Imperial Stouts and Fermentation

[Isaacf]

this is kind of a 2 part question. I am creating an imperial stout recipe and am hoping someone can tell me if I am crazy or if it looks good. I am also not sure how long to ferment or whether or not I can let it age in my secondary. Can it be at room temperature for a year or do I need to bottle condition sooner? How much yeast do I need?

5 gallon
Pale 2 row 17lbs
Flaked Oats 2.13lbs
Black Barley 1.06lbs
Roasted Barley 1.06lbs
Caramel/Crystal 80 .5lbs

Hop additions
Cascade 3oz
My hood 1oz
Magnum .5oz

London Ale 1028

 

[mattdee1]

My first impression looking at your recipe is that it might turn out a bit harsh tasting with all those burnt grains and so little crystal. Personally, I'd prefer a combo of C60 and C80 (or maybe some Caramunich) to make up 7-8% collectively, add in 5% of chocolate malt, and reduce the burnt grains down to 1-2% or leave them out entirely.

If you're really unsure, it's probably best to find a recipe on this site that has dozens and dozens of people vouching for it... that way you don't have to fuss over recipe details and can just focus on getting the process right.

For yeast, some people are going to try to tell you that you need to use a yeast calculator to get it right but honestly, beer is pretty forgiving as long as you get in the right ballpark. For that beer I'd just pitch 2 packages of S-04 dry yeast and call it a day. If you're using liquid yeast, build up a starter of 2-2.5 L and that should do the trick. If you're just planning to dump the contents of the liquid yeast pack into the wort without making a starter, I'd get at least 2 packages.

I've never aged a beer long term in a secondary, but I'm not sure why you'd want to do that. Just ferment the beer in primary 2-3 weeks and then bottle it. Store the bottles somewhere cool and dark and let them age that way.


Good luck

 

[cactusgarrett]

That's a LOT of roasted grains for a 5 gallon batch. In addition to amount, you only need one type of roasted barley; I'd drop the Black Barley and replace it with Chocolate malt. Reel that in a bit. I would search the database here for a tried & true RIS recipe and go from that. Typical RIS don't have oats, either.

Assuming a 7gal boil and 5.5gal into the fermenter, you're looking at 1.106 (give or take, depending on the calculator). Using a yeast pitch rate calculator, you would need 6 liquid packs to have enough yeast for this OG (522 billion cells target). Obviously a starter (likely a multi-step one) is more prudent. Personally, if a calculator tells me I need, say, 6 packs, i'm content with the equivalent of 4, as I've never had issues with slight underpitching. Like matt stated above, beer is pretty forgiving. HOWEVER, at an OG of ~1.106 you are setting yourself up for bad things if you don't pitch close to enough yeast. I'm talking bad off flavors and more likely a stalled fermentation. I would pitch no less than 3 packs, or do a multi-step or huge starter, and pitch it into your batch during very active fermentation.

Hops - you don't give a schedule, so i'm assuming those are all 60 min bittering additions. If so, you're looking at 85 IBU. Reasonable for this OG.

Fermentation - this could take a while due to the OG. I would give it no less than 3 weeks, even if you hit your target FG somewhat quickly. After that, it would likely need 6 months to age and come into it's own after flavors mellow and meld together. Some would argue that leaving it on the yeast cake for that long is okay. I don't think I'd personally go beyond 6 months without transferring it to a secondary for aging, but that's more a function of me needing to free up my primary fermenter. Room temp or below is good for long-term aging. Conversely, taking it off the cake to bottle and age that way in 2-3 weeks would be doing the beer a disservice, as I believe great benefits are had by allowing the yeast to clean up after itself for a long while after primary fermentation is done.

 

[CascadesBrewer]

I am fairly new to Imperial Stouts. I brewed my first batch (2.5 gal) in January, and it just keeps getting better. I will claim that I keep opening bottles as a learning experience to understand how a big beer ages, not because I am impatient. That was (1.104 OG):

• 9 lb 2 Row Pale Malt
• 8 oz Crystal Malt 80
• 6 oz Roasted Barley 300L
• 6 oz Black Malt 500L
• 1 oz Northern Brewer 60 min
• 0.5 oz Simcoe 10 min
• 16 oz slurry of S-04

I just brewed a second batch with minor tweaks. This time I ramped up to a 4 gal batch. A 4 gal batch was as big as my 10 gal pot would handle for full volume mash. Plus I could dust off my "secondary" 5 gal carboy. That batch was (1.108 OG):

• 16 lb 2 Row Pale Ale Malt (Viking this time, vs Briess)
• 1 lb Flaked Barley
• 1 lb Crystal Malt 80
• 10 oz Roasted Barley 500L (note 500L vs 300L)
• 10 oz Black Malt 500L
• 1 oz Summit 60 min
• 0.8 oz Simcoe 10 min
• 1 packs S-04

I pitched 2 packs of S-04 on Sunday, noticed solid signs of fermentation on Monday, left for 4 days of vacation, and came home to 1" of liquid in the bottom of my fermentation chamber (set at 66F...the yeast was happy and I guess my blow off container was too small). Gravity had dropped to 1.041 so I moved it to sit in my lower level bathroom to finish.

My overall plan is to leave it in the primary fermenter for about a month, then decide if I want to keg and bottle from the keg, or if I want to bottle condition. I am not sure I am a huge fan of the idea of leaving a beer in a fermenter for a year. It just seems like too many opportunities for things to go wrong, vs bottle conditioning.

 

[Isaacf]

Thanks for all the replies! Here is what I am going with:

2-row 17lbs
Crystal 80 1lb
Roasted barley .25lbs
Chocolate .25lbs
Oats 1lb for mouthfeel

Cascade 4 oz at 90 minutes
London ale yeast

I don’t much care for chocolate or coffee. I want a smooth bitter beer with a hint of caramel. I may age it with some oak chips.

 

[yowzers]

You can also add a few ounces of Black Patent malt to add deep color without any burnt flavor. I love it in my Porters and Stouts. To answer your second question, I would definitely skip the secondary altogether and bottle after 3 weeks in Primary. Age in bottles for sure.

 

[cactusgarrett]

Also consider cold steeping your roasted grains overnight and adding it to the mash runoff/boil. Another option is capping the mash by adding the roasted grains during the vorlauf/sparge. Both work to knock down the harsh roast flavor that comes from straight mashing them, and smooths the beer out a bit.

This, of course, is if you want that. I would imagine knocking that characteristic down a bit would not be to style.