Yeast Culturing

[Dr Strangebrew]

I am a huge whitelabs fan. I am going to use one of their seasonal yeasts in an IPA. If it turns out well I may want to use the yeast year-round. I would like to know if anyone has any experience culturing yeast. I am interested to know the process. I hope that it is something that I can do with a pressure cooker/ stock pot and a few quart jars. I have experience making yeast starters. Also, I use a secondary fermentation with all my beers. Do I harvest the yeast from the secondary or from the primary?

Thank you,

Nate

[Putney Hill]

There are a few things you can do. From easiest to hardest is:
Washing and storing under water, in the fridge.
Freezing with glycerin.
Culturing on agar.
You are asking about culturing. Do you want to work with agar?

[Dr Strangebrew]

What is agar? I'm not sure if culturing was the right word. I don't know the proprer definition of the word. I just want to be able to 'reuse' the yeast from batch to batch, until it is available the next year.

Thanks,
Nate

[jayhawk]

Here is a simple method for reusing yeast. I don't think it is true culturing, but it can work well if you are very careful about sanitation.

1)Brew a batch with desired yeast as normal.
2)Bottle the beer and carbonate naturally (ie prime it, not force carbonating)
3) Store as many bottles from this batch as you want in the fridge. These bottles will act as your yeast source for the next batch, so don't drink them unless have another source of yeast! You can reuse the yeast by pouring off the beer in the bottle and pouring the yeast sediment in to a starter mixture.
4) Prepare a starter mixture as normal. If you have stored the beer for a long time, you will want to really make sure the yeast is rolling before you pitch, so make a big starter and add a little yeast nutrient.

Make sure that the stored batch you are drawing the yeast is not contaminated or you will infect the next batch.

You can also "update" your yeast reserve by replacing bottles from older batches with ones from newer batches that use the same yeast (provided they are infection free!!!). If you brew regularly with the same yeast you should always have a fairly fresh yeast source to use.

You could also just keep brewing back to back batches and pitching the new batch on to the yeast cake in the secondary that was left from the previous batch. Ideally you will want to use only yeast from the secondary, but you may be able to get away with using yeast from the primary. The primary yeast is generally not as viable because it was the first to drop from suspension and therefore is not as good. You are also more likely to get an infection from the primary cake as bacteria can be present in the trub.

Make sense?
Chris

[Putney Hill]

http://hbd.org/carboy/yeast_washing.htm

[Dr Strangebrew]

I'll probably pot for the yest washing method described in the link because I fell in love with kegging about a year ago.

Thanks guys

Nate