Bright beer is beer that has fully clarified and is free from haze, nearly all particulates, and yeast has fallen out of suspension.
Cold filtering or cold crashing is a common method used to clarify beer. When a beer is cold filtered, it is chilled down to approximately 35° F and left for several days to weeks. During that time, yeast and other solids tend to clump together and fall to the bottom of the fermenter or holding vessel. The beer is then racked above the sediment layer and potentially passed through a filter if additional clarifying is desired. Cold filtering is not appropriate for some beer styles, such as hefeweizens or certain Belgian ales where a yeasty flavor or hazy beer is desired.