GF Oatmeal Milk Stout Advice

Hi All,

I want to make a GF oatmeal milk stout for a friend as an Xmas gift, but I'm a complete novice when it comes to GF brewing. I've come up with the following recipe and would like your expert opinions. I've been perusing the GF thread all day and have gotten some great info, so here's what I've come up with (numbers are per BeerSmith):

Dave's Oatmeal Milk Stout

Batch Size: 3 gallons
Type: Partial Mash; Single Infusion, Fly Sparge
OG: 1.060
FG: 1.012
ABV: 6.3%
IBUs: 37
SRM: 28
Boil: 60 minutes

Ingredients

Mash
1.5 Lbs Oats, Flaked, Roasted
0.5 Lbs Corn, Flaked
0.5 Lbs Rice, Flaked
1/2 tsp Amylase enzyme
2 tsp pH 5.2 Stabilizer
--- Mash in with 4.13qts water @ 160.8F (152F Step Temp) for 60 min
--- Mash out with 3.38qts water @ 189.7F (168F Step Temp) for 10 min
--- Fly Sparge with 2.82 gal water @ 168F

Boil
0.33 oz Magnum hops @ 60 min
1/2 tsp Irish Moss @ 30 min
1.5 Lbs Briess White Sorghum Syrup @ 30 min
1 Lb Treacle, Dark @ 30 min
0.5 Lb Candi Sugar, Dark @ 30 min
0.5 oz Sovereign hops @ 10 min
4.0 oz Maltodextrin @ 10 min
4.0 oz Lactose @ 10 min

Fermentation
Primary: 7 days @ 70F
Secondary: 14 days @ 70F; Cold crash @ 34F last 2 days
750 ml Burton Ale Yeast (WLP023), Sorghum Starter w/ stir plate & nutrients
0.5 oz Sovereign hops, dry hop 14 days in secondary

Bottling
1 tsp Black Walnut Exract
2.5 oz Dextrose for priming
Age 30 days @ 70F

Make sure you roast the oats really dark. I'd leave out the corn and rice and just do all oats. Use more like 2 tsp of amylase enzyme, and use LOTS of rice hulls. Adding some gypsum provides calcium, which also helps stabilize the enzymes.

In the boil, I'd halve the treacle, cut the candi sugar, and add at least a pound of D-180 candi syrup. I use that in my oatmeal stout and it's a friggin' god-send. I also would use more sorghum extract; if you're expecting to get 75% efficiency on your mash with just amylase, think again. I'd calculate based on around 50% efficiency, and make up the difference with sorghum and candi syrup. Or better yet, cut out half the sorghum and replace with rice syrup or rice solids.

Also, black walnut extract? I've never used it, but if this is an x-mas present, I'd err on the side of "less experimental" and leave it out. Unless you're really familiar with the stuff and have used it in stouts before.

Thanks Igliashon for the quick reply! I made the changes you suggested in BeerSmith with a 50% total efficiency and 50% mash efficiency as well as your ingredient suggestions and I agree it looks like a much better recipe. I used black walnut extract in a brown ale I did and it's fantastic (provides a very smooth, unusual flavor), though I've since cut it down in this recipe to 1/2 tsp because I want it just as an accompaniment. It's strong, though, so it's better to use it sparingly. Here's the final recipe unless you or anyone else has additional ideas.

Dave's Oatmeal Milk Stout

Batch Size: 3 gallons
Type: Partial Mash; Single Infusion, Fly Sparge
OG: 1.055
FG: 1.010
ABV: 5.9%
IBUs: 36
SRM: 27
Boil: 60 minutes

Ingredients

Mash
3.0 Lbs Oats, Flaked, Roasted (30 SRM)
1.5 Lbs Rice Hulls
1.5 Lbs Rice, Flaked
0.5 tsp Gypsum
2 tsp Amylase enzyme
2 tsp pH 5.2 Stabilizer
--- Mash in with 8.5 qts water @ 162.3F (152F Step Temp) for 60 min
--- Mash out with 5.3qts water @ 197F (168F Step Temp) for 10 min
--- Fly Sparge with 1.7 gal water @ 168F

Boil
0.33 oz Magnum hops @ 60 min
1/2 tsp Irish Moss @ 30 min
1.0 Lb Briess White Sorghum Syrup @ 30 min
0.5 Lb Treacle, Black @ 30 min
0.5 Lb Candi Syrup, Dark (D-180) @ 30 min
0.5 oz Sovereign hops @ 10 min
4.0 oz Maltodextrin @ 10 min
4.0 oz Lactose @ 10 min

Fermentation
Primary: 7 days @ 70F
Secondary: 14 days @ 70F; Cold crash @ 34F last 2 days
750 ml Burton Ale Yeast (WLP023), Sorghum Starter w/ stir plate & nutrients
0.5 oz Sovereign hops, dry hop 14 days in secondary

Bottling
1/2 tsp Black Walnut Exract
2.5 oz Dextrose for priming
Age 30 days @ 70F

One other thing: I'd be wary of adding those sovereign hops at 10 minutes. Sweet stouts don't generally benefit from hop aroma, and it seems like it would be a waste of a great aroma hop. You should be fine on this one with just a bittering addition, or at least that's what popular wisdom dictates.

Gotcha. Took them out and added more magnum. My biggest fear was having the sorghum taste bleed through, which I haven't experienced for myself but have read can be unpleasant. I think with this recipe the sorghum will add what it needs to add without tasting like a GF beer. I tasted one of my friend's commercial varieties (a pale or amber ale, if I remember correctly) and it had a strange aftertaste. Thank you again for all the advice and I'm sure my friend will love it.