Common Beer Flavor Defects Tips

Due to the existence of flavor defects, the originally soft and refreshing beer sometimes becomes incongruous and unflavorable. This has a serious impact on the taste and quality of the beer. To this end, we must not ignore the existence and generation of flavor defects.

Rough taste

Too high polyphenol content and too high degree of polymerization of polyphenols;

The hardness of the brewing water is too high and the pH value is high;

The husk of the malt is thick, or the malt is too finely crushed, and the wort filtration time is long;

Excessive washing;

Old hops, unreasonable hop storage such as long time and high storage temperature;

The time at the higher temperature of the mash is too long;

Beer oxidation, beer pH is too high, etc.

Incorrect bitterness, long after bitterness

Excessive polyphenol content and high degree of polymerization of polyphenols;

The hardness of the saccharified water is high, the pH value is too high; the content of some ions is too high;

Excessive washing of spent grains;

The wort has insufficient boiling strength and high coagulation nitrogen content;

The hops are old, the amount of hops added is too high, or the method and time of adding hops are not suitable;

The wort is boiled for too long, resulting in the oxidative decomposition of iso-alpha-acids:

Poor separation of coagulum from wort;

The fermentation is not vigorous, and the bitterness of the bubble cap is not completely separated or not separated at all;

The bitter taste of autolyzed yeast;

Oxidation of beer, etc.

Phenolic or other chemical smells

The use of water-soaked wheat and saccharification with phenol, chlorophenol and high free chlorine often leads to this taste in beer;

Use detergents and sterilizers containing free chlorine or phenols to wash the sterilization equipment and pipelines;

Contaminate wild yeast or bacteria, etc.

Aged taste

It is also called oxidative smell, showing bread smell, sterilization smell, cardboard smell and so on.

The dissolved oxygen content in beer is too high, amino acids are decomposed, alcohols are oxidized into aldehydes and ketones; fatty acids are oxidized, and lipid enzymes are decomposed. After bottling, the oxygen content is high, and after sterilization, it is very easy to oxidize; and with the prolongation of beer storage time, the oxidative smell becomes stronger.

Sour rice

Mainly because the diacetyl content of beer exceeds its taste threshold (below 01mg/L), and immature beer has this taste;

Beer contaminated with Sarcina has a strong diacetyl taste.

Rotten backgrass smell

The metabolites from yeast are mainly acetaldehyde. When the acetaldehyde content exceeds 15mg/L, this smell occurs, and sometimes the acetaldehyde content is lower than 9mg/L.

Garlic

From poor hop varieties or yeast strains and abnormal fermentation.

Onion

Is the taste of dimethyl sulfide, mainly from raw materials or wort boiling abnormally.

Yeasty

Mainly from excessive sulfide content, especially hydrogen sulfide. When the yeast ages and degrades or the fermentation and wine storage temperature is too high and fluctuating, the yeast will produce autolysis, or the coagulation will be poorly separated, the wort ventilation will be insufficient, the post-fermentation will not be prosperous, the nitrate content will be too high, and the wine will be served too early. It is easy to produce this smell.

Metallic taste

Also known as iron smell and ink smell, it is mainly due to the high content of metal iron ions in beer.

Burnt taste

The drying temperature of the caramel malt or black malt is not handled properly, or the heating method of the mashing equipment.

Sour

Infection with lactic acid bacteria, acetic acid bacteria and other miscellaneous bacteria

Musty smell

The raw material is moldy or the cork used is moldy, which causes the beer to have a musty taste, and some flavor substances can also show a moldy taste.

Wheat peel

The malt has thick husk and too finely crushed; the mash is too high for a long time; the pH is too high; the spent grains are washed too much, etc.

Thick taste

The content of dextrin is high; the fermentation bottom is low; the content of higher alcohol is too high, etc.