Krausen Fell During Active Fermentation

[jpb2716]

Good morning all,

Over the weekend I brewed two 5 gallon batches, a Rye IPA and an Oatmeal Stout. I made a huge starter of WLP200 Best of Both Worlds (MoreBeer exclusive) and split it between the two batches. I used a pitching calculator so I know my yeast quatities were good. I pitched the yeast into both batches Sunday night after the temps had stabilized at 66 degrees in both batches. Both are in a temp controlled fermentation chamber.

Both showed signs of fermentation within 6 hours of pitching. By Monday morning, fermentation was extremely active. By Monday afternoon, fermentation was even more active but I noticed something that I've never seen. The krausen on the oatmeal stout was starting to fall already even though fermentation was at its peak. As of Tuesday morning, both batches are still going strong but the stout's krausen has completely fallen while the rye ipa's krausen is still thick. Just to make sure, I took temp readings on both batches. Both are reading 66.3 and 66.5 degrees. Those were taken through thermowells so that's actual liquid temperature, not air temperature.

I'm assuming there's nothing wrong. Certainly, there's nothing I can do at this point anyways. I'm just trying to understand why this happened since I've never seen it happen before. What do you guys think?

As always, thanks everyone!

 

[jekeane]

take a gravity reading?

How did you split your yeast? Even using a calc to tell you the rye needed 60% of the big starter while the oatmeal needed 40% you can only ball park what each beer is getting.

I would guess the oatmeal stout had a low OG and is just mostly done.

 

[kh54s10]

After I confirm that I have active fermentation I rarely look at the beers. I never give any attention to when the krausen falls, some are quick and others last a long time. I have also never done 2 at the same time with the same yeast, so I have nothing to compare. I can't give a reason other than the oatmeal stout might be closer to being done. I would not give any more thought to it as long as you get a good FG.

 

[jrgtr42]

What were the SGs of both beers?
Even krausen falling isn't an indicator of anything necessarily wrong.
If you are still getting output through the airlock, I wouldn't worry too much.
Just keep your eyes on them and let it ride. You may want to check the gravity of the stout - it won't hurt, but there's not much you can do about it.

 

[jpb2716]

take a gravity reading?

How did you split your yeast? Even using a calc to tell you the rye needed 60% of the big starter while the oatmeal needed 40% you can only ball park what each beer is getting.

I would guess the oatmeal stout had a low OG and is just mostly done.

Good guess. I did a 60/40 split between the two. Knowing that I wouldn't know exactly what was going into each by doing this, I overestimated just to be safe. So I'm positive that I did not underpitch.

 

[jpb2716]

What were the SGs of both beers?
Even krausen falling isn't an indicator of anything necessarily wrong.
If you are still getting output through the airlock, I wouldn't worry too much.
Just keep your eyes on them and let it ride. You may want to check the gravity of the stout - it won't hurt, but there's not much you can do about it.

OG of the stout was 1.058, the rye was 1.069. I used a higher pitch rate when calculating the rye ipa.

I still have a TON of activity through the blowoff tubes of both batches. That's why I'm confused. I've never seen a krausen fall in the middle of active fermentation.

 

[jekeane]

OG of the stout was 1.058, the rye was 1.069. I used a higher pitch rate when calculating the rye ipa.

I still have a TON of activity through the blowoff tubes of both batches. That's why I'm confused. I've never seen a krausen fall in the middle of active fermentation.

it is odd that the strain would behave differently but could be a factor of something random like rye vs oats who knows. Im sure they are fine though. Im always surprised by what 1469 does for me. 1/2 the beers it behaves normally and the other half the krausen never falls and I have to break the cap to get it to drop.

 

[GHBWNY]

Never mind the kraussen, never mind the airlock activity. Let it ride a couple weeks, take an FG and call me in the morning.