Restarted fermentation

[Clint]

Hello all
Last week I moved a brew from the brew fridge that had nearly two weeks in there,to get a fresh brew in. I placed the first alongside on the garage work top on a heat pad controlled to 19. It looks like it's started fermentation again and has built up quite a lot of lid pressure and will bubble a lot of I move the blow off tube. I tested the fg last week and it was 1008 which is lower than the CML ale yeast usually goes. The sample was clear and tastes fine. The brew is an AG pale. I'm busy ATM but will test it again later....

 

[terrym]

Do you use CML Real Ale yeast?
I have an extract bitter on the go at present with this yeast, (not used it before), and used a packet for 16.5 litres.
It started at OG 1.039 and went really quickly for 2 days then slowed up and at day 4 the airlock is very slowly bubbling away but the SG is only 1.012. Is this about right?

 

[Oneflewover]

Not just c02 coming out of solution? Was it previously at a lower temperature?

 

[Clint]

It probably dropped after taking out of the fridge until the heater brought it back and stabilised it. It reads 18-19 now. Just seems a lot of gas this far in. The bitter in the fridge has zero head pressure now after nearly a fortnight.

 

[Slid]

Sounds perfectly normal to me - just moving a fermenting beer can nudge some active yeast back into contact with the wort. Fermentation goes on for a long time, even in cool temps. You notice this if you store the slurry from a previous brew in PET bottles in a domestic fridge for a few weeks. On re-use it sort of explodes out of the bottle on opening.

 

[Clint]

Terrym yes...CML ale starts off like the clappers then slows down. I find fg wise they're done in less than a week but I always leave at least two. This one has gone lower than usual too...I'll check it when I get back.

 

[Clint]

Update....this is still producing pressure and I just measured the fg ...1005.
It's also had exactly a month in the fv....it is quite clear though and tastes fine.

 

[cushyno]

Could it be that the heat pad supplies more direct heat to the base of the FV as radiated heat? The flocculated yeast may be locally getting higher temperature than the rest of the FV. In a brew fridge where it is the gentler and more gradual heating effect of the air, there wouldn't be hot spots anywhere in the FV.

The heat pad may be causing rousing too by creating a convection current inside the FV.

Does the heat pad have a separate temperature probe or internally controlled? If separate probe the above is highly likely until the FV temperature stabilises. If internal it may not be calibrated the same as your fridge temp control (STC/inkbird) so may be heating more than anticipated.

 

[Clint]

I recon this may be it...so what now?