Active Fermentation, But No Krausen

I've been using a Pacman yeast strain for several generations. On the 3rd generation, I made a chocolate stout for the wife. The krausen never really materialized and I chalked it up to the oils in the chocolate.

But then I used yeast left over from that stout to make an ESB, and it had a 1/4" krausen that lasted about a day, then just lots of tiny bubbles hitting the surface and disappearing. This was in a different carboy, so residual oils shouldn't have been a problem.

Now I've got a starter going in a 1/2 gallon growler using the leftover ESB yeast, and it's doing the same thing: lots of tiny bubbles and no krausen.

The stout and ESB were both excellent beers. The ESB fermented down to 1.011 and was one of my best tasting brews. Anyone ever heard of a yeast that didn't krausen? Should I be worried? Seems if the beer is good, stay the course?!

any input would be great as i'm making this today. will be pitching in mid-afternoon.

i might go with the S-04 or US-05 standby because i just checked my notes, and i made a brown ale off the ESB primary that also had absolutely no krausen. the brown ale is still in secondary and i haven't tasted it. i hesitate to use the same strain on a fairly expensive IPA this afternoon

Probably to late here, but I'd say that if the beers tasted good, it's all good, even if they didn't look normal during fermentation. But then again you can't go wrong with US-05 in an IPA in my book.

i ended up using the us-05 to avoid any issues.

but, to continue the saga, i put the starter in the fridge last nite to sediment out before pitching. the fridge was set at 43 degrees, and today it was still fermenting away at that temp. so, maybe it mutated to a lager strain

I'm not sure if the yeast can hang on to some of those oils, but I've had no krausen with beers before, particularly ones that foamed a lot when aerated. Foam/krausen is mainly due to proteins (breaking down I THINK) but I know that these proteins can only really be used up once. Krausen is unimportant as long as it's fermenting well. Are you getting good head retention in the finished beers?

excellent head retention on the ESB and stout. haven't sampled the brown ale yet. i didn't get alot of foam when i aerated those beers, but i did get alot of foam aerating the IPA i made yesterday. it had a 1" krausen formed after about 12 hours, but that was the US-05 yeast i used.

i still have 4th and 5th generation jars of this pacman strain in my fridge, maybe i'll do a 1 gallon batch to experiment.

You are more adventurous than me LOL I never go past one generation. It sounds like you have a mutation of some kind. If it tastes good it tastes good. A no foam ale yeast would be a good find. There are low foam yeasts, most wine yeasts are low foam. Many bacteria can ferment things too. Tiny bubbles could be a sign of lactic bacteria converting malic acid to lactic acid; at least that is the classic sign of malo-lactic fermentation. I don't even know if there is malic acid in beer though LOL Do the beers taste buttery?

so far, the stout and ESB did not taste buttery. the stout has a bit of alcohol burn, but it's 8.8% and still rather young so i'd expect a little burn at this point. the ESB was one of my finest malt-forward beers. i'll probably keg the brown ale this week and take a sample. if it's promising, i might stay with the yeast.

and i would say that your wine yeast example is a good comparison. there are lots of tiny bubbles streaming upward and popping at the surface, but no foam.

i kegged the brown ale made with this strain the other day, and it tastes excellent. so, i guess i can push forward with the no krausen pacman strain. more room for beer in the fermenter!

on the other end of the spectrum, I pitched some US-05 I had for a backup and it nearly blew the airlock off my IPA. had to do an emergency airlock removal and add a blow off tube. my wife was standing nearby when i pulled the airlock and it sprayed yeast all over her. needless to say she wasn't pleased, but i did warn her beforehand!