Chocolate Foreign Extra Stout Fermentation Question...

[CarlosHernandez]

Fermenting a foreign extra stout (OG 1.072) at 67 deg using an Irish yeast. Plan on doing a d-rest at day 4 or 5. 10-14 days is usually enough to fully attenuate an ale, however I now am second guessing myself after reading Palmer's book. He mentioned somewhere that 3 weeks in primary wouldn't hurt high gravity beers or even some stouts. Should I leave it in there an extra week, or do you guys think two weeks is plenty?

[BarefootLion]

Ferment until its finished.
What's the SG now? What was your target FG? How vigorous was the ferment?

I tried to do my normal schedule on a Wit my bro brewed, for some reason his 1.045 took 3 weeks to finish the yeast just weren't in the mood. Unfortunatley its a natural product that doesnt always work on our schedules.

[MikeB]

It's great to have a plan going into a fermentation, but don't ever blindly go about it. Watch what is going on, and react as necessary. If your yeast strain is prone to throwing diacetyl, raise the temp while the yeast is still fairly active. This may be at day 4 or 5, but could be on day 10. I suspect that the Irish ale yeast you are using is not going to produce much DA. What raising the temp at the end of fermentation might get you is a little more attenuation. Big beers like the one you describe can tolerate sitting on a yeast cake for 3 weeks with no problem.

[CarlosHernandez]

Hey Mike,

So how would I know if it is day 4 or 5, or even day 10?

[MikeB]

If you are familiar with the different stages of fermentation the stage where you typically do a d-rest is late krausen. Late krausen occurs, not surprisingly, after high krausen. High krausen is when the yeast is usually at its peak of fermentation - most bubbles coming from an airlock, high point of froth on a carboy, etc... Once you see that the beer is past high krausen and the fermentation is starting to slow down, this is when you'll want to start thinking about doing a d-rest.

[CarlosHernandez]

You mentioned that the Irish yeast I was using, would probably not need a d-rest. I thought English yeast could benefit from a DA rest. Just wondering.