Krausen into the Airlock

Brewing Processes
1

It can happen.  Only when one uses an airlock, of course.  :slight_smile:

With my current brewing set up, I’ve got about 50 batches under my belt.  Today was the 3rd time I’ve ever experienced Krausen rising high enough to reach the airlock in my Speidel.  I have a 3.2 gal fermenter that I routinely fill with 3 gallons of wort.  That sounds dicey, but despite the mfg. specs, there is clearly another gallon’s worth of space to the very top of the fermenter.  I know this from sanitizing.

This beer was a simple 1.050 Cream Ale, mashed at 151, with 2-row, a touch of Vienna, and a touch of flaked corn.  BRY-97 on the job.  I’ve used BRY about a dozen times and love its predictability.  It will start for me in 7-10 hours, get all worked up by about 30-36 hours and gradually finish.  Great yeast, steady performer.

This batch started as usual, signs of life 7 hours post pitch.  At about 18 hours it was picking up steam and at about 30 it appeared to be at peak Krausen, exactly what I am used to seeing. But this morning, about 42 hours post pitch, I noticed the foam had reached the airlock.  Odd.  I set up a blowoff and went to work.  Now, 52 hours, the yeast is still going ballistic, the blowoff jar is discolored from spill-over and the bubbles are more rapid than anything I’ve ever experienced with BRY-97.  Ferm temp has been relatively steady, around 62-64 F.

Two batches ago, I had something similar happen with US-05, in a Pale Ale.

The last beer I made was a Stout with BRY, everything going smoothly.

One last thing, the first time this happened to me was about a year ago - with this exact same recipe, only with K-97.  So of the 3 times I have experienced this, twice have been with this Cream Ale recipe.

So I ask, RDWHAHB?  Or could there be something more sinister going on?

I assume this can be recipe and process dependent, but other than using a blow-off from now on, any advice?  I know many of you here are familiar with BRY-97, have you ever experienced this yeast just going rogue like this?

Thanks in advance.

2

I had a similar incident about a year ago using US-05, cannot say anything about BRY as I am not sure I have used it yet. My incident was with an IPA that started out as predicted, but after two days it had built up enough pressure, somehow managed to plug the airlock and peeled off the lid slightly and made a mess inside my fermenting chamber. At that time I found that my temperature controller had failed, it did not turn on the cooling when it should have causing too high a ferment temperature 76 or 78 degrees inside the chamber when I noticed the problem. I figured that the high temp caused the problem, replaced the controller and have not had a similar problem since. fortunately, the beer was saved.

3

I vote RDWHAHB. I’ve had blowoff a bazillion times and just shrug it off.

4

I’m really not concerned about the blow-off, more about the behavior of the yeast.  I thought I used BRY-97 enough times to know its behavior, but this activity seems out of its wheelhouse.  At least for me it is.

Maybe the real question should be, “Can this be predicted?”

Given a healthy yeast, are there clues that might suggest a certain wort is in for a rather vigorous fermentation?
Low mash temp?
Minimal adjuncts?
Overpitch?

5

I have had big blow-offs often enough that I start out using a blow-off tube every time.  If it ends up not needed, I put on an airlock.  I think it’s just easier than the clean-up for no real effort involved.

Temperature seemingly has a lot to do with it but some yeasts have greater tendency to be very active. I haven’t ever tracked the events to know what does what, though.

Paul

6

I use Bry-97 in ~95% of my beers. I get blowoff when my 5.5 gal turns out to be ~6 because when I transfer from the kettle I get foam and it’s hard to tell where I am in the fermenter.

7

My unscientific observation is that it may be related to protein content of ingredients.

8

I’m wondering if airlocks themselves aren’t the culprit.  :-\

Had I originally set up a blow-off, I wonder if the Krausen ever would have reached the top of the fermenter in the first place??

9

I think the easy answer is to use a large enough fermenter to pretty much rule out the problem.  I use a spunding valve and ferment under light to moderate pressure most of the time anymore and never have a problem with blow off, but my fermenters typically have significant headspace, anyway.

As to airlocks being the problem, yes, if using a pressurized fermenter would prevent the situation from arising, then the airlock is pretty much out of the equation…though I blow a full keg of sanitizer out of cleaned kegs (and into a separate bucket) with the CO2 produced during fermentation - which is kind of an airlock in a sense.

10

Same here. I use a 7.9 gallon fermenter for 5 gallon batches and don’t have blow-offs. I can’t say if it would work for higher gravity beers - mine are in the 1.050 - 1.057 range. And temperature needs to be controlled.

11

Well, my practical (ie. “cheap”) side can’t rationalize buying a new fermenter because 1 in 15 brews pulls a Crazy Ivan.  I’ll happily set up a blow-off from now on for insurance.

Either way, it still feels like treating a symptom…

12

It’s pretty much standard practice.  Its no more.  treating a symptom then adding hops treating the “symptom” of sweet wort.  Ever been to a commercial brewery and seen the blowoff setup for a 100 bbl. fermenter?  2 " tube into a trash can full of sanitizer.

13

I got you.

Still, I’ll keep looking for a reason as to why this happens less than 10% of the time.  Maybe there is no one reason.  Actually, it’s very likely there is more than one reason.

14

I think the reason is we’re dealing with living organisms and agricultural products and so there are countless variables at play.

Some grains have different constituents that others along with added sugars that may account for wort composition differences, some hops may contain components that contribute in ways that are not understood, some yeast may have a propensity to do things others don’t, wild yeast or flora of your home may contribute, water chemistry high in this or low in that may contribute, barometric pressure of the fermentation vessel vs the environment may play a role, and on and on…

Given a healthy sugar solution and plenty of healthy yeast, it pretty much operates within its own time schedule, progresses at its own pace and produces byproducts (alcohol, CO2, krauzen, …) as it pleases.

All we’re doing as homebrewers is setting up the parameters for nature to provide us with a successful pint.  The result is a gift.

15

Very well put.

16

I love it when my airlock gets dirty, that’s how I know the yeast is happy!

I did a german wheat with wyeast 3638 on saturday and look at it today…

CuL1o19.jpg
CuL1o19.jpg3024×4032 2.17 MB

akYohpo.jpg
akYohpo.jpg3024×4032 1.91 MB

HAp13Vj.jpg
HAp13Vj.jpg3024×4032 2.88 MB

I just rinsed out the airlock with tap water. Didn’t even bother with sanizer.

17

…or the fermenter is too small for the volume of wort fermenting.

18

I would agree with this if it happened for every fermentation.  But if it happens <10% of the time, then there has to be a different explanation, or an additional explanation.  My opinion.

19

Absolutely… wort composition, yeast strain, pitch rate, temp, etc… all contribute to fermentation volatility.

(maybe I missed where he said it only happens 10% of the time. [emoji2369])

20

3638 needs at least 25-30% headspace; it produces the mother of all krausen. Anything smaller than 7 or 8 gallons is “too small” for a 5 gallon batch of that stuff.