Re using yeast.

[sam.k]

I'm thinking of buying a liquid yeast as I am aiming to produce a stock beer that I will always have, well, a stock of.

Now once I've found the perfect yeast I am going to want to keep using it, how many times can you recycle a yeast before it starts changing? Is there any way to slow or prevent any changes? Do yeasts get tired?
Silly questions I know but liquid yeast is new to me :)
Regards
Sam.

 

[pittsy]

Hi Sam , there are 2 ways most people do this , either simply collect the sediment and store in fridge( or wash it then store) or make a big starter and split the yeast before brewing with it .What i do is make a 4L starter with 400g of dme and ferment for a week then mix well and split into 10 to 12 330ml bottles , then when i'm ready to brew i use a botle with 100g dme and 1L water boiled and cooled , ferment for 2 days before brewing .

 

[pittsy]

p.s around 5 times yeast can be used before possible changes for better or worse and if collected yeast sediment the yeast may carry flavours from last brew

 

[Hirsty]

As long as you're uber-hygenic you should be able to use the yeast over several generations. For example, I know one brewery that is currently on its 638th generation.
I'd invest in some methylene blue though to test the viability.