Malt production in beer

  Under artificial control, barley was soaked in wheat, germinated, dried and uprooted In production, the barley called pre-malting must be separated from impurity and graded. The wheat grains are divided into three grades of large, medium and small on the sieve surface with the diameter of 2.2, 2.5 and 2.8 mm, so that the solubility of soaking wheat, germination and malt can be uniform. Operating points are as follows:

1. Choice of wheat

  It is required that the net wheat inclusion after selection should not exceed 0.15%; Wheat grain uniformity, that is, the ventral diameter of more than 2.2 mm wheat grain up to more than 93%; The selection rate is generally 80% - 90%.

2. Steeping

  Take the alternate method of soaking and breaking water, that is, in the process of soaking wheat, first soak the barley with water, and then put away the water, so that the barley is exposed to the air, after repeated immersion and breaking water, has reached the required degree of soaking wheat. Now take the operation of "4 dip 4 break" as an example: at the beginning of feeding, soak in water to drift away the sludge and floating wheat, and change the water after 2 hours. Adding 1% - 3% quicklime in the wheat and secondary leaching water to make lime milk leaching wheat. Its function is disinfection, dissolving the mucus, pigment and tannin on the wheat grain to reduce the malt color and bitter taste. After that, it soaked in water for 4 hours, cut off water for 4 hours, and ventilated regularly until the moisture content of wheat grain reached 43% -- 45%. The water temperature is 17 deg c -- 18 deg c, the whole wheat soaking operation is about 60 hours, including soaking wheat for 32 hours and cutting off water for 28 hours. When soaking wheat, fresh water should be changed frequently. Compressed air should be injected every half an hour for 5 minutes -- 10 minutes. Ventilate the water 15 times for 20-30 minutes at a time to supply air and remove carbon dioxide and heat. Winter temperature is low, should be long, short water break. Summer water temperature is high, should be short, long break water.

3. pregermination

  The 0.15ppmGA treatment at the time of last wheat soaking or at the beginning of germination had a good effect on promoting the growth of yield regulation nodes. It can shorten the germination period of 2 days -- 3 days, reduce the tabulation loss of 0 -- 4%, improve the extract about 2%, promote the activity of amylase, hemicellulase and proteolytic enzyme and other enzymes, can break the wheat dormancy, improve the germination ability, and can improve the mechanical operation of wheat and low enzyme activity barley solubility.

4. sprout 

  The method of barley germination can be divided into floor type, ventilated type, tower type and continuous type, etc. The ventilated type includes the box type and the tank type. Taking the single box intermittent germination method as an example, the germination management is illustrated as follows: the barley soaked in wheat is sent into the germination box, which is immediately turned and mixed, so that the water soaked in wheat is discharged from the bottom of the box. The thickness of wheat layer is 0.6m -- 1m. The excessive thickness of wheat layer affects ventilation, and the temperature difference within the wheat layer is too large. The equipment and power of thin wheat layer are not economical, and the wheat layer is easy to dry.remove the excess water on the surface of the wheat grain, and then the wet air of 10 deg c -- 14 deg c is injected to regulate the temperature of the wheat layer and gradually increase the temperature of the wheat layer to 14 deg c within 24 hours. At this temperature, the soaked barley began to sprout after 24 hours. As a result of exhale action, wheat layer temperature rises gradually, must pass continuously 10 Celsius -- 14 Celsius wet air, control temperature, everyday raise temperature about 1 Celsius, make the 5th day achieves 18 Celsius -- 20 Celsius, continue to maintain this temperature later or drop to 14 Celsius gradually germinate. The temperature shall be kept below 20 degrees Celsius. Ventilation shall be conducted once every morning, afternoon and evening. The temperature difference between upper and lower wheat layers is 1 degree Celsius -- 2 degrees Celsius. Germination flourishing period turn and mix should be frequent, later stop turn and mix and ventilated, make root bud withering.

5. desiccation

  Indirect heating of 1-3 - stage horizontal baking towers is usually used. The structure includes a heating device, a horizontal drying bed and a ventilation device, etc. Drying beds have single, double or triple beds, each of which is called a section. General small brewery double - deck drying bed more. The baking time is 24 hours. Malt in the first 24 hours in the upper layer, should take 20 degrees Celsius - 25 degrees Celsius low temperature, strong ventilation, drainage of water, prevent wheat hydrolysis continues, reduce the destruction of enzymes, keep the endosperm powder loose state, if the temperature rises too fast, malt will harden. The temperature gradually rises to 50 degrees Celsius -- 55 degrees Celsius, and the moisture drops to 8 degrees Celsius -- 12 degrees Celsius, or the lower fujiao stage. For the light malt, it is hoped that the color formation is not much, but still retains some fragrance, and it is hoped that the solidifying nitrogen content will be denatured and solidified at a high temperature, and the grease affecting the foam can be removed. Green malt has a green smell. When the baking temperature continues to rise to 2 hours, the temperature will rapidly rise to 85 degrees Celsius, and the moisture will drop to 2%-5%, making the malt produce a burnt flavor. Strong malt is required to produce more pigment and burnt flavor. The baking temperature should be raised to 100 c - 105 c. Malt baked good standard, moisture 2% -- 4% or so, into the water is not heavy, smell of obvious barley, particle expansion, wheat ren-hair white, wheat root easy to fall off.

6. Remove the root

  The roots of the dried malt are very crisp and can be peeled off with a little friction. Therefore, the dry malt immediately after the tower must be eradicated. The root remover generally USES a slow rotation of the metal mesh roller, the speed of 20 RPM, the plate speed is fast, 160 RPM - 170 RPM, in the same direction of rotation, wheat roots are easy to fall off by mechanical shan, and the metal mesh screen. The root buds of light malt were about 2 to 3.5 percent, while those of dark malt were about 3 to 5 percent. After the detached root buds are collected and slightly cooled, they should be sealed and packaged to be used as raw materials for the production of compound phospholipase tablets.