Expert: John Snyder - 9/7/2007

Question
QUESTION: Hi John,

I am wanting to start culturing my own yeast. i would like to use sediment from some commercial bottled conditioned beers, is this possible and how can i go about doing this. Thanks for your time any information given would be greatly appreciated.

Cheers Brad

ANSWER: Can you be more specfic about,about culturing your own yeast?By that do you mean growing a culture from a yeast cell,or simply retrieving yeast from another source,EX from a unpasturized,or a non sterile filtation filling of a keg.By commercial bottled condition beer,do you mean beer that has had yeast added,at filling for carbonation?With this info,i will be able advise as to what you can,and can't do

         John

---------- FOLLOW-UP ----------

QUESTION: what i want to do use the sediment from a couple of bottles of coopers pale ale as the yeast for a brew. would i just put the sediment in a sterile bottle add water and honey put an airlock on it wait for the yeast to become active then add this to the fermenter with a fresh brew?

ANSWER: I hate to disappoint you,but the process you are describing would be a waste of time and effort.Yeast in this condition,is barely viable,if at all,and would require a full scale micro lab,and microbiologist to try and revive a yeast in this state.The microbiologist would try to grow a few cells,in a medium,followed by step growth until there were enough cells to start a lab sized brew.Yeast at pitching into a brew,ranges from 10 to 15 million cells.
I would purchase that yeast,if possible,then harvest,from a fermentation.the procedures to reuse this yeast can be done,fairly easy at home.The yeast could then be reused 5 to 10 times,if done correctly.If interested in this approach,let me know,and I will give instructions.

         John

---------- FOLLOW-UP ----------

QUESTION: Hi John,
Thanks for that. i am interested in the process of reusing the yeast as you mentioned could you tell me how to do this. And will doing this improve my brew.
Cheers brad


Answer
1---after the primary fermentation has finished,put the fermenter in the refrigerator
2---after 1 week,transfer the beer,from the fermenter into a secondary fermenter,keg,or bottling bucket
3---swirl the yeast,in the fermenter with a little beer that was left behind
4---pour the yeast slurry into a clean and sanitized storage container and place in refrigerator.

NOTES:

1---Use a glass container fitted with a sterile cotton plug,or a plastic container with a screw top,because yeast slurries can build up pressure

2---reuse the yeast within two weeks

3---maximum yeast reuse after fermentation should be 5 times,meaning,each fermentation the yeast is collected from,counts as 1 time,so after pitching the first time,the yeast is now considered the 2nd generation,for the next pitching

4--- great care has to be used in sanitation and sterilization,as an infected yeast,will ruin your beer

5---fermentation will improve,as the yeast will become acclimated