Best way to set up a starter so it doesn't overflow??

Ok...so first beer....first yeast starter. I figured I had done all of my reading...I've got a 2L flask...made a starter that was 1.5L figuring it would be just fine. I know one wants oxygen exchange when on the stir plate, so I have one of those sponges to 'cork' off the flask. Set up the starter yesterday afternoon....this morning it is all over the floor. Typical story. I have seen a ton of threads on this. What I have not seen yet though is any suggestions for preventing this in the future. It seems silly to set up a 1.5L starter in a 2L flask if it is going to overflow all of the time. What are you guys doing to set up your starters so you don't end up with a mess every time?

A) Use a rubber stopper with a blowoff tube run to a small pail of sanitizer.
B) Use two drops of Fermcap-S, which is a food grade anti-foaming agent.

Yeah, I thought about the stopper and blowoff tube, but I thought the whole point of maximizing growth was to allow air exchange..hence the foam stopper or aluminum foil. With a stopper/blowoff tube you have no air exchange going on.

I just put some aluminum foil loosely over the opening. I use fermcap when I boil the starter. I never have blow off.

I refuse to use Fermcap, and got tired of my starters 'exploding'. Especially with WLP001. I finally said enough was enough. I purchased two 5000ml flasks. No worries now.

Any other suggestions?

Was the starter a 1.040 gravity? Higher isn't desireable, hard to believe a 1.040 would blow off.

That is a good question. I was going to check it, but after boiling I ended up with less than I had planned on. I figured I followed the recipe provided by Midwest Supplies so it should be good to go. I am using White Labs 300 Hefeweizen yeast.

aiptasia said:

B) Use two drops of Fermcap-S, which is a food grade anti-foaming agent.

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Be careful with Fermcap, there's alot of literature coming out about silicon based anti-foam agents. FDA only allows breweries to use this if they filter it out before bottling because it could cause health issues.

There are other olive oil based alternatives and ive read that some big name breweries have been using olive oil to oxygenate their wort. There may be more of a reason to use that other then just the blow off prevention.

Im also surprised for the blowoff. How fast did u have the stir plate going? I've noticed when i use mine, if i have a tighter swirl or stronger whirlpool or what have you, there isn't alot of foaming as i expected.

I had the stir plate going full blast. By this afternoon it appeared fermentation was done (~24 from start). I put the flask in the fridge and it appears as of this evening there is only about 1/4" to 3/8" of yeast settled in the bottom of the 2L flask. I expect it is more than was originally in the tub, but it doesn't seem like I got a lot out of this starter (probably because half of it ended up on the floor). Hopefully it will be good enough for my BIAB batch tomorrow. I guess it is all a learning process.

I had a starter blow out before. I don't make much more than a liter at a time now. If I need more, I'll make 2 starters.

I usually make my starters the weekend before I brew.
1st starter spins for 3 days. Then I put most of it in a 2 liter bottle. I leave some behind for a second starter. Store in the fridge.
2nd starter spins for 3 days. Decant first starter in the 2 liter and then dump the 2nd starter in the same bottle. Back in the fridge.
Brew, decant, pitch.

aiptasia said:

A) Use a rubber stopper with a blowoff tube run to a small pail of sanitizer.
B) Use two drops of Fermcap-S, which is a food grade anti-foaming agent.

Click to expand...

A is bad advice, air locking a starter on a stir plate totally defeats the purpose.

B is good advice. I have a 2L flask and do 1200-1500ml starters all the time with a drop or two of anti foam and have never came close to having an overflow. It also helps when you boil the starter to prevent a boilover.

Pratzie said:

Be careful with Fermcap, there's alot of literature coming out about silicon based anti-foam agents. FDA only allows breweries to use this if they filter it out before bottling because it could cause health issues.

There are other olive oil based alternatives and ive read that some big name breweries have been using olive oil to oxygenate their wort. There may be more of a reason to use that other then just the blow off prevention.

Im also surprised for the blowoff. How fast did u have the stir plate going? I've noticed when i use mine, if i have a tighter swirl or stronger whirlpool or what have you, there isn't alot of foaming as i expected.

Click to expand...

The FDA requires filtration because of doses used in those applications. 1) Most of the Fermcap drops out in the trub. 2) The dose is exceedingly small. Couple drops per gallons is say 60uL in 128oz. That means in a 16oz pour, even if NONE dropped out, you are talking about ingesting 8uL. The FDA has approved simethicone for use in infants (the hardest group to get approval for) of 3.6mL a day. So I guess in a way, I agree. You should keep your beer consumption under 450 beers/day to avoid going over the FDA-approved infant dose for simethicone. Side note, for adults the FDA-approved daily dose is 500mg.

get a 1 gallon jug/growler. problem solved. $4 instead of $40+ for flasks.

k47k said:

get a 1 gallon jug/growler. problem solved. $4 instead of $40+ for flasks.

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This is true...but you couldn't heat the jug directly, then dunk it in ice water to cool because they aren't made of borosilicate glass. Also, most have a round bottom and aren't very compatible with a stir bar. OP was looking for solutions that are probably stir plate compatible.