Beer is made of malt and hops and fermented by yeast. This is a carbonated, sparkling and low-alcohol beverage. The alcohol content of beer generally does not exceed 4%. The name "beer" is transliterated from foreign languages, such as Germany and the Netherlands, which call it "Bier"; Britain calls it "beer", Romania calls it "Beria" and so on. Because barley malt is the main raw material of beer, the Japanese also call beer "ale".

Before Bian Xiao, I also introduced some famous beers in the world and China, such as Budweiser and Tsingtao Beer. Next, the production technology of beer is introduced.

(1) Production of raw materials

1, malt is one of the main raw materials of beer.

In the process of wheat selection, barley is required to be large in grain size, rich in starch, strong in germination, fresh in straw flavor, with starch flavor when chewed, and the starch content should be above 60% (the more the better). When brewing beer, double-sided or six-sided barley is usually selected and made into "malt pulp" after germination for brewing.

2. Brewing water

In beer, water accounts for 90% ~95% of the finished product, which has great influence on the taste and brewing technology of beer. Therefore, the demand for beer brewing water is much higher than other alcoholic beverages. The six main salts in water have different effects on beer quality: the level of bicarbonate will affect the acidity of wort; Sodium salt is a substance that gives beer rich and heavy luster; Chloride can make malt volatilize sweet taste and improve taste and softness; Sulfate affects the taste of hops; Calcium salt can cause protein precipitation in the boiling stage of beer brewing, while magnesium salt can nourish beer yeast.

Step 3 hop

Hops, also known as hops, are indispensable raw materials in beer production. Hop itself is rich in bitter substances, tannins and hop oil, of which the content of bitter substances accounts for about 4%, forming a refreshing and faint bitterness in wine. It can also prevent the propagation of spoilage bacteria in beer, kill lactic acid bacteria and acetic acid bacteria produced in beer fermentation, and increase the durability of beer foam. Tannin content accounts for about 13% of hops, which precipitates protein in wort and plays a role in purification. Hop oil is a mixture of aromatic oils, and its content in hops is only 0. 3% ~ 1%.

4. Yeast

There are many kinds of yeasts, and beer fermentation needs special beer yeast. The function of beer yeast is to convert maltose into by-products such as alcohol and carbon dioxide. There are two kinds of yeast: upper fermented yeast and lower fermented yeast. The upper fermentation yeast is used for the fermentation of upper fermentation beer. Carbon dioxide and foam produced during fermentation make yeast float on the surface of liquid. The optimum fermentation temperature is 10~25℃, and the fermentation period is 5~7 days. Low-alcohol fermented yeast is used for the fermentation of low-alcohol fermented beer. It is suspended in the fermentation broth during fermentation, and then coagulates and sinks to the bottom after fermentation. The fermentation temperature is 5~ 10℃ and the fermentation period is 6~ 12 days. There is no difference between the two yeasts, and the fermented beer has its own advantages in taste, body and aroma.

(B) the production process of beer

The production process of beer can be divided into the following steps.

Selection and germination of wheat

Select high-quality barley according to certain standards and wash it according to the particle size. Then the barley was soaked for 3 days and sent to the germination room for germination. After strict temperature control and humidity control, malt can grow. It takes about 1 week for the amylase produced by malt to reach the required amount.

2. Pulping

Air-dried malt is crushed, mixed with hot water and stirred to make what the brewer calls "malt pulp".

Step 3: Boil the pulp.

The wort is filtered by the filtering device and then flows into the brewing tank. Then the wort is boiled in a brewing tank, and hops are added, usually 1.5 ~3h.

4, cooling and fermenting

Aft boiling, hop precipitate is filter out, and that precipitated protein is separated by centrifugation. The wort is cooled to the fermentation temperature of 5℃, and then transported to the primary fermentation tank. A certain amount of new yeast is added for primary fermentation, which generally lasts for 5~ 10 days. Most of the sugar and alcohol in the fermentation slurry are decomposed by carbon dioxide to obtain draft beer.

5. heat generation

Draft beer will be aged for two months at low temperature (below 0℃) in the regulating tank, and the beer will gradually mature, carbon dioxide will gradually dissolve into harmonious taste and aroma, dregs will precipitate, and the color of the wine will become transparent.

Step 6: Filter.

Mature beer is centrifuged to remove impurities, and the wine color is completely transparent to amber, which is draft beer.

Step 7 disinfect

Low-temperature sterilization (i.e. "pasteurization") is to soak or spray the beer container with hot water of 60-65 degrees for 20-60 minutes, so that the yeast stops moving and the wine can be preserved for a long time.

8. Packaging sales

Bottled or barreled beer can be labeled, packaged and sold after inspection.

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