Krausen drop in less than 12 hours with US-05

[Lezzath]

Hi everyone, I'm a baby brewer who begins in homebrewing so I have some question about my batch. As a beginner, I make small batches (5L). Yesterday I brewed a 8% ABV Stout with an original gravity of 1.077 in which I pitched Safale US-05 Yeast. And I have a question about the start of my fermentation that seems really fast.

I pitched it yesterday (01/31/24) at 8.26 pm at ~19°C, and when I woke up this morning (02/01/24) I went to see my fermentation (7.55 am), and I saw some krausen leftovers over my fermenter (glass fermenter) and a small layer of krausen on top of the beer.
I know that I have a bit overpitched my yeast, but I would like to know if it's normal to get a krausen drop that fast, and if it will have negatives effects on my future beer ?

 

[Stikius]

That seems really fast. Are you sure it's not the opposite, and that it's rather beginning to build up?

 

[Miraculix]

Overpitching is a homebrew myth. There is no such thing as an overpitch. The only thing that can happen is that temperature gets a bit out of hand when more yeast eats at the same time, but otherwise the more the better (within reasonable limits of course). You are good!

 

[jdauria]

Did you shake the fermentation vessel after pitching yeast to oxygenate the wort? Is it possible what you see as krausen is just some of the dry yeast that stuck to the top after shaking? I have never seen a krausen rise and then fall in under 12 hours. You say you pitched at 19C. but I assume you had no temperature control? Once the yeast got going, they generated their own heat and could have bumped that temp up to 23-25C or maybe even higher in a such a small volume. So maybe a hot ferment did cause a quick fermentation. Did you pitch the whole pack of US 05? A 1.077 OG would need 77-92 billion cells depending on pitch rates, so if you pitched the whole thing, you overpitched some, but that would not hurt the final product.

 

[hotbeer]

Sometimes I don't get lot of Krausen foam with US-05. Are the ambient temps fairly constant where the FV is kept? Or do you actively heat/cool the FV to maintain the beer at a particular temp?

Normally I start to see evidence of a krausen at 18 to 24 hours after pitch with US-05. And by day 3 or just after, it's already just remnants of what it was. Usually most all of the actual fermentation is done too. But don't get in a hurry, the yeast are still doing other things.

However it's still too early to be worrying. Wait till your 2 or 3 weeks is up and then see if there is any need for concern.

 

[BrewZer]

It has happened to me. Maybe your fermentation temps were a bit high...?

 

[day_trippr]

This scenario would be the outlier of all fermentation outliers. Sans a gravity check, I remain skeptical...

Cheers!