Lesson 7 - Yeast Propagation SAQ
This lesson enables you to test yourself on the material covered in Yeast Propagation, and determine the level to which you have met the learning outcomes.
Suggested Response - Q1
*Answer all three parts of this question
a) Give a definition of yeast propagation.
b) What criteria are used to judge methods used for preserving yeast cultures?
c) *What is considered, at present, to be the best method of preserving yeast cultures for long term storage?
Response:
a) Propagation is the periodic introduction of a new yeast culture of guaranteed identity and purity, into the brewery.
b) Yeast should be stored in a way that ensures it remains pure, does not lose viability and is preserved in a way that does not cause any genetic variants to arise.
c) The best method currently considered for preserving yeast cultures is storage in liquid nitrogen at -196 ºC.