Clearing in the warm...

[UpTheToon]

I brewed a black IPA just before Christmas. I used a little bit of gelatin for the first time after fermentation and cooling in the FV. I left it for a day or 2 then bottled and put it in my ferm fridge... all except 3 bottles which wouldn't fit so I just put them out the way in the dining room where its mostly pretty warm but cool at night.

After a week the fridge bottles were all carbed up (remarkably quickly I thought but hey-ho) so since then they have been in the garage (pretty cold) to clear.

I don't know if its because this is my first black beer I've done (so its more noticeable) or an effect of the gelatin but the beer has quite a few white flaky floaters which I thought would clear down to the bottom after a while in the cold. They don't seem to be. Even with careful pouring there are still some suspended bits.

At the weekend I found one of the three bottles that have been in the dining room and stuck it in the fridge for a few hours... it was clear as a whistle! The head was better too.

This seems to be against all that I've read about clearing beer at colder temperatures... can anyone explain to a simple inexperienced AG'er like myself?!

[Charles1968]

The reason beer is cloudy while it's fermenting is that CO2 bubbles are rising in it, which lifts sediment (and creates foam, i.e. Krausen, when fermentation is most active). Anything that stops CO2 bubbles will stop the liquid moving and will allow turbidity to drop out. When you chill beer it suppresses fermentation and makes CO2 more soluble, so bubbles stop rising and the beer clears. When you bottle beer, it puts it under pressure and prevents CO2 from coming out of solution, so bubbles stop forming and the beer clears. Beer will also clear naturally without pressure or chillling if you simply let fermentation run its course and then wait for it to de-gas. You don't need to chill it to make it clear. Once you've bottled your beer, chilled and nonchilled should clear at exactly the same rate.

[Jim]

There's some good information on yeast flocculation (it's all right, they can't touch you for it ) in this Wyeast article.

Temperature:
Lab trials have found that brewing strains have different optimum flocculation temperatures
Flocculation for one lager strain increased from 41°F to 77°F
One trial showed flocculation of lager strains was optimal at 50°F and decreased significantly below 41°F
In other strains tested, flocculation was repressed at 77°F and optimal at 41°F
This is obviously very strain dependent. Good record keeping will help to determine the optimum temperature range for your strain.

[UpTheToon]

Cheers guys. Ill have a read up on that link Jim...