The taste and stability of beer directly affect whether the product has the ability to participate in the market to win consumers. Only by understanding the various flavor substances in beer can it be beneficial to control the taste.
A few common flavor drawbacks:
1. Immature taste
The immature flavor is manifested as "green odor" in beer. The flavor substances that affect the maturity of beer include: acetoin, acetaldehyde, diacetal, dimethyl sulfide, hydrogen sulfide, etc., of which acetaldehyde is the The main substance of "green flavor", its threshold value is 15mg/L. Acetaldehyde is mainly generated during the main fermentation, and the oxygen supply and inoculation amount are large, which can promote the generation of acetaldehyde. Sometimes the diacetyl value of the wine is low, but it still has an immature taste, and sometimes it has a pungent sulfur smell. The sulfur-containing compounds have a great influence on the flavor of beer, mainly due to the high temperature during the main fermentation. Generally, the wine can last longer. it has been improved.
2. Higher alcohol
Higher alcohol is the main substance that forms beer flavor, but when its content is too high, it will cause headache and dizziness. The higher alcohol is mainly isoamyl alcohol, followed by active amyl alcohol, n-propanol, isobutanol, etc. The threshold value of amyl alcohol was 15 mg/L, which was mainly produced during high temperature fermentation.
3. Yeast flavor
Yeast autolysis produces various amino acids and at the same time ethyl caprate, which has a smelly yeast smell. The main cause of yeast autolysis is temperature, including the storage temperature and fermentation temperature of yeast, followed by the excessive amount of yeast added.
4. Esters
The main esters in beer are: ethyl acetate, isoamyl acetate, ethyl lactate, ethyl hexanoate, etc. Among them, the threshold value of ethyl acetate is 30 mg/L, which has fruit aroma and solvent aroma; the threshold value of isoamyl acetate is 2 mg/L, which is rubbery watery and irritating. If the lipid content is too high, an ester aroma will appear, and an appropriate amount of vinegar aroma can give the beer a unique flavor.
5. Oxidation taste
The initial oxidation performance of beer is: a very slight cardboard taste, which does not affect the taste, and this slight oxidation taste can mask other bad smells in the wine, and when the beer is strongly oxidized, it is expressed as: very unpleasant The burnt taste directly affects the taste and makes the wine lose its re-drinking ability. The threshold value of trans-2-nonenal, an aging substance in oxidized beer, is extremely low at 0.0001 mg/L.
6. Sunlight
When the beer is exposed to sunlight, the isohumulone in the beer is decomposed by light to form 3-methyl-2-butenyl, which combines with the sulfur group of the sulfur-containing amino acid in the beer to form 3-methyl-2-butene-thiol (Riboflavin in beer catalyzes this reaction). The valve ester bottom of this substance is 0.001mg/L, and it has a fishy odor and produces an unpleasant odor.
7. Unsuitable bitterness
The carbonic acid hardness of the brewing water is too high; the hops are oxidized; the polyphenol content is too high; the tryptosol and tyrosol content is too high; the yeast is autolyzed;
