Imperial Stout Recipe

Hey guys, had a couple of questions regarding this stout recipe....Imperial Bastard Stout.

This will only be my second attempt at brewing (the first was a canned Cooper's IPA, hey, it was free when I bought my equipment)

I really would like to try it out, but would like to do a full boil instead of the partial 2 gal. How would I adjust the recipe? Or am I being too ambitious by trying to brew this?

Thanks in Advance

I don't think you'll really have to adjust the recipe at all. There are a few things to consider.

You MAY need less hops, because you'll have better isomerization of your hop oils in the lower gravity boil. IMO though, I like my stouts pretty bitter, so I probably wouldn't adjust this. I don't have the tools or the time to make the IBU calculations here at work, but it's something to consider.

Also, unless you have 40 quart kettle or something, you're probably going to have to do at least a little bit of a partial boil. You're probably going to lose 1 - 2 gallons during the boil, so, unless you start off with 6 - 7 gallons of boiling water, you're going to have to top off your wort a little bit with fresh water.

I would call this an "advanced style" with its high OG. It is sometime difficult to get yeast to ferment hight OG brews out completely. High OG worts can stress yeast cells. Going with a big starter and aeration would be my suggestion.

If you are planning on doing a full boil, then you will want to adjust the hop additions to account for better utilization. Take the target IBUs and your hop AA% and use brewing software to adjust accordingly.

Another option would be to make the wort without adding the extra dark DME and brown sugar and instead add after the the first round of fermentation is finishing up. This way, you aren't stressing the yeast by adding them to a wort with a high OG. Just a thought.

broadbill said:

Another option would be to make the wort without adding the extra dark DME and brown sugar and instead add after the the first round of fermentation is finishing up. This way, you aren't stressing the yeast by adding them to a wort with a high OG. Just a thought.

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That's interesting, I'm not familiar with that technique. I've heard of adding half of your fermentables at the end of the boil, but never after primary. Do you lose anything from not boiling the extract and sugars?

DRoyLenz said:

That's interesting, I'm not familiar with that technique. I've heard of adding half of your fermentables at the end of the boil, but never after primary.

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Its different. As an extract brewer, you might add the majority of your fermentables at the end of the boil to prevent carmelization and color changes.

By adding fermentables after fermentation started, you avoid stressing the yeast by pitching them into a wort that has a high OG. What you are effectively doing is "feeding" them throughout fermentation.

DRoyLenz said:

Do you lose anything from not boiling the extract and sugars?

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Maybe. Boiling extract/sugars promotes carmelization/Maillard reaction that might be a desirable flavor in a style like a stout. You might have that covered already by using roasted barley.

What you will be doing is boiling a lower OG so you might have to adjust your IBU again to account for this.

broadbill said:

High OG worts can stress yeast cells. Going with a big starter and aeration would be my suggestion.

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The recipe calls for an Irish Ale yeast, what is the best way to prepare a big starter for something this high in OG?

broadbill said:

If you are planning on doing a full boil, then you will want to adjust the hop additions to account for better utilization. Take the target IBUs and your hop AA% and use brewing software to adjust accordingly.

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I am looking into a brewing software right now, any suggestions other than Beersmith? Also, since I do not currently have software, are there manual calculations I can make? Thanks again for the guidance

I used JP's How To Brew as a reference last time I did these calculations by hand. Since his online version is different than the hardcopy I own, I can't guarantee you this has exactly what you need.

http://www.howtobrew.com/section1/chapter5-5.html

I'm going try and run these calculations myself, just to keep myself sharp, but this is definitely worth the read.

KingPin461 said:

I am looking into a brewing software right now, any suggestions other than Beersmith? Also, since I do not currently have software, are there manual calculations I can make? Thanks again for the guidance

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I used JP's How To Brew as a reference last time I did these calculations by hand. Since his online version is different than the hardcopy I own, I can't guarantee you this has exactly what you need.

http://www.howtobrew.com/section1/chapter5-5.html

I'm going try and run these calculations myself, just to keep myself sharp, but this is definitely worth the read.

sorry about the double post....

Thanks for the link, I'll read into it. I'm headed down to the LHBS to pickup the items I need for this batch.

I don't have a 40qt kettle, but I do have a 30qt, might be cutting it close for a full boil I guess.

I do have one more question regarding carbonation levels (v/v of CO2) for a stout like this. Would I have to run it on mixed gas (75% N and 25% CO2) like Guinness? Or will straight CO2 be ok?

BTW I plan on kegging

KingPin461 said:

I am looking into a brewing software right now, any suggestions other than Beersmith? Also, since I do not currently have software, are there manual calculations I can make? Thanks again for the guidance

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Ok, I've been working on these manual calculations for about an hour and a half (it's been a slow day at work, and this is my first time doing these calculations manually). I was able to get almost all of the information I needed from that John Palmer page, and various references on the internet (like finding the Yield of the various fermentables). The only thing I couldn't find was the IBUs at such a high gravity when only doing a 2 gallon boil. I learned a lot, so I would suggest you go through the practice of doing these calculations.

I decided to download BeerSmith on my work computer, and was able to get you the calculations in a second, it really is a phenomenal tool. However, it appears that that Bitterness specs on the link are either incorrect, or I'm doing something wrong. I posted an inquery about it on the thread for that recipe, so I'll get back as soon as I figure out what's up.