Is Underfloor Heating Killing my Yeast???

[puravida]

I just realised that the room I ferment in is also houses the controls and pipes for the underfloor heating we have in the kitchen.
The plus side is the small cupboard/room is always a constant 21 degrees but then the pipes run under the floor to get to the kitchen.

I'm wondering if the actual floor temp is warmer where the beer sits on it but it is very hard to accuratley measure.
Would it be possible that the heat under the floor is killing the yeast as it sinks even though the ambient temperature in the room is 21 C?

So I get 1-2 days of very active fermentation and then my beer recently has been sticking at 1020. One or two beers out of the past 6 have attenuated properly - maybe they were more tolerant strains?

I never used to have this issue but then my wife could had fiddled with the heating dials???

Make any sense? Or am I clutching at straws?

Would setting the buckets on a platform help?

 

[thejesmonddingo]

Get a sheet of this http://www.diy.com/search/polystyrene/J ... mm-9273748 and stand the FV's on it,so there's noadditional heat through the floor,cheap and easy.
Ian

 

[Dave1970]

If you have an air temp of 21C I can see 2 problems:

1. During the vigorous stages of fermentation heat is produced so you brew is likely to be well over 21...too hot!
2. As you suggest it does seem likely that if the air is at 21C then the floor is probably warmer

combine the 2 and it is very likely that you are getting some pretty high temps at the bottom of your FV, an insulating layer as suggested by JesmondDingo would help with problem 2, really a 21C cupboard is still a bit warm though

 

[puravida]

So you guys think that I may have correctly identified the stuck fermentation issue?
Is there anythign I can do to kick start two brews currently in there and stuck at 1020??

 

[Dave1970]

it depends how hot we're talking, normally I'd expect excess heat to cause off flavours rather than stuck brews, but I guess if you get hot enough it could reduce the vigor of your yeast...a good stir might get it going again with luck

 

[thejesmonddingo]

The other thing that springs to mind is how are you checking the cupboard temperature,as,like Dave,I'd be surprised if 21c was killing the yeast,but I got a cheapo digital thermometer off Ebay last week,that's given me some worryin g moments,until I calibrated it against a glass one,and realised it was reading 2 deg high.
Ian

 

[puravida]

IN all honesty - not very accurately.
I'm using one of those free kid's bedroom thermometers you get with 'gro-bags'
I do have a very accurate thermapen but it's ot very good at measuring air-temp. Needs to be stuck in something!