Question

why do yeast multiply so fast​

Answer 1

Explanation:

During the aerobic phase there is a presence of oxygen in the brew, during this phase there is a rapid increase in yeast and an almost exponential growth of yeast. ... This since yeast does not grow well 'anaerobically' but needs the presence of oxygen to grow

Answer 2

Explanation:

90 minutes

Yeast has a phenomenal growth rate and can duplicate itself every 90 minutes by a process called budding.