Will my yeast please stay in my Flask!

OK this is getting ridiculous, I made a 500ml starter in my 1000ml flask put it on my stir plate and it still over flowed. Just about every time I'm making a starter stepped up from a culture I leave over 50% head space and then it still over flows. I thought it was only a small amount of yeast escaping as the next morning I would find brown crusty stuff on my stir plate and it did not seem like much.

Well that was before I tried this experiment. My starter over flowed but I made an over flow chamber with wort in it so it could catch the excess and make more yeast (see photo). I also wanted to find out how mush was escaping

The flask with the stopper was on a stir plate and in less than four hours exploded 40% (a guess) of the yeast in the stir plate flask into the over flow.

This photo shows how much yeast is in the second (overflow) flask on the right, there is a bit of trub in the second container (but not much, < 10%)

I thought I would post this as I'm sure I'm not the only one who thought that there was not too much yeast escaping. Well I guess I was wrong!

Clem

1 drop of fermcap-s would prevent that. I don't like to use it, but it is amazing stuff.

Thanks for the tip, i knew about this stuff in the boil did not know it was for starters during fermentation. I think the reason I had not used it before was I like to try to keep things simple and easy dimethylpolysiloxane does not sound simple. I might have to start using it for my starters else get a 5000ml flask for a 1500ml starter!

Or I have two flasks to make a double starter linked with the tube on two stir plates.... OK OK OK I'll go get some.

Nice simple overflow solution. I have only had one or two blowoffs on starters. Strange that it is a persistent problem for you.

Oh, and get some food in that fridge. At least some beer sitting in there. That yogurt looks lonely.

passedpawn said:

Nice simple overflow solution. I have only had one or two blowoffs on starters. Strange that it is a persistent problem for you.

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I'm stepping starters from Slants and I'm trying to work out what size steps I'm happy with and how long to stir for, not only based on readings and discussions on this forum but from some science. So I might be stepping a bit too small and hence the yeast is really fresh and really able to go to town on the wort.

passedpawn said:

Oh, and get some food in that fridge. At least some beer sitting in there. That yogurt looks lonely.

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It is a beer fridge a fact my wife constantly wants to disgrace with things such as yogurt just cause the beer's all be drunk. 10 gallons of APA on the way... well once the dry hopping is complete.

Clem

slants are on my "next thing to try" list. I've frozen (on glycerine) a lot of yeast, but I think I'd prefer to grow it and ensure good colonies.