Hi there, does anyone know how 'Yeast' is collected for brewing or baking?

Question

Hi there, does anyone know how 'Yeast' is collected for brewing or baking?

Answer 1

Commercially it is cultured in a lab.

Using special techniques to separate the individual strains of yeast by growing them upon culture media that is enriched with different nutrient blends. Each blend appeals to a different strain and thus it will grow. They also grow them is different temperatures and different oxygen (aerobic), slight oxygen (mico-aerobic), and no oxygen (non aerobic) environments. Each condition favors a different yeast strain. They then can select a yeast and begin to culture it into a slurry (many yeast cells.) They can further identify the species by morphological (outside of cell) traits. This slurry is made available to the brewer, winemaker, and baker as each strain is suited for.

In the brewery the selection and culturing is the same. Yet they have a short cut to gather a slurry. They can tap into a large fermenting vessel of beer and pull-off the yeast using sterile techniques. This slurry may be used many times before it is cleaned using an acid solution. After many generations the cells begins to mutate and the culturing process is began again to isolate a viable yeast cell.

http://hbd.org/brewery/library/yeast-faq...

http://realbeer.com/spencer/yeast-cultur...

http://brewiki.org/Yeast/Culturing

Answer 2

What I have been doing in my home brew is to rack off one batch of beer and put the new batch a wort into the fermenter. That is a short cut to the culturing she talks about. I have great results it is pretty nice to see the fermentation go wild.

###I need more info about this technique as it sure make a lot of yeast.