Brewferm Abdij - stuck fermentation.

[JohnRB]

With 500g of dark candi sugar I hit target OG of 1071. Rehydrated the yeast at 26degC and pitched it at 19degC.

Vigorous fermentation kicked off within 12 hours and finished within 3 days. Fermentation temperature was held steady at 19degC.

After 5 days (this morning) I had a present gravity of 1030 against a FG target of 1010. I have roused the yeast but, if this doesn't work, I'll pitch a rehydrated sachet of SafBrew T58. The question is should I re-aerate the wort and risk infection or not aerate and risk starving the yeast of oxygen?

Thoughts would be appreciated. Thanks.

John.

[Robwalkeragain]

Yeast will scavange oxygen after the ferment, so assuming it gets going again oxygen won't cause any oxidizing, and with a big gravity beer, adding oxygen is usually worthwhile. Can't see any issues but tbh t-58 will probably chew it dry regardless.

[JohnRB]

Hi Rob,
Thanks for the quick reply.
My concern with re-aerating isn't so much oxidation, which I agree shouldn't be a masjor problem, but infection from whatever bugs are in the air.

[wanus]

Hello John.
I just had the same scenario as yourself.A good stir with a sterilised plastic paddle got mine goin again.
It got down to 1.010 and i have just this minute finished bottling.
I now always pitch these kits at 24c.Iff yer have a heat pad or belt or FTH try getting yer temperature up towards 24c before stirring.
Thats what i would do.Good luck.

[sandimas]

Brewferm instructions recommend fermenting at 25C (yes, higher than I would have thought) so maybe 19C was a bit low for it?

[JohnRB]

Brewferm instructions recommend fermenting at 25C (yes, higher than I would have thought) so maybe 19C was a bit low for it?

Well that made me re-read the intructions but all is well!
The 25C refers to the temperature for re-hydrating the yeast prior to pitching. The instructions then say that fermentation should be in the range 18-23C which is a relief.
Thanks for your interest.

[JohnRB]

Update:
The present gravity is now 1012 and could drop further.
I got the fermentation re-started by tipping out the CO2 (heavier than air) and vigourously aerating. A taste this morning sugests, fingers crossed, that I've not introduced an infection.I'll leave well alone until early next week when it should be due for bottling.
Thanks to all for advice.

[WalesAles]

John,
How do you `tip out` CO2?
New one for me!

WA

[JohnRB]

John,
How do you `tip out` CO2?
New one for me!

WA

Good question!

CO2's heavier than air so if you tilt the fermenter a lot of it will flow out to be replaced by air. Do this a number of times and the the CO2 will be significantly diluted. More importantly this gas will contain a lot more oxygen than the 'pure' CO2 in the headspace which was what I wanted for re-aerating the wort.

[WalesAles]

John,
I will try hovering my syphon tube 10mm above the beer and suck out the CO2,
if the tube outside the FV is below the beer level, it will just be like siphoning petrol
when I was a kid!
We`ll see.

WA

[darrellm]

The 25C refers to the temperature for re-hydrating the yeast prior to pitching. The instructions then say that fermentation should be in the range 18-23C which is a relief.

I must have a different set of instructions - mine clearly say "stand the fermentor in a warm place (25C) and let ferment for about 10 days". I have these instructions saved as a .PDF, they may have updated them.

Glad you got it sorted, I usually ferment mine warmer than I'd do other beers and it usually comes out great. Looking at my records, most finish at 1012 but I occasionally get one to go down to 1010.

[JohnRB]

I must have a different set of instructions - mine clearly say "stand the fermentor in a warm place (25C) and let ferment for about 10 days". I have these instructions saved as a .PDF, they may have updated them.

Interesting! Looks like two completely different sets of instructions.

Makes me wonder, though, if I'd fermemented at a higher temperature if the fermentation would have stuck. Bit of a dilema for the next brew.

[sandimas]

I've heard before that there are different instructions about. Personally, I do ferment these on the warm side whereas everything else gets fermented 18-20C.

Just had my last bottle of Abdij this lunchtime - brewed 2 years, 3months ago! It was very nice.