Overpitching is when too much yeast is pitched into the wort. If this occurs, the most common symptoms is a very yeasty-flavoured beer, beer that is fermented too quickly and has high fermentation temperatures as a result. This is a very uncommon in a home brewing setup for the following reasons:
- Most yeast packets- even liquid yeast starters- are considered by experts in the field to be either *just* enough yeast to ferment a 5 gallon batch or even to be underpitching.
- It takes a lot of yeast to overpitch.
Over pitching is most likely to occur when a home brewer is re-using yeast from a previous batch. Over pitching can occur when you pour fresh wort on top of a yeast cake of a previously fermented batch of beer.
