Yeast Maintenance And Propagation

Question 1

What exactly is meant by the term pure culture?

Answer 1

Single strain of yeast species grown in isolation. Free of any other strains, or microbiological contamination.

Question 2

Name a method for the following:
A: Isolating a pure brewing yeast culture
B: preserving it

Answer 2

A: streak plating.
B: cryostorage using Liquid nitrogen (must include 15% glicerol

Question 3

Name a method for the following:
A: Isolating a pure brewing yeast culture
B: preserving it

Answer 3

A: streak plating.
B: cryostorage using Liquid nitrogen (must include 15% glicerol

Question 4

3 reasons brewing yeast is propagated

Answer 4

Mutation minimization
Avoiding contamination
Consistent fermentation
Cost effective

Question 5

3 factors to consider when propagating brewing yeast in a plant

Answer 5

Wort comp
Sterility / Hygiene
Temperature
Time