Beer Temperature profile after FG reached

[WM7793]

Having been doing some research on the subject, it now seems that the best current practice is to leave the beer on the yeast after fermentation is complete, for up to 4 weeks or so, to allow the yeast to do its thing and clear up any nasties and to allow the beer to settle and clear on its own.

Now could the more experienced forum members advise me on what is the best current practice for the temperature to store the beer, following fermentation, and prior to bottling.

Is it:

1. Maintain fermentation temperature for this post fermentation period, ie around 19 degrees C?

2. Gradually reduce the temperature by a couple of degrees C every day to around 10 degrees C?

3. Or crash cool to around 10 degrees C, and maintain this temperature until bottling?

Your advice as always is very welcome,

ps, using a STC1000 and a fridge

Best regards,
WM7793

 

[robsan77]

Great question!

Not sure you'll get a conclusive answer though. Lots of differences out there. I personally have different protocols for different beers depending on malt profile, hop profile, abv and how patient I'm feeling.

 

[morethanworts]

My understanding is that the 'cleaning up' to which we often refer, is diacetyl (produced in the early stages) being 'eaten up' by the yeast in the latter stages, promoted by raising the temperature while the final few gravity points drop (rather than when fermentation has completely finished). A diacetyl rest, as it's called. I'm not sure that the yeast 'absorb' much, as such, once they've gone dormant. Of course, the beer also clears as the yeast and other particles fall, though I'm not sure that's what people mean by 'cleaning up'.

I'm going to give Chris White's Yeast book a good read after Christmas, to learn more - so maybe someone else can put me right for now if I'm wrong on that.

Personally, I tend to raise the temperature a few degrees for the last bit to make sure it's full attenuated (and perhaps to help with the diacetyl), then cool (8C and often below) promptly for a couple of days, rack prime and bottle. The worst esters that come about through fermenting at high temperatures do so at the start, while the yeast is dividing, so raising the temp a bit at the end is not a problem.

 

[ericmark]

Watching with interest for replies. I have small area of kitchen to house fermentors and a shed for the bottles the longer it stays in fermentor the less beer I have so time in the fermentors is rather important. When it has nearly stopped I swap fermentors as this then reduces the sediment in the bottles so around a week to 2 weeks in each fermentor depending on kitchen temperature and then bottled. My wife will normally allow bottles in kitchen for 5 days before forced to take to shed. Mainly bitter always from a kit.

I have noticed some batches still taste green after 3 months yet others seem OK after 3 weeks, and I am sure it's all down to kitchen and shed temperature. If kitchen is cold I do have a under floor heating demo tile around 12W which is enough to raise temperature by around 3 degrees but once in shed it's down to mother nature.

What I have found is my body warmers fit nicely around fermentor with air lock out of the neck and this seems to stabilize the temperature between day and night. Using these has vastly improved my beer so simple yet effective however means I have very few body warmers to wear. However the fermenting must release heat and if I get body warmer on early it seems to stay a degree or so above air temp.

In both directions I have noted it takes a long time for 40 pints to change temperature and the idea of a cupboard with a light bulb in the bottom to keep my beer a little warmer is something I have considered one worry is should it drop below -2 degs C it could freeze however at moment only option would be to leave the two 50W spot lights on in the shed.

 

[brewtim]

For English ale I keep mine at fermentation temp for around 7-14 days depending on style of beer and type of yeast and work/weekend schedule. Then cool to as cold as poss -2 to +2 depending on fridge for around a week then transfer to keg for carbonating then bottle.