed away. Appropriately adding any chemical drug among milk of lime, Na2CO3, NaOH, KOH and formaldehyde in the wheat leaching water can accelerate the leaching of harmful substances such as phenols, promote germination, and help improve the quality of malt.

 Germination of barley 

Germination is a process of physiological and biochemical changes. Through germination, the enzyme system in barley can be activated, and the types and activities of enzymes can be significantly increased. With the formation of the enzyme system, some macromolecular substances such as starch, protein, and hemicellulose in the wheat grains are decomposed, so that the wheat grains can reach a certain solubility to meet the needs of saccharification.

Germination methods can be divided into two categories: floor germination and ventilated germination. Floor germination is a traditional method, which is relatively backward and has been gradually replaced by ventilated germination. Ventilated germination is thick-layer germination. By continuously sending fresh saturated humid air at a certain temperature to the wheat layer, the temperature of the wheat layer is cooled, and the proper moisture of the wheat grains is maintained, while the CO2 and heat in the wheat layer are discharged.

 Drying and storage 

Undried malt is called fresh malt (or fresh malt, customarily called green malt).

Drying purpose:

1. Remove excess moisture from the malt for easy storage. At the same time, the wheat root becomes brittle and easy to remove, so as to avoid the influence of wheat root components on the quality of beer.

2. The growth of fresh malt is stopped and the malt composition is stabilized.

3. Remove the fishy smell of fresh malt, and at the same time form the unique color, aroma and taste of different malts.

The drying process of green malt can be roughly divided into three stages: withering period, roasting period, and roasting period.

The derooted malt must be stored for more than two weeks before it can be released from the warehouse. Generally, dry malt must be stored for a month and up to half a year before use.

Purpose of storage:

(1) Freshly roasted and rooted malt, the bark is easily broken;

(2) After the derooted malt is stored and regained moisture, the skin can be broken but not broken when crushed;

(3) After storage and regaining moisture, the endosperm loses its original brittleness and its texture is significantly improved;

(4) After the malt is stored, the enzymatic activity inactivated by roasting is revived, the saccharification power is increased by 1% to 2%, and the protease activity is increased by 2%.

 Post-processing of malt 

After the malt is discharged from the kiln, it is cooled in a temporary warehouse and immediately derooted; commercial malt is also polished.

1. Root removal: After cooling for 3 to 4 hours, the dried malt becomes very dry, brittle and easy to fall off, so the root removal is performed immediately. Because barley root absorbs moisture quickly, bad bitterness will affect the quality of beer, so it should be removed.

2. Polishing: Malt can be polished before leaving the factory to remove rust or dust on the surface of the malt to make the appearance beautiful. Before polishing, the malt is sieved to remove large, small and light impurities.