Why cooled wort need to aeration? And How to aeration?

Saccharomyces cerevisiae is a facultative microorganism that grows under aerobic conditions and undergoes alcoholic fermentation under anaerobic conditions.
Before entering the fermentation stage, the yeast needs to be propagated to a certain amount, which requires oxygen.

Therefore, the yeast should be supplied with sterile air into the cold wort to make the dissolved oxygen in the wort reach 8~10mg/L.

In order to enhance the dissolution of air in the wort, very small bubbles must be introduced and mixed with the cold wort in a vortex.

wort aeration