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Author Topic: Scaling up a stout to an imperial stout  (Read 9078 times)

Offline ccfoo242

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Scaling up a stout to an imperial stout
« on: May 31, 2012, 10:24:58 pm »
While I'm not a huge fan of imperial stouts I'd like to give one a try. I thought it might be fun to scale up the oatmeal stout recipe from Brewing Classic Styles and take a few liberties with it. What I'm not sure about is scaling specialty grains. If I double the grain bill do I really want to double all of the dark grains? I think with this I will take Gordon Strong's advice and cold steep the dark grains in an attempt to reduce harshness from them.

Here's what I've got so far:
BeerSmith 2 Recipe Printout - http://www.beersmith.com
Recipe: Argument From Authority
Brewer: Steve
Asst Brewer:
Style: Imperial Stout
TYPE: All Grain
Taste: (30.0)

Recipe Specifications
--------------------------
Boil Size: 8.00 gal
Post Boil Volume: 6.50 gal
Batch Size (fermenter): 5.50 gal   
Bottling Volume: 5.10 gal
Estimated OG: 1.106 SG (1.091 if 60% efficient)
Estimated FG: 1.029 SG  1.025 SG  (1.022 if 60% efficent)
Estimated Color: 54.9 SRM
Estimated IBU: 74.3 IBUs
Brewhouse Efficiency: 70.00 %
Est Mash Efficiency: 79.5 %
Boil Time: 90 Minutes

Ingredients:
------------
Amt                   Name                                     Type          #        %/IBU         
16 lbs                Pale Malt, Maris Otter (3.0 SRM)         Grain         1        69.6 %       
2 lbs                 Oats, Flaked, Toasted (1.0 SRM)          Grain         2        8.7 %         
1 lbs 8.0 oz          Victory Malt (or biscuit) (Briess) (28.0 Grain         4        6.5 %         
1 lbs                 Caramel/Crystal Malt - 80L (80.0 SRM)    Grain         6        4.3 %         

Cold Steep and add at 10 minutes:
1 lbs 8.0 oz          Chocolate Malt (350.0 SRM)               Grain         3        6.5 %         
1 lbs                 Black Barley (Stout) (500.0 SRM)         Grain         5        4.3 %         

28.00 g               Northern Brewer [8.50 %] - First Wort 90 Hop           7        22.3 IBUs     
42.00 g               Magnum [12.10 %] - Boil 60.0 min         Hop           8        40.5 IBUs     
11.00 Items           Fermcap-S (Boil 60.0 mins)               Other         9        -             
28.00 g               Northern Brewer [8.50 %] - Boil 20.0 min Hop           10       11.5 IBUs     
1.00 tsp              Irish Moss (Boil 15.0 mins)              Fining        11       -             
5.50 tsp              Yeast Nutrient (Boil 15.0 mins)          Other         12       -             
2.0 pkg               Dry English Ale Yeast (White Labs #WLP007)     Yeast         13       -             
  *** use 2 vials in a 1.5L starter with stir plate, per Mr Malty calculator
2.00 oz               Oak Chips Soaked in Irish Whiskey (Secon Flavor        15       -             


Mash Schedule: My Mash/Sparge
Total Grain Weight: 23 lbs
----------------------------
Name              Description                             Step Temperat Step Time     
Mash In           Add 7.37 gal of water at 167.7 F        154.0 F       90 min       

Sparge: Batch sparge with 2 steps (Drain mash tun, , 3.49gal) of 168.0 F water
Notes:
------


Created with BeerSmith 2 - http://www.beersmith.com
-------------------------------------------------------------------------------------
« Last Edit: June 01, 2012, 06:27:39 pm by ccfoo242 »
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Offline chezteth

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Re: Scaling up a stout to an imperial stout
« Reply #1 on: May 31, 2012, 10:52:38 pm »
I think the recipe sounds good.  In my experience with a beer that big my efficiency usually drops.  I usually calculate 60% efficiency with a beer that big.  Also, I'm assuming you will be making a starter.  Even 2 vials of yeast will not be enough for this beer.  Other than that I say "go for it"!

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Brandon

Offline snowtiger87

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Re: Scaling up a stout to an imperial stout
« Reply #2 on: June 01, 2012, 03:05:15 am »
With a beer this big you would be much better off brewing a regular gravity beer (1.050 or so) and harvesting the yeast for this batch.

The grain bill looks fine to me.
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Offline ccfoo242

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Re: Scaling up a stout to an imperial stout
« Reply #3 on: June 01, 2012, 05:01:25 am »
The 2 vials were for a starter according to Mr Malty.

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Offline ccfoo242

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Re: Scaling up a stout to an imperial stout
« Reply #4 on: June 01, 2012, 06:11:41 am »
Followup question: with an FG of 1.029 is this going to be like syrup? The biggest problem I have with imperial stouts I've tried is they are too sweet for my taste. Should I use a more attenuative yeast like WLP007 (Dry English Ale)?
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Offline Rhoobarb

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Re: Scaling up a stout to an imperial stout
« Reply #5 on: June 01, 2012, 08:04:48 am »
I prefer WLP007 in big beers like this, as well as my Irish Stout and Irish Red.  I like the recipe, btw.
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Offline Joe Sr.

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Re: Scaling up a stout to an imperial stout
« Reply #6 on: June 01, 2012, 08:31:42 am »
Followup question: with an FG of 1.029 is this going to be like syrup? The biggest problem I have with imperial stouts I've tried is they are too sweet for my taste. Should I use a more attenuative yeast like WLP007 (Dry English Ale)?

I think 1.029 will taste sweet, but maybe not like syrup.

I have a quad fermenting right now with a similar OG to your recipe that stalled at about 1.025 and it was very sweet.  Too sweet, for me.  But I like my beers strong and dry.

My old ale also starts around the same OG and tends to finish around 1.015.  Definitely not overly sweet at that FG.

The alcohol should offset some of the sweetness, but I'd go for something a bit more attenuative.
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Offline kylekohlmorgen

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Re: Scaling up a stout to an imperial stout
« Reply #7 on: June 01, 2012, 09:02:23 am »
If you want a drier version of a RIS, you can go lower but I wouldn't shoot for below 1.025 or so. It needs that residual sweetness or it feels thin and bland (my biggest problem when brewing RIS is actually over-attenuation).

1 lb of black barley is a LOT. Investigate dehusked to reduce astringency, especially since you're shooting to dry it out a bit more than usual. Replacing 75% of the dark roasted grains will reduce astringency but give you just enough bite to balance out the sweetness (along w/ the hops and alcohol). The hop bitterness will fade, the astringency wont.
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Offline ccfoo242

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Re: Scaling up a stout to an imperial stout
« Reply #8 on: June 01, 2012, 06:22:21 pm »
Thanks everyone for the input.  I've edited my original post and changed the yeast to WLP007.

If you want a drier version of a RIS, you can go lower but I wouldn't shoot for below 1.025 or so. It needs that residual sweetness or it feels thin and bland (my biggest problem when brewing RIS is actually over-attenuation).

1 lb of black barley is a LOT. Investigate dehusked to reduce astringency, especially since you're shooting to dry it out a bit more than usual. Replacing 75% of the dark roasted grains will reduce astringency but give you just enough bite to balance out the sweetness (along w/ the hops and alcohol). The hop bitterness will fade, the astringency wont.

Looks like WLP007 will bring it down to 1.025 (assuming my efficiency doesn't drop, I looked at 60% and it's still quite a big beer with no additional grain or adjuncts).

As for the astringency I'm going to cold steep the dark grains and add them late in the boil. This should, according to Gordon Strong, reduce the astringency.

Also, I'm not going to soak the oak in whiskey. I will add the oak then, per Denny's article last month, I'll get the right amount of whiskey to add prior to bottling by adding some to samples then scaling up.

I re-listened to the Jamil show on imperial stouts and the one on oak aging today and I think I'm on the right track. The only thing I won't be doing that was suggested is repitching from a previous beer. I'll just have to create a decent starter and aerate the heck out of it.
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Offline hoser

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Re: Scaling up a stout to an imperial stout
« Reply #9 on: June 01, 2012, 06:55:08 pm »
I wouldn't be surprised if WLP007 takes you below 1.025.  I routinely get 78-80% attenuation with this yeast, no matter the size of the beer.

Offline dannyjed

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Re: Scaling up a stout to an imperial stout
« Reply #10 on: June 01, 2012, 07:21:14 pm »
You could also add some sugar or candy syrup to get your FG down a bit.
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Offline rjharper

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Re: Scaling up a stout to an imperial stout
« Reply #11 on: June 04, 2012, 12:31:08 pm »
I would mash cooler personally.  Anytime I'm making a BIG beer like this, and I'm pushing the limits of attenuation, I go for 149 F, and let the yeast go as far as they will. There will still be plenty of body left with 75%+ attenuation from 1.100.

Offline ccfoo242

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Re: Scaling up a stout to an imperial stout
« Reply #12 on: June 04, 2012, 12:50:03 pm »
I'm at work right now but when I get home I'll work in these suggestions. 

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Offline ccfoo242

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Re: Scaling up a stout to an imperial stout
« Reply #13 on: June 04, 2012, 08:51:18 pm »
So, according to Beersmith if I lower the mash temp to 150F then my FG should be 1.020 (1.017 @ 60% efficiency).

I think I'll try that and if I miss my pre-boil gravity then I'll add sugar to bring it up.
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Offline hoser

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Re: Scaling up a stout to an imperial stout
« Reply #14 on: June 04, 2012, 08:59:12 pm »
I would add DME as opposed to sugar if I miss my efficiency/OG, but that is just me. But, in a beer that big it may not matter.