If you know someone whose surname is 'Porter' and you like to brew, then I imagine that it's fairly inevitable that you will end up brewing something dark for them at some stage. My friend Jessica recently gave up her beery name when she got married to my long-time drinking partner Adam, but before he could strip her of her birthright, I brewed them a chocolately imperial porter.
Back in March, when I wasn't sure what to brew for my 4th all-grain brew, I canvassed on Twitter and someone suggested brewing a baltic porter (I'd credit you but I can't search that far back - it may well have been
David Bishop). Given that I'm not in a position to do a cold ferment with the equipment I have, I couldn't do a true BP, but I liked the idea of doing a stronger-the-average porter with a traditional ale yeast. Knowing that Jess isn't a huge fan of really robust, roasty flavours (which is kind of important in a porter), and after the relative success of flavouring my first brew by using coffee beans in the secondary, I started looking on homebrew forums for shared recipes for flavoured porters. For some reason, cherries are really popular with American homebrewers (I guess it must be sort of Black Foresty but I can't say it appeals that much to me), along with chillies, ginger and even cinnamon sticks. One of the most popular recipes of all was for a 'Bourbon Vanilla Imperial Porter', originally devised by Oregon homebrewer Denny Conn - and I used this as the basis for this brew. There's a cracking Q&A with Denny that mentions the formulation of this recipe
here.
Denny's recipe - or at least the iteration I saw, as it's been passed around, Chinese-whisper style, quite a bit I think - is pretty decadent. It's heavy on the sweeter malts (approx 7.5% Crystal, 7.5% Brown Malt, just under 6.5% Chocolate Malt...) and specifies adding two whole vanilla beans when racking to secondary. As per the name, he also includes some bourbon at bottling, while some recipes I've seen add oak along with the vanilla beans, but I wanted to keep the number of variables down so omitted them from my version. I also tweaked the proportions of the malts ever so slightly as the original recipe was given in imperial and I didn't want to end up with lots of open bags of the malts I was buying specially for this recipe.
Malt bill:
6kg Maris Otter
1.25kg Munich
750g Brown Malt
500g 'Dark' Crystal Malt
500g Chocolate Malt
300g 'Regular' Crystal Malt
Mash profile was a simple single infusion (to keep it simple) at 68°C, with tap water treated with a couple of Campden tablets - with the amount of grain in the tun and with the way we mashed in by pouring water onto the grain, I found it very hard to avoid balls of dry dough, even after stirring relentlessly. I need to work on my efficiency! Sparged with more of the same to collect just over 23l of wort at 1.066 - a satisfyingly straightforward mash-and-sparge compared to a couple of the gummy nightmares I've had.
As per Denny's original recipe, I used Magnum to bitter (28g, first wort) and then 28g of East Kent Goldings when the IC and Irish Moss went in with 15 mins to go. (At this point I didn't have a hose connector sorted for the IC, so myself and my brother took it in turns to freeze our hands by trying to clamp the end of the hose over the cold tap for the hour it took to get down to pitching temperature - I don't recommend the experience.) As you can see, gravity at pitching was 1.074 - 5 points short of target, but better than I'd feared given the dry, doughy mess the tun had been.
Wyeast 1056 was pitched (with a 1.5l starter), and it was kept more-or-less at 22°C, using the ultra-high-tech towel-and-clothes-pegs temperature control method, for 10 days, by which time it was down to 1.022 - again, a few points short of the target, but the yeast had had enough, leaving it at 6.8% ABV (on the weaker side of imperial - perhaps dynasterial?). My theory on the lower attenuation is that there were some colder spots in the mash tun around the doughy clumps, hence a less fermentable wort - any suggestions welcome.
Two big, fat Madagascan vanilla beans were halved and scraped into the secondary at racking, then the shells quartered and thrown in as well. In hindsight we should probably have sterilised them in vodka but no harm done. Another 10 days on and there was a good, strong vanilla aroma and flavour, which really helps to bring out the chocolate and smooths off the roastiness.
The big problem came when bottling - I hadn't really worked out how to prime correctly at this point, and rather than making a solution and mixing it in, I added approximately 4-5g of sugar to each 330ml bottle. Clearly this is far, far too much for a porter - perhaps as much as three times as much as needed - and the result is that while the first bottles that I tried after only a week had the right volume of gas in them, as time has gone on the carbonation has gotten a bit out of hand. I haven't had any bottle bombs yet, thankfully, but I have had to pour them out and let them settle.
Six months on from the brew day, at Adam and Jess's wedding, I cracked some open for our friends to try, and - once the fizz had subsided - I'm really happy with it. The vanilla has settled back to a background note (but hasn't disappeared altogether), and the main body of the body is rich and caramelly. More importantly, the woman herself seemed to like it, which was the whole point in the first place, so I'm happy. I'm planning to brew this again at some point... although clearly I'll need a new name now that she's married.
