Wednesday, March 11, 2009

Scottish Imperial Stout

My first Imperial Stout was the Old Rasputin Clone. I followed the recipe very close, and the stats came out perfect. After trying it side by side with the commercial beer, there were some elements missing. Mainly, the level of roast and hop flavor were lacking. It was a fantastic beer regardless, and had really smooth and rich caramel and light roast flavors with excellent body and head retention.

As soon as it didn't meet my expectation, I instantly started formulating the adjustments it would need to become more like that Old Rasputin. So, in this high gravity stout, I made those corrections, while adding a couple subtleties that allow it the title "Scottish Imperial Stout."

I raised the level of roast by doubling the Brown malt and increasing the Roasted Barley. This will definitely add to the overall roast character. I kept the hops very similar, but added a whole ounce at knock-out. Throughout the whole fermentation, a wonderful hop nose popped out of the airlock.

The only things I'm worried about this time around is the gravity/ABV. I used a different yeast for this stout...Wyeast Scottish Ale. With a target of 1.094, the OG came in a bit low, at about 1.088. Not too bad, but the FG might end a bit high as well. It's a good thing for Scottish ales to finish higher, and the same yeast fermented two prior beers beautifully (1.040-1.018 & 1.058-1.028). So, we'll see if this Imperial brew finishes low enough to give it an ABV around 8+%.

Fermentation was almost instantaneous, and tons of foam created yet another brewing mess this year (see the others here). The blow off collection tub tipped and overflowed, spilling over two good books and a couple rugs. As the 65°F fermentation started to slow, I switched on an airlock and moved it indoors where the temp rose to about 70°F. I've been spinning and disturbing the yeast cake at least twice a day since slowing down.

This beer will have a subtle essence of Scotch and Oak. Some light oak chips went into the primary after settling a bit. Then in secondary aging, it will get at least 1 ounce of Scotch (The Belvenie: 12 year, double wood) soaked, medium-dark French oak cubes. Every week I'll sample it to see if it needs more time, or more oak/Scotch. But I'm going for a super light subtlety here.

Scottish Imperial Stout

Grains
14.0 lbs. Organic 2-Row
1.00 lbs. UK Brown Malt
1.25 lbs. UK Faucett Crystal 95-115L
1.00 lbs. UK Amber Malt
0.65 lbs. UK Chocolate
0.45 lbs. UK Roasted Barley


Hops
2.25 oz. Centennial, 9.1%, pellet, 75min
1.25 oz. Centennial, 9.1%, pellet, 5min
1.00 oz. Northern Brewer, 7%, pellet, 3min
1.25 oz. Centennial, 9.1%, pellet, KO


Yeast
Wyeast 1728: Scottish Ale yeast cakes

Brew Day Stats

Brewed: 3/6/09
Racked: 3/27/09
Bottled: 5/11/09

Water Adjustment:
Strike: 1 tsp Gypsum, .25 tsp Acid Blend, 1 tsp Chalk
2nd Sparge: 1 tsp CaCl, .25 tsp Kosher Salt

H2O/Grain Ratio: 1qt/lb
Mash Ph: n/a
Sacch. Rest Temp/Time: 152-149°F/70min
Mash Out Temp/Time: 167°F/Vorlauff
1st Batch Vol/SG: 4.6gal/1.068

2nd Batch Sparge H2OTemp/MashTemp: 180°F/171°F
2nd Batch Vol/SG: 3gal/1.038
2nd Batch Extra Vol: .5gal collected & added to boil

Pre-Boil Vol: 8 gallons
Pre-Boil SG: 1.060
Boil Time: approx 3 hours
Post-Boil Vol: 5.25 gallons
Mash Efficiency: 70%

OG: 1.088
IBU: 77
Color/SRM: Black/47
Ferment Temp: 66-70°F

FG: 1.027
ABW: 6.4%
ABV: 8%

4 comments:

travis said...

That's a thick mash, is that a stout thing or just preference?

Ted Danyluk said...

Travis, it is a thick mash. It's not a stout thing.

I like around 1.5 qt/lb but my system gets very inefficient as the gravity goes up.

I think fly sparging is better for stronger than average brew, while batch sparging is great for the lighter styles. But in this case it was a batch sparge.

Replacing some of the mash out water into the strike volume, would help get a thinner mash, but the mash out temp would be lowered towards 160°F or less.

And the 2nd sparge water was already on the low side, and much is needed to rinse the grains effectively. It was draining still fairly dark, and a 3rd batch could have rinsed even more.

Even with the shy water volume, this brew still required a full 3 hour boil. So next time...I'll fly sparge (gee haven't done that in a very long time) and perhaps record a difference.

Rich Thometz said...

Ted, I dropped you an email the other day. I met you in the brew store. Did you receive the email? My email is thometz@sbcglobal.net

Ted Danyluk said...

Got it Rich. I will get in touch with you soon.