The smoked malt was chosen based both off of my last smoked beer and what I had on hand (Applewood smoked malt that I'd received way back at the Baltimore NHC). I also used 3 types of oats (flaked, golden naked, and malt) because I had all of them on hand. The choice to use pilsner malt was also due to having a sack of it, I would probably opt for Maris Otter or a different characterful pale malt were I to do it over.
As I did with my Of Greater Things smoked helles I was able to add the smoked malt to the second "mash" of the Parti-Gyle.
The decision to use Imperial Organic Yeast's A04 Darkness and White Labs 095 Burlington Ale were last minute decisions when at the LHBS due to lack of Wyeast 1469 West Yorkshire Ale yeast and their descriptions seeming close to what I was looking for in each.
Both batches took off extremely fast and had blown out their airlocks and were overflowing carboys with krausen within 12 hours. I switched to blowoff tubes and let them keep going for two weeks, at which point each one was exactly at their estimated FG. Primed to have 2.0 volumes carbonation the beers seemed pleasant and promising at bottling.
Imperial Oatmeal Stout:
Appearance - Pours jet black and seemingly opaque with a half finger tan head that quickly fades to a ring. The head retention might be negatively impacted by proteins and oils in the oats and the high alcohol, along with the low carbonation level.
Smell - Dark fruits (cherry, dried cranberry, cabernet sauvinon) and toffee swell as soon as the bottle is opened with notes of toffee, toast, and dark chocolate in the mix and becoming more present as it warms. No distinct hop aromas, but there is a light touch of woodiness and a hint of ethanol booziness.
Taste - Less complex than the aroma with the roast malt dark chocolate character leading with some nice toast and biscuit malt character filling out the rest. Light toffee and fruit characters blend with moderate biterness (seemingly from both malt and hops) and a warming booziness that leaves a lingering dark chocolate covered raisin meets rum finish.
Mouthfeel - Low carbonation, not bad for style but maybe a touch lower than expected/intended. The mouthfeel is somewhat lighter than the 1.022 finishing gravity would imply with the lingering heat and dryness keeping it from feeling as full bodied as it may otherwise feel.
Overall - This beer got positive reviews at a recent DC Homebrewers meeting with one member asking for the recipe and others praising the balance and complexity, especially as it warmed. While the booziness is a touch higher than I'd like and the carbonation a touch lower I think the beer is a solid offering.
Session Smoked Oatmeal Stout:
Smell - Again fruits are big but this time they lean more orachard (apricot/peach and a touch of orange). The smoke melds in as a prominent but not overwhelming (to my senses) component. Baked muffins and a touch of yeasty/fresh dough character also show through. The roast malt seems to be lost. No hop character. No booze apparent.
Taste - Mild smoke blends with light orchard fruit and a finish of semisweet chocolate. There is flavor to the beer but nothing very strong, mild toast, mild currant, mild apricot, mild chimney fire. Finish is equally balanced between low sweetness and a touch of bitterness. Chocolate and toffee come through more as it warms and the beer seems best at fairly warm temps.
Mouthfeel - This beer is more in need of higher carbonation than the imperial version due to the lower body and lack of power in the flavors. The beer comes off as fairly watery and lacking, with just a touch of the creaminess expected from an oatmeal stout. The very long mash and low for the style 1.011 finishing gravity keep it from really feeling like an oatmeal stout, or a stout at all.
Overall - Perhaps session smoked porter would be more accurate due to the lack of body, but even then this beer would be lacking. There's nothing too offensive about this beer, but there just isn't much of anything to this beer. It's fairly easy to drink, and the smoke is nicely integrated, but this beer would need more oats and more roast to be entertaining at this strength.
While I'm not in love with either of these beers I'm not unhappy with either as they are both free of off flavors, are balanced and drinkable, and have enough difference to make the split batch worthwhile. I probably would not do this again with these styles but could see doing something similar with either an increased malt addition for the second beer or taking the smaller beer in a completely different direction (Schwarzbier, Black IPA, or Black Saison?). For my next oatmeal stout I intend to use a more characterful base malt, a slight increase in roasted malts, and maybe even a little more caramel or toasted malts.