Stress causes wrinkles! Also in yeasts?
Yeast recycling | The physiological state of the yeast cell has a major influence on fermentation behaviour. In breweries, yeast is usually harvested at the end of fermentation and re-used for the next brewing cycle. It is important to assure optimal yeast physiology, in particular good yeast vitality, in order to use the yeast culture several times. The number of cycles is based on the experience of the brewmaster.