How do you deactivate yeast?

Answer 1

stop giving it water and/or food

yeast will also kill itself by fermentation; in a closed system the yeast will consume all it's food resources and produce enough alcohol to kill all the yeast cells.

Answer 2

The fastest, easiest way to deactivate yeast is to kill it. You can kill it by placing it in the freezer in an airtight container for a few hours.

Answer 3

microwave it!