Diacetyl rest

[NewkyBrown]

My last three batches have had excessive amount of diacetyl so I am now paranoid about the batch I have fermenting now!

I brewed an ale on Friday night and the fermenter has been in a cooler at 64F since. At what point should I increase the temp? I've heard that it should be after 75% attenuated but how do I know for sure when this is? Also what temp should I try and raise it to?
I used 1056 with a 1 litre starter but no stir plate.
Thanks.

 

[osagedr]

My last three batches have had excessive amount of diacetyl so I am now paranoid about the batch I have fermenting now!

I brewed an ale on Friday night and the fermenter has been in a cooler at 64F since. At what point should I increase the temp? I've heard that it should be after 75% attenuated but how do I know for sure when this is? Also what temp should I try and raise it to?
I used 1056 with a 1 litre starter but no stir plate.
Thanks.

If you are pitching enough healthy yeast, diacetyl should not be a problem with most (but not all!) ale strains; the only ale strain I ever had diacetyl with was a super-flocculant British strain when I racked out of the primary a bit too soon. You certainly don't need a d-rest with 1056 at 64 degrees (as an aside, most people who know that strain would tell you to ferment it around 70 as it can develop peachy esters in the low 60s).

I would take a careful look at your process to see where your diacetyl problem might be coming from. Try searching on the internet and in this forum for "What causes diacetyl?" or similar to get started. Good luck!

 

[NewkyBrown]

Thanks for the reply.


I probably did under pitch the last couple of batches which I certainly won't do again! Hopefully this one will be ok. I will raise the temp for the rest of the fermentation to about 68-70 now. Until I get a freezer to control temps correctly I would rather play it safe and keep them on the cooler side.
Now to make a stir plate...