What is "jumping" in my beer?

Can yeast "jump"? There has been several times where I've opened up the closet to check on the beer... check the temp... see how things are going and I've noticed what appears to be a good sized clump of yeast literally propel itself from the bottom of the carboy up about 3/4 of the way up the carboy and then move back down to the bottom again.

The acceleration on these clumps are super fast... it seems like they make it from the bottom up towards the top of the carboy in a fraction of a second (like 1/4 or 1/8 of a second) and then move (or fall) down at about 1/3 the speed they rose. The size of these things appears to be about the size of 2 long grain rice grains stuck side by side.

I'm sure this may be natural, but I'm just amazed out how quickly these clumps seem to propel themselves upward from the bottom. How are they doing that? It doesn't happen that often so I've never been able to get a video of it yet, but it is quite interesting.

 

Damned sea-monkeys, always getting into your beer.

 

CO2 pockets trapped under yeast/break rafts.

Or an irish mouse.

 

I can only assume this is during fermentation? Yeast and other particles in the trub (proteins, hop material etc) will rise and fall as fermentation progresses. Until they all eventually fall out of the beer. I've never seen anything "jump", but definitely have seen them circulate through the beer. You sure it's the same piece of trub that's "jumping"? Grab a video next time you're checking the temps...

 

^^Definitely this!

 

Certain strains of yeast do that in my beers quite often. I have a beer that has been fermenting with Safale US05 for the last 12 days that is doing that a lot right now. I also see it happen (although less frequently than this batch) with Safale S33.

It's caused by CO2 carrying up yeast from the bottom. A lot of times the yeast in my carboys will make it all the way to the top and slowly sink back down leaving a little yeast "jet trail" behind it.

 

Yes... it is definitely the same piece that is rising and falling when I catch it happening. The CO2 from under the yeast cake makes some sense. I just never realized that it would rise with so much acceleration from the bottom. Those things come shooting up so fast when they do. It seems to rise so much faster than I would picture a normal air bubble rising in a liquid... especially if it has a hitch hiking clump of yeast in top of it... but maybe it is just a perception thing. I'll try and get it on video. The CO2 pockets from under the cake makes sense... the acceleration of those little boogers caught me off guard.

 

Sometimes I can see what looks something like boiling hops during fermentation if the beer is light enough. That's just how vigorous the fermentation is sometimes, the yeast are flying everywhere.

 

I have some S-04 fermenting at 64f in my IPA right that looks like a shaken snow globe right now.

 

[ame]https://www.youtube.com/watch?v=xm33934qM4E[/ame]

 

I've seen that movie before. The ending was kinda predictable...

 

US-05 is basically my sea monkeys. I video every fermentation. I'm crazy.