Yeast Harvesting Gone Bad.......Sorta.

[seabush]

So I made an all grain Kolsch kit from NB using US-05 after a week of good fermentation at 64 deg. and 48 hours sitting at 1.012, I figured primary was done.

<side note, the last 2 batches of IPA and IIPA I made with US-05 fermented down to 1.001. and 1.000. I didn't think that was possible!>

I have never harvested yeast before and wanted to give it a shot since I have a conical with a mason jar for this reason. I pulled the jar and transferred it into a quart size mason jar to start the yeast cleaning. I think I may have pulled it before it was done fermenting. As you can see in the pictures, while transferring to the larger mason jar, there where a lot of foaming and bubbling taking place. By the time i transferred most of it, there was more volume in the larger jar, including all the spillage, then was in the original jar. At this point i figured these little buggers still had some fight left in them, so i tossed them back in the fermenter. I guess we'll see what happens. Thoughts? Comments?

BTW, should I have posted this to an established thread? Or is that "hijacking"? I don't know the proper etiquette.

 

[doomy86]

Why did you put them back in the fermentor? You probably just added a soup of contaminated and dead yeast cells.

 

[seabush]

Well my thought process was since they were still bubbling, they were still alive and active. And I think I was pretty sanitary with all my transfers.

 

[ericbw]

A week might be long enough to finish the initial fermentation, but maybe not. Especially if you dropped it to 48 degrees, where it would have a hard time finishing if it had to.

But I think you've accidentally given another clue about what's going on: Getting an IIPA down to 1.000 seems not only unlikely (because that would mean no residual sugars), but also bad. There would be not malt balance to offset the hops or alcohol, so you'd end up with something thin, harsh, and bitter. An IPA or IIPA should be smooth, malty, bitter, and hoppy on the nose.

Either: you have something fermenting all the sugars (usually that's bacteria, but it could be some kind of yeast that works on those long chain sugars), so it's fermenting out more than US-05 could be expected to OR you're not taking accurate hydrometer readings, and the actual gravity is higher than what you're seeing.

What should the IIPA have finished at? 1.014? If you got 1.000, then your reading could be off by 10 points, or maybe even a little more.

If that's the case, then your 1.012 Kolsch might really be 1.022 or a little more, which wouldn't be finished.

Are you checking the final gravity with a hydrometer or with a refractometer? If it's a hydrometer, are you correcting for temperature?

 

[SlitheryDee]

I think I would expect a little foaming just from the agitation of transferring causing co2 to bubble out of solution and general aeration. As far as the yeast still being "alive", of course they're alive. That's why it's worthwhile to harvest them. Any kind of visible activity has to take a back seat to whatever your hydrometer tells you. If your readings are stable and within a few points of your expected final gravity then you're done no matter how much the yeast foams when you harvest it.

If I was getting a very low gravity reading like you are I think I would be looking to find a second device for testing gravity just to error check the first one. Alternatively you could try the hydrometer you have with a bit of distilled water to make sure it's getting an accurate reading. If you get anything but 1.000 on distilled water then you need a new hydrometer. My first hydrometer was off by a few points as well, which almost caused me to prematurely bottle that batch.

 

[passedpawn]

Posting in another thread would be hijaaking unless it was thread created for the purpose of hearing other peoples stories.

Never throw anything back into a fermentor if you can avoid it. In this case, I see no reason to have done so.

My ale fermentations are usually done in about a week, but I let them go 10 days anyway. I normally don't even measure the gravity until that time. I'd guess the bubbling you saw was just dissolved CO2 coming out of solution due to the agitation and increased temperature. Regardless, you should have just left the yeast in the jar and made sure the jar was not sealed. Though you dumped the yeast on the bottom of the conical, there's still a ton left in suspension in there.

I use pickle pipes (search amazon for that) as mason jar lids for yeast in my fridge.

 

[seabush]

Thanks for all the replies. I think I'll give it a few more days at a stable FG. Then kick it up to 70 to play some clean up. I suppose all the damage has already been done.