Fermentation Trouble

[Mayo]

Hi

I am currently having trouble with my 4th AG brew. My oatmeal stout has a stuck ferment and I need some advice.

Heres the grain bill -

Recipe Specifications
--------------------------
Batch Size: 18.00 L
Boil Size: 21.68 L
Estimated OG: 1.070 SG
Estimated Color: 83.9 EBC
Estimated IBU: 31.2 IBU
Brewhouse Efficiency: 70.00 %
Boil Time: 90 Minutes

Ingredients:
------------
Amount Item Type % or IBU
4.26 kg Pale Malt, Traditional Ale (Joe White) (5.Grain 72.82 %
0.45 kg Oats, Flaked (2.0 EBC) Grain 7.69 %
0.34 kg Amber Malt (100.0 EBC) Grain 5.81 %
0.34 kg Chocolate Malt (700.0 EBC) Grain 5.81 %
0.23 kg Crystal Malt, Medium (150.0 EBC) Grain 3.93 %
0.23 kg Roasted Barley (1000.0 EBC) Grain 3.93 %
55.00 gm Goldings, East Kent [4.80 %] (60 min) Hops 31.2 IBU
1 Pkgs London ESB Ale (Wyeast Labs #1968) Yeast-Ale


Its taken from Brewing Classic Styles.

Now, my OG was 1.064, and I had a 1lt starter of #1968 (maybe to small a starter?[I use a stir-plate]), but my fermentation stopped dead at 1.030. So i shook the fermenter a bit to suspend the yeast and raised the temp to 22 to see if any more activity would occur. No luck.

Im not sure what to do. The only option i can think of is pitching some US05 that i have hanging around just to finish the job. But thats a shame cause i was planning on using the yeast cake for my next batch.

Would the 1968 be completely dead? Or just be dormant for some reason? This is the first time this has happend.

Any help would be appreciated. Cheers.

 

[drtomc]

If you have a spare fermenter you could rack it and repitch. That assumes that the 1968 has just gone dormant on you, and will wake with fresh wort.

T.

 

[jjeffrey]

what temp did you start at? Was it constant, or did it cycle in the garage?

did you oxygenate your wort?

1968 is a top cropping yeast that is really cuddly- it drops out really easily. In my experience, to keep this yeast afloat you have to have plenty of oxygen in both starter and brew to start off with, you have to start a little warmer- 20 to 21, and you have to keep the temperature constant. A cold night will cause it to drop out. You really need to keep it above 18 at all costs.

My understanding is 1968 came from breweries in london that used union systems. The Burton union system tends to allow a bit of oxygen back into the brew during fermentation because of the yeast collection system which is open to air. This in turn ensures good cell walls for the yeast, as well as an extended growth period- essential if you want to keep it suspended. Also, the BU system constantly transfers fresh yeast back to the "fermenters" (unions). A yeast developed with a lack of evolutionary pressures to perform does need to have the whip cracked occasionally.

A stout is fairly forgiving on post oxygenation. I'd shake it up, then tip the lot (roughly, so you get a bit of air in) into another vessel. I've done this once before in the same circumstances, to good effect. I always keep some saf ale 04 on hand whenever I'm using the london series from wyeast- for this very reason.

Considering the % of special grains and the yeast, don't expect it to get far below 1.020. I reckon you'd be doing pretty good to hit 18.

jj.

PS- Jamil is not a god.

 

[jjeffrey]

:icon_offtopic:
HAHAHA- A Mobius sword! Nice.

 

[Mayo]

what temp did you start at? Was it constant, or did it cycle in the garage?

did you oxygenate your wort?

1968 is a top cropping yeast that is really cuddly- it drops out really easily. In my experience, to keep this yeast afloat you have to have plenty of oxygen in both starter and brew to start off with, you have to start a little warmer- 20 to 21, and you have to keep the temperature constant. A cold night will cause it to drop out. You really need to keep it above 18 at all costs.

My understanding is 1968 came from breweries in london that used union systems. The Burton union system tends to allow a bit of oxygen back into the brew during fermentation because of the yeast collection system which is open to air. This in turn ensures good cell walls for the yeast, as well as an extended growth period- essential if you want to keep it suspended.

A stout is fairly forgiving on post oxygenation. I'd shake it up, then tip the lot (roughly, so you get a bit of air in) into another vessel. I've done this once before in the same circumstances, to good effect. I always keep some saf ale 04 on hand whenever I'm using the london series from wyeast- for this very reason.

Considering the % of special grains and the yeast, don't expect it to get far below 1.020. I reckon you'd be doing pretty good to hit 18.

jj.

PS- Jamil is not a god.

Hey dude, thanks.

I know im not going to get it to drop to far, but 1030 is ridiculous. I started ferment at 20 degress, and it stayed at 20. Its in a temp controlled fridge. Iv never used this yeast befor but the starter did look very flocculent.

I may try shaking it up and dumping into a new fermenter. See if that works. I didnt oxegynate the wort, only the starter. Ill definately have to pitch more of this stuff in the future than a 1LT starter.

Thanks again.

PS- Who said he was a god?

 

[jjeffrey]

you didn't, but many have.

 

[Screwtop]

Feed it 15g of Nottingham and forget it for a five days......easy

Screwy

 

[Jye]

+1 on the repitching.

Ive just kegged an imperial porter which went from 1.102 to 1.040 and I wanted it to get to at least 1.030. So at the moment Ive got an IPA fermenting with Nottingham and Ill top crop some of the super yeast and chuck that into the keg.

The important thing with repitching it to pitch active yeast, do not just chuck another packed in.

 

[Bribie G]

I've used a couple of highly flocculating yeasts, the 1469 and the Ringwood. Both are Yorkshire yeasts and in trying to emulate the 'stone square' system I have thrashed them twice a day to oxygenate them and force the yeast back into suspension. I use one of those stainless steel flat paddle things with a circular plate on the end with lots of holes in that you use to fish stuff out of deep fry. Reject shop about five bucks.

I would imagine that any yeast from the Burton Union System would need similar treatment. If the gravity is still stuck at 1030 then I would personally give it a good rousing to get the yeast into suspension and as much oxygen back into the wort as possible.

If the gravity was a lot lower I would be reluctant to do that in case of oxygenation but with the gravity you mention, I reckon you should be safe. If no activity after a day or so then go the US-05 or Notto. My 2c.