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.