Yeast Problem - What do?

[wyatttho]

Hi HBT,

The other day I attempted my first AG batch, an American Stout, using BIAB. My postboil OG was determined at 1.069 after temp corrections, and using Mr. Malty, I initially pitched 3g of rehydrated dry yeast as I'm only making a gallon batch. It was bubbling vigorously for the first day or two, but around day 3 slowed drastically, and there's practically no krausen - if there is it's not nearly as much as I've seen before. With the idea that I didn't pitch enough yeast, I pitched about 2g additional last night, but today when I checked it seemed that fermentation was extremely slow (like what you might consider to put into secondary slow). I'm nervous to overpitch, especially after not seeing any changes from last night. Would anybody here possibly be able to offer advice on what I should do?

Thanks!!

 

[SledgeH]

You already know that fermentation started so I wouldn't worry about it at all. Let it be for a week and check the gravity at that time.

 

[johngaltsmotor]

Have you taken any gravity readings? With a healthy yeast at the correct pitch rate and ideal temperature and oxygenation you could simply be done with primary fermentation. If it was bubbling initially and stopped that likely means that the yeast have consumed all the sugars.

Some yeast strains don't create as pronounced of a krausen or you could have gotten something in that reduced the surface tension so the bubbles break instead of accumulating.

 

[wyatttho]

Let it be for a week and check the gravity at that time.

That's probably what I'll do. It's going, but just seems awfully quick to have finished most of already.

If it was bubbling initially and stopped that likely means that the yeast have consumed all the sugars.

Some yeast strains don't create as pronounced of a krausen or you could have gotten something in that reduced the surface tension so the bubbles break instead of accumulating.

Could be. And about the surface tension - interesting! Well, I've used Safale US-05 (American Ale) before for an IPA and saw a large one, but it could've been like you said.

 

[BeerGrylls]

you didn't overpitch, and krausen / airlock bubbles are a poor way to determine fermentation activity. Best to do like the other say, wait a bit longer and do some gravity readings with a hydrometer.

 

[johngaltsmotor]

I don't know what common things could have gotten in to reduce the surface tension, but Fermcap can be added to cut down on foaming in the kettle or the fermenter. I know that it makes the krausen less than 1/10 of what it would be otherwise.

Yes, S-05 typically makes a sizable krausen initially. I've never done a 1g batch to know for sure but I wouldn't expect that to change how long the high krausen stage lasts.