Un-sticking a couple fermentations - what to do?

So the last 2 batches I got going, I decided to ferment at a nice cool temp. So I stuck 'em in the cold cellar with the door open. They've been hovering around 10-15*C for 10 days, and I just took a reading/sample.

The IPA is supposed to get down to 1.015, but it's at 1.020. Still appears to be some krausen happening though, so I'm assuming things are fine, just slow. I put it in a warmer spot (18-20*C).

The Porter though, is supposed to attenuate from 1.068 to 1.017. It's stuck at 1.030 and hasn't had any signs of fermentation for about a week or so. I moved it to the same 18-20*C environment, and stirred up the yeast cake a bit with a racking cane.

Here's what I'm wondering - was this enough to kick-start the yeast to get back to work? I have some of those pocket-warmer things lying around. Would it hurt anything to pop one open and stick it under the carboy wrapped in a facecloth? Would the concentrated bit of heat for 6 hours help things, hurt things, or make no difference whatsoever?

You know, like these things:

I would leave it in the warmer spot for a while and see if it finishes up on it's own.
I know a buddy had a similar issue he boiled some water dextrose mixture and pitch it in.

The simple sugars got the yeast to continue feeding, he didn't hit expected fg but got it down several points.

In addition to warming it up a bit, I've had good luck boiling a few tbsp of yeast (bakers, since I have a ton of it) for yeast nutrients along with a couple ounces of table sugar and adding that to the mix.

The yeast get working on the new simple sugars and are helped along with the boiled yeast for nutrients. I wouldn't expect it to get down to 1.017, but you might hit .020. It's worth a shot.

Then....since there is still activity, leave it alone. Fermentation slows down at lower temps. give the beasties some more time.

There is a good article on cold ale fermentations in Vol 34 #6 issue of Zymergy, the Nov/Dec 2011 edition.

Depending on the yeast you used and the temp. it work best at you may finish out fine just raising the outside temp.; check it in a week or so. Cheers:rockin:

Sooooo, the IPA is back in action bubbling away at a nice mellow clip. The porter though - no signs of life. Should I just leave it alone for a week and check the gravity again?

When a fermentation is getting itself un-stuck, does it take a while for the yeast to get set up before they start to party again, like an original pitch?

paulster2626 said:

Sooooo, the IPA is back in action bubbling away at a nice mellow clip. The porter though - no signs of life. Should I just leave it alone for a week and check the gravity again?

When a fermentation is getting itself un-stuck, does it take a while for the yeast to get set up before they start to party again, like an original pitch?

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Sometimes. But a 1.030 porter may be near its FG, depending on the ingredients.

Yooper said:

Sometimes. But a 1.030 porter may be near its FG, depending on the ingredients.

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Really? This is the "black pearl" recipe, and I did it all-grain. Hit the OG perfectly. So far all of my all-grain brews have hit the numbers bang-on (sometimes too much efficiency, had to add a bit of water), and have attenuated to the expected FG - once even a bit below.

1.068 OG, supposed to get down to 1.017. 6.68% ABV as opposed to the current %5. I think it needs this extra kick to warm it up a bit - it's quite bland right now.

Anyway thanks for the input - I'll just leave it for a week and see what's happening. As with most brews, the problems will probably just take care of themselves. The beer will do what it wants to do. No sense in forcing the issue. I'll drink it regardless!

paulster2626 said:

Really? This is the "black pearl" recipe, and I did it all-grain. Hit the OG perfectly. So far all of my all-grain brews have hit the numbers bang-on (sometimes too much efficiency, had to add a bit of water), and have attenuated to the expected FG - once even a bit below.

1.068 OG, supposed to get down to 1.017. 6.68% ABV as opposed to the current %5. I think it needs this extra kick to warm it up a bit - it's quite bland right now.

Anyway thanks for the input - I'll just leave it for a week and see what's happening. As with most brews, the problems will probably just take care of themselves. The beer will do what it wants to do. No sense in forcing the issue. I'll drink it regardless!

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What was your mash temp?

45 @ 158*
10 @ 175*

I use the old faithful Coleman Xtreme, which doesn't seem to lose any more than 1 degree in an hour. I check runoff temps with a little thermometer I've got, and they've always been pretty bang-on.

paulster2626 said:

45 @ 158*
10 @ 175*

I use the old faithful Coleman Xtreme, which doesn't seem to lose any more than 1 degree in an hour. I check runoff temps with a little thermometer I've got, and they've always been pretty bang-on.

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At 158, and maltodextrine and lactose added to the recipe (both unfermentables), you could very well be finished. I wouldn't get any lower than about 1.026 or so with that recipe at that mash temp, even with a more attenuative yeast.

Really - then all these cats in that thread have led me astray. Damn internets...

No problem - still needs to chill (as in sit there at room temp, not actually be cold) for a week or more anyway. Now I may have stirred up that yeast cake for nothing.

I will wait 6 more days, take another reading, and follow-up here with the results so the next guy searching can learn something.

THanks Yoops

Agreed that you may be done, or close to it. High mash temps + malto and lactose = lots of unfermentable sugars to raise your FG way up. Let us know how it turns out. Good luck!

I also agree that it was probably close to finishing SG.

You could try some EC-1118 champagne yeast to see if it can finish any further.

Could you post the full recipe and yeast strain please?

Next time check the yeast manufactures recommended temp range for primary fermentation.

Denny's Evil Concoctions said:

I also agree that it was probably close to finishing SG.

You could try some EC-1118 champagne yeast to see if it can finish any further.

Could you post the full recipe and yeast strain please?

Next time check the yeast manufactures recommended temp range for primary fermentation.

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Recipe is here, and it's popular:
https://www.homebrewtalk.com/f126/black-pearl-porter-ag-24243/

ALL GRAIN - 5 Gallons
8.00 lb Pale Malt (2 Row) US (2.0 SRM)
2.00 lb Munich Malt - 10L (10.0 SRM)
1.00 lb Caramel/Crystal Malt - 30L (30.0 SRM)
1.00 lb Chocolate Malt (350.0 SRM)
1.00 lb Oats, Flaked (1.0 SRM)

0.50 oz Fuggles [4.52%] (60 min)
0.50 oz Fuggles [4.20%] (2 min)

0.25 tsp Irish Moss (Boil 10.0 min)

1.00 cup Malto-Dextrine (Boil 20.0 min)
4.00 oz Lactose (Boil 15.0 min)

1 Pkgs London Ale (Wyeast Labs #1028)


Mash Schedule: Single Infusion, Full Body, Batch Sparge
Total Grain Weight: 13.00 lb
Mash In Add 4.06 gal of water at 170.5 F 158.0 F 45 min
Mash Out Add 2.50 gal of water at 206.7 F 175.0 F 15 min

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OG was 1.068, expected FG is 1.017.

Well, IPA dropped to 1.014 - awesome. Added dry hops yesterday.

I'm going to check the porter this weekend and bottle it if it's the same. I've just been leaving it alone since moving it to a warmer environment. Hoping for a pleasant surprise!

I am having a similar issue with an Irish Oatmeal Stout. After 9 days I was at 1.019 but my Mash Temp was a little high (157) and My OG was .002 higher than target. I raised the temp from 65 to 70 and in the last 3 days it moved down to 1.016. I am thinking this may be as low as it gets. I am going to let it set at 70 for 2 more days and then move it to a cooler temp for 2 weeks of conditioning.