It's no secret that I love dark beers (mmm, Belgian stout!), especially during the dark days of winter.  When the weather turns cold nothing else comes close to a hearty dark beer in a warm pub with friends.  One of my personal favorite styles is a porter.  Porters come in several styles, ranging from sweet to dry, with roasty, malty and chocolatey flavors being common across the range. 

One of my favorite styles of porter is the robust porter, BJCP style 12B.  I put together this recipe for a competition, and like it enough that it has become a staple in my brewing rotation.  Like any good English style of ale, it starts with a generous helping of Maris Otter pale malt.  A few lbs of speciality grains layer on the roast flavors in abundance.  Finally, I like to toss in a little sour (acidified) malt.  It isn't needed to lower the mash pH, as the roasted malts will do a fine job of that.  I just like the slightly lactic character that it adds to the finished beer.  Here's the total grain bill:

9.5lb Maris Otter pale malt

2lb biscuit malt

1lb chocolate malt

1lb black malt

0.5lb sour (acidified) malt

I dough this in at 1.25qt/lb with a target mash temp of ~150F.  60 or 70 minutes is more than enough time to complete conversion.  Sparge with your choice of method until you get about 6.5 gallons of wort.  Sticking with the English theme, the hops in this recipe are all traditional English fare:

1oz East Kent Goldings (5% AA) - 80 mins

1oz East Kent Goldings (5% AA) - 20 mins

1.25oz East Kent Goldings (5% AA) - 5 mins

The boil time is a little longer than the usual 60 minutes for a homebrew recipe.  I think this helps darken the beer a bit more (not that it needs it!) and helps develop the flavor a bit more.  Once the sweet wort is cooled down, pitch an appropriately English yeast strain.  I've brewed this with Wyeast 1275 Thames Valley and White Labs WLP004 Irish Ale, and both turned out great.  Just find something fairly neutral with good attenuation.  On my brewing rig the starting gravity usually comes out between 1.065 and 1.070.  After fermentation it gets down to around 1.015, yielding an ABV of 6.5%- 7%.  Keeping with the traditional theme, carbonate to about 2 volumes of CO2.  I've done this beer force carbonated in the keg and bottle conditioned and it turns out fine either way.  The beer will come out inky black, and should raise a firm mocha colored head.  For a fun variation, use this as the base recipe for some porter exploration.  I've brewed this with black licorice added, with some smoked malt and even with a couple handfuls of ground coffee.  Just the thing for a break from the snowball fights and sledding!

Happy brewing!