Lesson 6 - Yeast Propagation
This lesson explores yeast propagation, the supply of pitching yeast and its fitness for purpose. We will explore yeast cultures and the protocols for its storage, along with how to propagate new cultures within the laboratory. This knowledge will enable us to demonstrate an understanding of the design features required for a yeast propagation plant.
Lesson Information
Pre-requisite Knowledge:
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Yeast Morphology and Evaluation (Yeast/Lesson 2)
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Yeast Biochemistry (Yeast/Lesson 4)
Learning Outcomes:
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Understand why most brewers choose to use pure yeast cultures.
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Explain why some brewers choose to use mixed cultures.
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Explain the practice of serial re-pitching and why this introduces a need for propagation.
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Define propagation and outline its component parts.
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List, with an assessment of strengths and weaknesses, the methods used to maintain yeast cultures.
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Describe a typical protocol for recovering yeast cultures from storage and propagating a new culture in the laboratory.
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Describe the process of yeast propagation in the brewery together with a critical discussion of the strengths and weaknesses of traditional methods.
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Demonstrate an understanding of the role of oxygen in yeast propagation and discuss the consequences on yeast physiology of using wort as the growth medium.
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Describe the underlying design features of continuously aerobic yeast propagation plant.
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Understand the likely impact of the physiological condition of newly propagated yeast on subsequent performance in fermentation.