Mash Temp question with BIG RIS's

I am curious where everyones's thoughts are on mash temps with regards to big Russian Imperials...are lower mash temps, say 148 the norm because the beer will only ferment so low anyway, thus giving a sweet, chunky body? Also, if I wanted to get to 13%, which yeast would you go with? The last one I made, I used dry nottingham. Perhaps a yeast cake is truly the best option? I've heard of people using champagne yeast to finish it off, but I worry about how this would effect the overall beer.

EkieEgan said:

I am curious where everyones's thoughts are on mash temps with regards to big Russian Imperials...are lower mash temps, say 148 the norm because the beer will only ferment so low anyway, thus giving a sweet, chunky body? Also, if I wanted to get to 13%, which yeast would you go with? The last one I made, I used dry nottingham. Perhaps a yeast cake is truly the best option? I've heard of people using champagne yeast to finish it off, but I worry about how this would effect the overall beer.

Click to expand...

Ixnay on the champagne yeast: stick with beer yeast. If I were going after 13% I'd use S-05.

Yes on big beers it's normal to mash at a low temp for a longer time, 149F sounds about right, I'd do that for at least 90 minutes unless you're recirculating the mash. I've gone as low as 146F (on accident) for 2 hours on an Imperial stout it turned out great, not watery at all.

As for yeast I would go with san diego super yeast, big starter, you shouldn't need any other yeast.

Nottingham is an excellent choice; it has a high alcohol tolerance and will chew through so much sugar as to render the mash temp question moot.

So I did brew my RIS about 10 days ago. I mashed in at 149 and held that for 90 minutes then took almost 2 hours to sparge..long vorlauf then took my time. I didn't figure brewhouse efficiency, but I got a great gravity. I collected 7.5 gallons and boiled for 90 minutes and ended up with 1.121 Not bad! I ended up with 4.5 gallons of wort and that suited me just fine. The last RIS I tried, I ended up with more volume, but lost it out the blowoff tube. I did use US-05. I pitched 2 packets. Great fermentation..it's still going, but has slowed. Hopefully it drops into the 1.020's range. Somewhere in the 2's would be nice. I appreciate all the advice from all of you!!