When I make a starter I usually place 3.3 Oz of Briess golden light DME in a 2 liter flask and let it boil for one minute than cool to 80F. This usually takes about an hour. I then place it in a 1 liter flask, add some yeast nutrient and place it on a stir plate. I have been using a stir plate for about 1.5 years and probably made 14ish beers using the yeast made this way. The last two times I have made a starter; within 24 hrs some of it has foamed out of the flask. From what I am reading this is not an issue but I am curious if anyone knows why, all of the sudden, this started to happen? I used some yeast I never used with a stir plate before. WLP320 and WLP570. I don’t believe I every had this problem with my go to yeast WLP001 or WLP005.
My first thought is the room temp. It has been a strange year here in Iowa with high temps hanging on, seemingly, forever and often higher than “normal”.
You also may have gotten fresher yeast than you are used to. If your supplier (or their supplier) changed suppliers the packages may have more viable cells in them (assuming liquid yeast).
Or it might aliens. ;D
Paul
I use Fermcap in my big Belgian starters which are close to the top in my 5 L flask. Works like a charm.
Its the yeast, some strain have a giant krausen. Belgians and wheat yeasts are the hardest to keep in the flask, you might need 50%+ head space to contain them. Not sure of the mechanism, maybe they are producing albumins or other head-promoting compounds.
Why not just keep it in the two liter flask?
That’s what I was wondering. Why the transfer to a 1L flask after boiling in the 2L flask? Many will boil in the flask, cool and pitch the yeast. As other’s mentioned above, certain yeasts create bigger krausens than others.
That’s what I do:)
How much volume are we talking about anyway? Don’t think this was indicated. I typically stick with about 1.2L in my 2L flask. When I bump to 1.5L I might have a foam-over.
Thanks for the answer. I thought it may be the type of yeast had a lot of krausen but going from none to all out made me question that assumption. About why I don’t keep it in a 2 liter flask…I never thought about it but that was what I was taught to do so that is what I did. Had decent beer that way, scores 35 to 39ish in competitions, so I just kept the mindless practice and focused on other things to improve my beer. Going to change that in the future. Also, thanks for the answer on how to solve the problem in the future if it persists in the 2 liter flask.
I would also say that you can turn the speed of the stir plate down. It doesn’t have to have a tornado going to bottom. Just as long as you are getting good surface movement to allow the beer to degas and take in O2
There are also big flasks, I have some 5 liter ones that are usually used for lager yeast starters, but would work fine for those ones like Belgian yeasts that create a big Krauzen (3787).