WLP002 diacetyl rest

[Goulders]

Did BIAB#2, viewtopic.php?f=35&t=46600 GW's London Pride over the weekend. I no chill in a cube which allows me to split the brew day and to pitch yeast when I am ready. Worked form my first BIAB (SNPA clone) which is going down very well!

So my question is regarding the diacetyl rest. I don't have a controlled temp fridge.

My thoughts are pitch around 18C(temp of my utility room) for about 3 days, then bring inside to raise temp to 20-21C for a couple of days and then back into utility room for another week to let the yeast clean up.

Does this sound right?

Thanks
Jon

[Eric]

If you are fermenting at 18C ambient, I doubt you need consider any rest period. I'd be inclined to leave it for 5 days then put it somewhere cooler for a day or two then cask it and return it to the utility. WLP002 will drop out quite quickly and you could be drinking it at New Year.
You said you were going to use half in a 1 litre starter but it read as if you hadn't started this. I believe those yeasts are sufficient for 5 US gallons, ie 20 litre brews and if you are just pitching half you will likely find it will take 2 or 3 days to get started.

[Hogarth]

It depends how much diacetyl you like in your London Pride. I brewed one once with WLP002, fermenting it at 19°C and racking to barrel after five days. Complete disaster. The diacetyl was overpowering. If I were you, I'd wait for the fermentation to finish then bring it inside for a few days, then carry on as usual.

[Goulders]

Thanks for the replies. As for the starter, I will pitch the vial into 2l or 1040 LDME and then when fermented, pitch 1l into the FV and keep 1l in the fridge to step up and split again for another brew.

Haven't made the starter yet, but the beer is in a "no chill cube" and will pitch when ready, probably at the weekend the way things are going

[Eric]

It depends how much diacetyl you like in your London Pride. I brewed one once with WLP002, fermenting it at 19°C and racking to barrel after five days. Complete disaster. The diacetyl was overpowering. If I were you, I'd wait for the fermentation to finish then bring it inside for a few days, then carry on as usual.

That's a fair point Hogarth, only once can I remember a buttery taste in my beer, that's not to say that only once has my beer contained diacetyl, I've made some pretty horrible brews in 50 years and most of the worst ones were those I'd care to forget from the dim distant past. However, your comments surprised me as 19C is optimal for WLP002 which would normally ferment out in 2 to 3 days leaving a similar period to clear the circa 200ppb diacetyl to be expected.

Living in the North East there aren't too many periods when high temperatures cause problems brewing, cold is the greater enemy here. So each to his own I suppose, as C.J. would have said, "I didn't get where I am today worrying about diacetyl".

Cheers.

[Goulders]

Fermentation has finished on this one, and down to 1008 from 1038. Had a taste, and quite smooth in the mouth with maybe a slight buttery taste but not too bad. I did a diacetyl force test and tasted watery so no concerns that diacetyl will be there if I rack it.

Should I bring inside and leave for a coule of more days and then put outside to chill clear?

Would like to get this one kegged/bottled soon. The yeast was pitched about 2 weeks ago, and I guess fermented out to 1008 about 4 days ago or so.

[simple one]

I find that WLP002 needs to be overpitched and well oxygenated to ensure low diacetyl levels.

[Goulders]

Thanks. I pitched a 2l starter into 27l and was well oxygenated. It isn't a butterscotch taste others mention - maybe it's ok. Perhaps I'll leave for a couple of more days before putting outside (8.5 deg [ish]) for a day to clear.

[Hogarth]

Often you won't taste diacetyl at this stage, but it may form later from tasteless precursors that are already in the beer. So a couple more days is definitely a good idea.