I made a batch of braggot (~46% honey) a couple of weeks ago, and used the Duvel strain (a pack of Wyeast 1388 and a vial of WLP570). Pitched at 65 and ramped it up to 82 over the course of 7 days. Is there a good rule of thumb for how long the yeast should sit at the high temperature before I cool it, or is it best to just watch the gravity and wait until the yeast finishes?
-
Why did you heat it like that, and why did you let it get so warm? 82 is 2° out of the range for 1388 and 7° out of the range of the WLP570.– BrandonCommented Dec 10, 2010 at 16:08
-
1Because that's what I have seen recommended for the Belgian Golden Strong style, using that yeast. Zainasheff & Palmer recommend that temperature in Brewing Classic Styles, and similar temperatures are mentioned in Brew Like a Monk.– bakaCommented Dec 10, 2010 at 16:18
2 Answers
If the temperature schedule was intended for high attenuation and cleanup of yeast byproducts, such as diacetyl and acetaldehyde, then you should keep it at the warm temperature until a minimum of two days after terminal gravity has been reached.
If you fermented warm to produce more esters, fusels, and phenols, then you only need to keep the beer at the current temperature until terminal gravity is reached. Dropping it earlier will cause the yeast to slow, or even exhibit heat shock, and your fermentation may fall a point or two short of the lowest possible final gravity.
Also, just a warning - you're probably going to have excessive acetaldehyde from fermenting this warm - I would guess upwards of 300 ppm.
-
I did something similar with a Dubbel using 3787 this summer, and let it sit for a month at the upper 70's to low 80's, and it didn't have any noticeable acetaldehyde flavors. Though I really don't know what to expect with this amount of simple sugars. Ah well, every batch is an experiment.– bakaCommented Dec 10, 2010 at 18:54
-
Hmmm...maybe you won't, but I made a dubbel with 1388 and 2 lb of turbinado (along with 13lb of malts) and fermented in the 78-80 range and it wasn't drinkable for 18 months - it was a green apple bomb. Can you post a follow-up comment after tasting?– BrandonCommented Dec 10, 2010 at 20:11
-
Sure, I'll be glad to. This is my first time working with 1388 or 570, so who knows what's going to happen. :)– bakaCommented Dec 10, 2010 at 20:55
-
I dropped this braggot down to cellar temperatures (~55F) after putting it into secondary, and it's been slowly clearing up. I don't notice any acetaldehyde coming from it. It did contain a bit when the yeast were still in suspension, but I think the 3 weeks at the high temperature allowed them to clean up after themselves quite well.– bakaCommented Jan 7, 2011 at 16:21
Since you're making a braggot, I don't think the "traditional" rules apply. Being a few degrees out of the recommended temp range isn't gonna be a big deal. While I'd never ferment a beer anywhere near that warm, you might be just fine for a braggot.