Re pitching

Recovering yeast after fermentation and repitching is possible if the cell count is controlled to give the correct yeast pitching levels. In order to do so, it will be essention to have laboratory equipment to control them.  The same equipment will allow to remove bacteria by acid washing in carrefully controlled conditions.

In case of yeast repitching, yeast must not be stored out of beer for long periods, even at low temperatures. The risk being that yeast glycogen levels fall and may cause slow fermentations.

Yeast mutation are rapidly observed in brewing environments, and repitching can become a delicate operation and cause beer quality issues in terms of flavor, yeast settling or diacetyl absorption.

Effects of repitching can be seen in as few as 3 to 5 brews especially when it comes to diacetly reabsorption, even though this is less critical in Ale beers which are more flavoursome.