West Coast Brewer Home Brewing Blog

Tag: clearing


Tannins are organic compounds found in the husks’ grains. Excessive tannins are almost always considered to be a flaw in beers and are interpreted as a harsh astringent bitterness or a mouth drying sensation. Excessive tannins are typically caused by too high of a mash pH or excessive temperatures during mash out or sparging. Tannin extraction is dramatically increased when mashing or sparge water temperatures exceed 170° F. Please also note that as the lautering and sparge process comes to a finish, the pH of a mash is increasing, which compounds the potential for tannin extraction. In addition to the off flavors created by tannins, they can also be significant contributors to chill haze in a beer. Hops release tannins into beer, but the hop tannins are not considered to be significant contributors off flavors or chill haze.


Ways of removing excess tannins from beer including cold crashing, or cold conditioning the beer at approximately 34° F for two or more weeks. That should cause some of the excess tannins and proteins to precipitate out of the beer onto the bottom of the fermenter or conditioning vessel. You may also use a beer a beer fining agent such as gelatin or isinglass to help clear the tannins.



Cold Crashing

Cold crashing or cold filtering is a common method used to clarify beer. When a beer is cold crashed, it is chilled down to approximately 35 F and left for several days to several weeks. During that time, yeast and other solids tend to clump together and fall to the bottom of the fermenter or holding tank. The clarified beer is then racked above the layer of sediment and potentially ran through a filter if additional clarification is desired. Cold crashing or filtering is not appropriate for some beer such as a hefeweizen or certain Belgian ales where a yeasty flavor or hazy beer is desired.