Hot summer, can drink a glass of fresh beer, for many people is a kind of enjoyment. At present, there are many kinds of beer on the market, such as draft beer, cooked beer, fresh beer, and the newly emerging small number of craft beer on the street There are so many different kinds of beer. How to classify beer? How do consumers choose? Where does the bitterness and aroma of beer come from? In the field of beer brewing, yeast is known as the soul of beer, and the quality of beer largely depends on the quality of beer yeast strains. Therefore, it is of great significance to select yeast strains with good performance for brewing beer with high flavor. < p > < p > beer can be divided into two types according to the yeast fermentation mode. One is the upper beer yeast fermentation method, that is, after beer fermentation, the yeast is located at the top of the fermentation tank. This fermentation method has higher temperature and produces more lipid aroma substances. This method, also known as Aier, is a fermentation method with a longer history. < / P > < p > the other method is the following beer yeast fermentation method, also known as rag. In short, after beer fermentation, the yeast is located at the bottom of the fermentation tank, the fermentation temperature is low, and the production of lipid aroma substances is less. At present, the mainstream industrial light beer such as Yanjing, snowflake, Qingdao, Budweiser and Carlsberg are all lager beer. Wang Xin, national beer evaluation committee member and national wine taster, stressed: “according to the national standard GB / T 4927” beer “, beer can also be divided into three categories: draft beer, cooked beer and fresh beer.” < / P > < p > after pasteurization or instantaneous high temperature sterilization, it is cooked beer; beer without pasteurization or instantaneous high temperature sterilization, but using other physical methods to remove bacteria and achieve certain biological stability is draft beer; without pasteurization or instantaneous high temperature sterilization, the finished product is allowed to contain a certain amount of live yeast, and the beer with certain biological stability is fresh beer. Wang Xin said, “the physical sterilization process of beer is mainly based on membrane filtration. Beer liquor can pass through the membrane. However, ellipsoidal yeast cells with a diameter of about 10 μ m (micron, length unit, 1 micron is one millionth of a meter) and proteins, microorganisms and impurities in liquor can not pass through the multilayer filtration membrane with extremely small pore size.” Many craft beer houses have sprung up on the streets of Beijing this year. Some consumers mistakenly put the small number of craft beer against the mainstream industrial beer in the market, believing that craft beer is the synonym of high wort concentration and high alcohol content. The original meaning of craft beer is handmade beer. Up to now, there is no definition of craft beer in China, and there is no corresponding national standard or specification. “There is no professional classification of craft beer. The production scale, equipment and audience of this kind of beer are very small, and the raw materials and production technology are the same as those of mainstream beer,” Wang said No matter how complex the classification of beer is, as long as consumers master an iron rule, they can choose the right beer, which is “drinkability”. Wang Xin said, “the drinkability is well understood. Regardless of individual consumers’ physical conditions and preference for unique taste, as long as a beer makes people feel comfortable and pleasant in drinking, it is a good wine.” < p > < p > of course, iron powder, who are crazy about the taste of beer, can judge whether a beer is good or bad from what main ingredients are used. For example, if beer syrup, hops products, hops extract, rice, corn and starch are used in the ingredient list, it can be preliminarily determined that this beer is a beer with light taste. < p > < p > tracing the source of beer heat, it is easy to find that the heat of beer mainly comes from alcohol and sugar. To make low calorie and low calorie beer, we should first consider reducing the alcohol content, but we should not reduce the alcohol to zero, because the non-alcoholic beer is not considered as alcoholic beverage. < / P > < p > the second way of thinking is to reduce the original wort concentration to reduce the heat of beer, but it can not be unlimited to reduce the original wort concentration, which will lead to very low original wort concentration and beer alcohol precision, beer mellow, rich taste. Wang Xin said, “the beer on the market that meets the low calorie requirements should be alcohol free.” According to the data, most domestic breweries adopt the method of dealcoholization after normal fermentation to produce alcohol free beer. The alcohol content in the liquor body should be less than 0.5% Vol (0.5 ml alcohol is contained in 100 ml liquor, which is commonly known as alcohol degree is 0.5 ℃), the original wort concentration is greater than or equal to 3.0 ° P, and the heat is about 80 joules / 100 ml. < / P > < p > many people will feel a little bitter when they drink beer for the first time, while those who often drink beer say it is fragrant. Where does this feeling come from? Wang Xin said that the bitter taste of beer was mainly produced during processing. Generally speaking, beer brewing process is divided into six steps. < / P > < p > the first step is the process of wheat germination, drying and glucoamylase production, which lasts about 11 days. “Malt is the skeleton of beer. The taste of malt in brewed beer is like barley tea or sliced bread,” Wang said < / P > < p > the second step is the saccharification process of malt powder mixed with water. In fact, saccharification is the process that enzymes release starch and protein from malt into water to obtain malt pulp. Wang Xin said, “beer manufacturers will adjust the amount of minerals in water according to the different needs of rich and light taste products. The content of water in finished beer is as high as 90%. So water is figuratively compared to the blood of beer. ” The saccharification process must be inseparable from hops, Viburnum. Wang Xin regards hops as the “muscle” of beer. The data showed that the bitterness, tannin and hop oil in hops could increase the persistence of beer foam and inhibit the multiplication of mixed bacteria, and the bitterness of beer could be affected by dosage, variety and origin. < / P > < p > the third step is to ferment the saccharified liquid at 10 ℃ for about 20 days, and the raw and astringent beer is born. In this step, yeast uses the nutrition metabolism in wort to release the “taste killing” carbon dioxide and the alcohol that brings warm sensation to the tongue. Saccharification process is the main source of most carbon dioxide in beer. Yeast, which plays a key role, is called the “soul” of beer, which shows the importance of yeast to beer. However, most types of beer consumed by consumers and sold on the market are yeast free. Of course, there are exceptions, such as draft beer with short shelf life without pasteurization. After filtration, sterilization and filling, beer can be put on the market. Wang Xin repeatedly stressed: “malt, yeast, hops and water are equally important to beer, and the taste of beer is the result of the synergy of the four raw materials.” This step is inseparable from malt and water, which is the necessary carrier of saccharification. “Beer manufacturers will adjust the amount of minerals in the water according to the different needs of rich and light taste products,” Wang Xin said < / P > < p > many consumers know that beer with low temperature and ice debris is not the most suitable drinking temperature. The best drinking temperature of beer is 10-15 ℃, because beer at this temperature can give consumers the best aroma and taste experience. Choose the right temperature beer, can you drink it? Don’t worry. You need to know your tongue. In general, the tip of the tongue is most sensitive to sweet taste, the root of tongue is the most sensitive to bitter taste, the periphery of tongue is the most sensitive to salty taste, and both sides of the tip of tongue are most sensitive to sour taste. < / P > < p > in order to taste a beer and get a uniform and correct taste impression, the iron powder of beer will inhale some air after the beer is imported, so that the wine body can fully contact with the tongue and mouth, so as to release the flavor and flavor as much as possible, and then make the wine contact with all parts of the mouth as soon as possible, and then swallow it to taste the subsequent malt aroma of beer The fragrance of wine and flowers.
look at the bubble. Pour beer into the glass. The foam of the high quality beer must be fine and dense, and the hanging cup will last for a long time. Some high quality beer foam lasts for up to 3 minutes. < p > < p > second smell. High quality beer can make people smell malt (sliced bread flavor), fresh and pleasant hops flavor, fruit aroma produced by yeast, etc. If you smell sour, sour rice, sulfur (odor) and soy sauce, the quality of beer is poor. < p > < p > three tastes. If you drink 10 ml to 20 ml beer, you will first feel the killing taste of carbon dioxide on your tongue, which is similar to the killing taste of carbonated drinks, but it will not make people feel uncomfortable. At the same time, the tongue can feel the warm feeling of low alcohol content. < / P > < p > followed by only one or two seconds of bitterness. Beer must be bitter, but the bitterness only exists in the mouth for one to two seconds. If the beer has afterbitter, it indicates that the quality of beer is poor. < p > < p > followed by the soft and harmonious taste of beer, beer can not have outstanding rough bitter, astringent, sour, sweet taste. The sugar in beer exists in the form of trisaccharide and macromolecules above trisaccharide in the body of the wine. Therefore, only a slight sweetness can be felt on the tongue and mouth when drinking, which is very close to the sweetness of sugar free snacks. If there is a prominent sweetness, the beer is not fully fermented. < / P > < p > some consumers think that light beer with low alcohol content and low original wort concentration is not liquid bread without high calorie. Another view is that the use of hops extract instead of hops or the addition of syrup, corn and starch in the brewing process of beer is not liquid bread! But is it really the case? Wang Xin doesn’t agree with consumers. She believes that there is no difference in nutritional components between beer with low alcohol content, low concentration of wort and light taste beer with hops extract and syrup. Beer, similar to wine, is a kind of original wine. It not only contains the nutrients in malt, but also increases its nutritional value after saccharification and fermentation. More importantly, it produces amino acids, vitamins and minerals that are easily absorbed by the body. < p > < p > the data show that beer contains 17 kinds of amino acids and 12 kinds of vitamins needed by human body. It is estimated that a liter of ordinary beer with an alcohol content of 3.2 degrees can produce about 425 calories, equivalent to the heat produced by 5-6 eggs, 500 grams of lean meat, 250 grams of bread or 800 ml of milk. < p > < p > Wang Xin added, “beer is mainly composed of malt, which is called liquid bread because it contains amino acids and vitamins which are easily absorbed by the human body. The original wort concentration and alcohol content only determine the amount of amino acids and vitamins in beer, and do not change the original nature of beer, which is easy to absorb and rich in nutrition