Scottish Oatmeal Stout: used Scottish Export style guidelines to start, but adding more Roasted Barley (to darken and get roast flavor) and Flaked Oats, and selected Oatmeal Stout guidelines afterward (since it hits all the numbers). Use a Scottish Ale strain to be more authentic, but I wanted a dry yeast, so going with S-04 fermented on the cooler side. Or just switch the GP to MO and call it a regular Oatmeal Stout... guess it's somewhere in between.
Using "kettle caramelization" technique to increase maltiness/maillard flavors - take 2 quarts of wort after mash into smaller pot, and boil until reduced by 75%... so end up with 1 pint (1/2 quart) syrup-like wort. Add that back into main wort boil before flame out. (If you don’t want to do this, add more crystal malt to grist… maybe 10% total.)
Start with 4.1 gallons mash. Lose about .375 gal to grain absorption = 3.725 total preboil volume. Take 0.5 gal of that and boil separately to reduce to 0.125 gal. 3.725-0.5 = 3.225 gal preboil in main boil... 0.6 gal/hr boil off will reduce that to 2.625 post-boil in main boil. Then adding back the 0.125 gal caramelized reduction gets us to 2.75 gallons total into the fermentor. Lose about 0.25 gal to trub, so end up with 2.5 gallons into keg or bottles.