Advice on recipe for extra oatmeal milk stout

[josephort]

With everything going on in 2020 and now what feels like an unusually cold fall here in the Midwest, I really want to brew a big, dark, sweet, smooth, luscious beer to help keep me sane as winter approaches. I found this recipe for a high-ish gravity oatmeal milk stout from The Growler, originally credited to Michael Dawson's book. I think I'd like to do this this weekend, so I've slightly tweaked it to make a 6-gallon batch and to account for the fact that I generally get poor efficiency on high-gravity beers:

15 lbs Mariss Otter
1.75 lbs Flaked Oats
1.5 lbs Blackprinz
1.5 lbs Pale Chocolate
1 lb Crystal 120
1 lb Lactose
1 oz Bravo (or any ~15 AA bittering hop) @ 60 mins

Mash with 6.75 gallons @ 155 F, Batch sparge with 4 gallons.
Pitch US-05 from slurry off my last batch, ferment around 66 F.
OG 1.083/FG 1.023/8% ABV/42 IBU/SRM 50

I'd appreciate any feedback on this- I've never brewed with lactose before, and generally my stouts and porters tend to be much more on the dry/roasty end of the spectrum. I feel like this recipe has a lot of sweetness in it between the lactose and the C120 and the high mash temp, but it also uses a higher proportion of dark malts than I would typically consider. My hope is that these two factors will balance out and create a really decedent but balanced flavor profile, but I can also imagine missing the mark and making something too cloying, too roasty, or just too intense all around.

Would love any and all insight, especially from folks who have ever brewed a beer along these lines or have more general experience with beers in the sweet stout family.

Cheers!

 

[tennesseean_87]

I've also never brewed a sweet stout, but am working on a recipe in a more moderate gravity range.

One thing I will note from my experience is that using dehusked and paler roast malts allows you to use more of them. I usually follow the standard 70/20/10% basemalt/flaked/roast in my dry stouts, but recently did one up with 13% since I split between pale chocolate (200), chocoalte, and roast barley. My recipe is using that same proportion I like in my dry stout, but I might even up the amount by a smidge to give plenty of roast character over the lactose backbone. I've also used dehusked in stouts with cold steeping overnight in much higher percentages than would usually work, and it was great. I wouldn't worry about being too roasty.

 

[josephort]

Just brewed this yesterday, wound up getting significantly higher efficiency than expected so now it's a full-blown Imperial (OG 1.107). I'm a little nervous about the possibility of a stuck fermentation with so much unfermentable sugar in such a high gravity wort, but I pitched a large healthy slurry plus an extra packet of dry yeast I had on hand, pitched on the cool side, and aerated for a couple minutes with a stick blender (no pure O2 on hand, unfortunately), and I've got bubbles in the airlock, so fingers crossed! Will report back as it goes for posterity.

 

[couchsending]

Something is wrong.., you don’t go from 1.083 to 1.107 due to an increase in efficiency alone.

 

[josephort]

1.083 was predicted for a 6 gallon batch based on 60% efficiency. 1.107 was measured for the actual 5.75 gallons I collected, which implies 75% efficiency. I don't think this suggests a problem, other than that I am bad at predicting what my efficiency will be when I brew a new recipe.

 

[tennesseean_87]

15% is still a huge efficiency swing, and you can always add a quart of distilled water to get things back to where they need to be.

 

[josephort]

In case anyone stumbles across this thread while planning their own recipe in the future, I just want to report back that this beer fermented nicely, is now done, and is delicious. Sweet-but-not-too-sweet, velvety smooth, rich, flavorful, and definitely strong. When planning the recipe I worried that it it would wind up being too cloying between the lactose, high mash temp, and crystal malts, but that didn't wind up being a problem at all, so future brewers brewing similar beers should feel free to pump up the sweetness with confidence.

 

[marc1]

In case anyone stumbles across this thread while planning their own recipe in the future, I just want to report back that this beer fermented nicely, is now done, and is delicious. Sweet-but-not-too-sweet, velvety smooth, rich, flavorful, and definitely strong. When planning the recipe I worried that it it would wind up being too cloying between the lactose, high mash temp, and crystal malts, but that didn't wind up being a problem at all, so future brewers brewing similar beers should feel free to pump up the sweetness with confidence.

What did your FG end up at?

 

[josephort]

What did your FG end up at?

1.030, which means 10% ABV. That implies 78% attenuation (accounting for the lactose) which is slightly lower than I expect from US-05, but I think can be accounted for by the high mash temp.