Question

Which of the following method is procedure is used to access the yeast viability in the brewing industry?

(a) Methylene blue test

(b) Phenolphthalein test

(c) Safranin test

(d) Coombs test

I have been asked this question during a job interview.

I need to ask this question from Yeast Condition and Surplus Yeast in chapter Yeast Management & Microbiology of Fermentation Technology

Answer 1

Correct choice is (a) Methylene blue test

For explanation I would say: Methylene blue test is the most common procedure to access the viability of yeast in the brewing industry. In this test, the viable cells remain colourless whereas the dead cells are stained blue. Crystal violet, aniline blue, etc. are also used for accessing the yeast condition.