Exposing Fermentation

[seand]

I'm on my third brew. I use a plastic bucket primary, so I've never really seen what's happening on the inside. In other words... noob.

This time I used the sample for original gravity in a glass and I added the tiny bit of left over liquid yeast.

It's been very interesting so far! CO2 bubbles started appearing very quickly and within hours the yeast had visibly multipled by 10x or more. There apparently isn't enough CO2 to create much pressure... but it's a surprising amount of activity with much more CO2 bubbling than from a carbonated drink. The real fermenter airlock isn't bubbling. Presumptively it's just as active (or more!) since it started with much more yeast.

Without popping the lid of the real fermenter... seems like good evidence that there can indeed be much more going on than your airlock would indicate.

It's been a fun experiment so far using things that would have ended up down the drain.

 

[jester5120]

I've been brewing for about 5 years and I always use a glass or plasatic carboy so i can watch what's going on. It's absolutely crazy to see how much activity is going on there. I take pictures and videos of it sometimes. Believe me you're not alone in your fascination with it, i think we're all like that

 

[aubiecat]

I only have 3 brews under my belt but I have already purchased and used a 6.5 gal. carboy because I couldn't stand it. I had to see what was going on in there. I hate that I didn't have it in time for my belgian trappist w/ the Wyeast trappist 3787. That stuff almost blew the top off my bucket. Would have loved to seen it form inside. There WILL be more opportunities.

 

[Captain Damage]

Watching a fermenting carboy is hypnotic. Like the most extreme lava lamp ever!

 

[RM-MN]

Bunch of voyeurs I'd say. Don'tcha know that the yeast are propagating in there and probably want a little privacy? I'll bet you don't live in a glass house.

You could use some saran wrap on top of your bucket for a few days so you can see what is going on in there. Once the ferment slows, put the proper lid on to keep it more sanitary.

 

[jester5120]

Do a wheat beer with open fermentation. Don't put a lid on it at all for a few days

 

[seand]

Good to know I'm not the only one.

After about 16 hours it's somewhat dull in comparison to the beginning. It did blow the top off overnight that was rubberbanded on. The real fermenter is bubbling away as well. Much of the yeast that was on the bottom is now on the top and there are circulation zones and continuous bubbling vents on the "sea floor"... pretty cool.

 

[seand]

At some time yesterday the top layer and most of the krausen fell to the bottom in the experiment. This morning, there's a very distinct layer of suspended particles about 1/10th of an inch from the surface. What little CO2 bubbles that are still rising don't interact with the layer or disturb it at all.

It makes me think there must be a second liquid at different density that has separated out at the top. But I have no idea what yeasts produce that would behave like that and wouldn't be water soluble?

It's followed the real fermenter in activity pretty closely even though it's 15 degrees warmer (63 versus 78). That was surprising. I can't detect any difference in fermentation odors. A taste test is probably invalid since it's been exposed to light the entire time.

 

[Mase]

Pretty neat experiment!

I don'y own any carboys, I've always read they can be a PITA to clean and transfer from. But I'm thinking if I ever do small test batches I'd like to pick up a 3 gallon carboy.

Also cheers fellow Floridian!

 

[RM-MN]

At some time yesterday the top layer and most of the krausen fell to the bottom in the experiment. This morning, there's a very distinct layer of suspended particles about 1/10th of an inch from the surface. What little CO2 bubbles that are still rising don't interact with the layer or disturb it at all.

It makes me think there must be a second liquid at different density that has separated out at the top. But I have no idea what yeasts produce that would behave like that and wouldn't be water soluble?

It's followed the real fermenter in activity pretty closely even though it's 15 degrees warmer (63 versus 78). That was surprising. I can't detect any difference in fermentation odors. A taste test is probably invalid since it's been exposed to light the entire time.

When the fermentation slows down the yeast tends to clump up and begin to settle out. Since the yeast aren't much more dense than the beer they settle very slowly. That's why you see the clearer liquid at the top, it simply has much less yeast. Over the next few days you should see that layer get bigger, extending down the column until the whole thing is very clear.

 

[seand]

I measured the gravity of the experiment today... it's on the recipe final on the dot. CO2 activity is essentially zero. The real fermenter has stopped as well.

I absolutely see the yeast suspension differentiation... it's highly transparent at the top and the transition line to cloudy is lowering with time. The suspension layer is still there though above that though. This particular brew had fresh orange peel and corriander and I wonder if some of those ingredients are forming oils in a top layer?

My wife today said we should do this for future brews... she's just as hooked.

 

[RM-MN]

While that is a nice way to see what is going on in the bucket you need to be aware that the two fermentations do not necessarily work at the same pace. Also what you don't see is the complex chemical reactions that are going on and will continue to go on for some time as the compounds that the yeast produced during the fast initial ferment are slowly broken down into compounds that we find more pleasing to the palate. Since these go on slowly and do not produce CO2 they are hard to see.

 

[seand]

While the CO2 output appeared about the same pace, there are definitely some big differences. I cracked open the real fermenter today to do a gravity measurement and it has a huge krausen layer with large foam bubbles on top... so I closed it back up untouched.

So I'm in the dark on what the gravity is. The experiment is basically finished and completely settled out. Between smaller volume, column height, temperature, light, who knows what variables drove that.

 

[Teromous]

Dry-hopping gives some interesting eye-candy as well. I just had one where pockets of CO2 would shoot up through the layer of fallen hop crud, and shoot it straight up into the wort. It was like watching the intro to Blade Runner with green glasses on.