Term
| Green Apples or Freshly Cut Pumpkin |
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Definition
| Acetaldehyde. An intermediate compound in the formation of alcohol. Some yeast strains produce more than others, but generally it's presence indicates that the beer is too young and needs more time to condition. |
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Term
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Definition
Caused by Fusel Alcohols which are formed when the fermentation temperature is too high.
Fusel alcohols can also be produced by excessive amounts of yeast, or when the yeast sits too long on the trub. |
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Definition
| Astringency differs from bitterness by having a puckering quality, like sucking on a tea bag. It is dry, kind of powdery and is often the result of steeping grains too long or when the pH of the mash exceeds the range of 5.2 - 5.6. Oversparging the mash or using water that is too hot are common causes for exceeding the mash pH range. |
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Definition
| Caused by Diacetyl. Diacetyl is produced early in the fermentation cycle by the yeast and is gradually reassimilated towards the end of the fermentation. A brew that experiences a long lag time due to weak yeast or insufficient aeration will produce a lot of diacetyl before the main fermentation begins. In this case there is often more diacetyl than the yeast can consume at the end of fermentation and it can dominate the flavor of the beer. |
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Definition
| Found in lagers. Caused by Dimethyl Sulfides (DMS,) a compound that is removed from the wort during the boiling process via evaporation. To avoid this, the wort must be boiled with the lid off, and wort must be chilled quickly. |
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Definition
| Caused by esters which can be desirable in some styles, but overbearing in others. Lower the fermentation temperature to avoid this flavor. |
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Definition
| Caused by the improper storage of grains or hops. Ingredients pickup moisture and take on a musky character. |
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Definition
| Caused by the interaction of various phenols with chlorine-based sanitizers. If bleach is used, then rinsing with boiled water after sanitizing is the best way to prevent these flavors. |
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Definition
| Oxidation is probably the most common problem with beer including commercial beers. If the wort is exposed to oxygen at temperatures above 80°F, the beer will sooner or later develop wet cardboard or sherry-like flavors, depending on which compounds were oxidized. |
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Definition
| Soapy flavors can caused by not washing your glass very well, but they can also be produced by the fermentation conditions. If you leave the beer in the primary fermentor for a relatively long period of time after primary fermentation is over ("long" depends on the style and other fermentation factors), soapy flavors can result from the breakdown of fatty acids in the trub. Soap is, by definition, the salt of a fatty acid; so you are literally tasting soap. |
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Definition
| Skunky or cat-musk aromas in beer are caused by photochemical reactions of the isomerized hop compounds. The wavelengths of light that cause the skunky smell are the blue wavelengths and the ultraviolet. Brown glass bottles effectively screen out these wavelengths, but green bottles do not. Skunkiness will result in beers if the beer is left in direct sunlight or stored under fluorescent lights as in supermarkets |
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Definition
| This group of flavors is very similar to the alcohol and ester flavors, but are harsher to the tongue. These flavors often result from a combination of high fermentation temperatures and oxidation. They can also be leached from cheap plastic brewing equipment or if PVC tubing is used as a lautering manifold material. The solvents in some plastics like PVC can be leached by high temperatures. |
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