RIS recipe help pls

[eyebrau]

Need some input on an imperial stout done friends and I are brewing. We have access to a bourbon barrel, so we are getting together to brew 12 gallons in two brew sessions of 6 gallons each. Using iBrew to plan, and I'm having concern about what the FG calculated out to be. I know for big brews the FG calculations can be hit or miss, especially on an all grain recipe.

Here's the grain bill for each 6gal batch:
20lbs 2-row
.5lb chocolate malt
.5lb roasted barley
.25lb black patent
1lb rolled oats
Late addition:
3lbs cane sugar
1lb brown sugar

Sugar additions are to help dry it out. Plan on mashing at 148F for at least an hour, and to fit my m/l tun, I'm at 1qt/lb. plan on using 2 packets of dry yeast in each, because I've had great experiences with it. Probably US-05.

Calculations have me with a FG of 1.032, which is excessively high... Thoughts? With the cane sugars and low mash temp, plus high attenuating yeast, shouldn't it get lower? Does the recipe look ok? For hops it'll be a single addition of summit to get to 80 IBU or so.

Help?

 

[eyebrau]

Actually, another thought that I'd like to run past you all for a thought... The two batches will actually be brewed a week apart (exactly). Assuming the first still has a rolling fermentation at second brew day, what are thoughts on krausening the second batch by pitching some of the active beer from the first batch in with the second?

 

[eyebrau]

Ok, so how about I ask this a different way. I recalculated manually using 70% Brewhouse efficiency and 75% attenuation, but for the cane sugars I used 100% efficiency and attenuation... Am I doing that correctly? Doing that I got a FG calculation of 1.026, which is more reasonable. Yes?

 

[eyebrau]

Used 22 lbs 2row rather than 20 for that calc.

 

[solbes]

I've brewed just one RIS. It was a 1.105 OG that finished around 1.029 initially in primary after 5 weeks. I racked to secondary. I pitched a 1.5L strong starter that was actively fermenting and it dropped it all the way into the low 1.010's. So, I think that part worked really well even though it was not initially planned. I used Bells yeast by the way and pitched onto an entire yeast cake from a previous mid gravity porter. Even with proper yeast counts, getting low enough can be a challenge. Mashing at lower temps like you have is key as well.

I did not use any sugar, and I caution you to consider if you really want 4 lbs of simple sugars in an RIS. No more than a pound per batch, or none if you ask me. Another tip, Maris Otter makes a great base malt for RIS, even if its only half your base malt bill. Special B can also be a great addition in 1/4 or 1/2 lb amount.

Jeaulous of the bourbon barrel, I used oak cubes soaked in bourbon. Total time in contact was 7 weeks and I have a nice vanilla note after 10 months from brew date. Give it a lot of time in seconary (or barrel). No rush. Mine just smoothed out after 9 months or so and continues to improve.

 

[dcp27]

Agreed with Solbes, 4lbs of sugar is too much in a RIS. rest of the recipe looks fine

Is this only a 10gal barrel? If so, be wary of the smaller barrels. Theres alot more surface area in a 10gal vs 55gal barrel so you'll get more oak/bourbon quicker. Also, is it a fresh bourbon barrel, or was beer in it first?

 

[eyebrau]

Yea, reformulating my recipe on the sugars. Thanks for the input there. Am I right on the calculations? I mean, do the software programs usually apply efficiency and attenuation percentages to simple sugars, even though they really should both be 100%?

it's a 55gal barrel. And yes, it's a fresh bourbon barrel.