This week I take on another beer recipe design case study of the classic Irish Stout style.
The Irish Stout Style
The classic Irish Stout is obviously Guinness, first brewed by Arther Guinness at St James’ Gate in Dublin Ireland. I’ve had the privilege of visiting the brewery a few years back and a fresh Guinness in the tasting room in Dublin is an outstanding beer experience. Guinness is dominant in Ireland and arguably the most recognizable stout in the world.
While traveling in Ireland I was trying to sample some of the local beers. At two different pubs I attempted to order another brand of beer, only to be told by the server that “You don’t want that – you want a Guinness.” They both poured me a Guinness! Apparently the other beer taps are just for show.
The local draft version of Guinness is a fairly low alcohol beer in the 3.5-4% range. The BJCP style guide lists the original gravity in the 1.036-1.044 range, and ABV as 3.9-5%. Bitterness is a moderate 25-45 IBUs and color in the black 25-40 SRM range.
The dry acrid flavor comes from the use of stout roast/roasted barley. Roast barley is an interesting “malt” as its actually not malted at all but instead just raw barley roasted at very high temperature. The rich thick body in Irish Stout comes from a generous dose of flaked barley.
Design Decisions
Though my Irish Stout recipe dates back some 20 years, it is arguably one of the easier all grain beers to brew. The roast barley is so strong it hides most flaws in your brewing process, so its actually a hard beer to mess up. If you want to learn more designing recipes, this article on the principles of beer recipe design is a great place to start, and you will see many of its elements reflected here.
For a base malt, I use UK Pale malt, though arguably just about any pale malt will do. The other malts are dominant, so there is not a big reason to use a flavorful base malt like Maris Otter on this beer. While my rule of thumb for beers is to use no more than 20% specialty malts, for this particular style I break that rule and actually have about 30% specialty malts and 70% base malt. The reason for this is that I will use a big flaked barley addition to drive the body way up without significantly altering the flavor.
The next major addition is the flaked barley. For this recipe I use 20% flaked barley, which is basically unmalted barley that has been flaked like corn flakes so it can be mashed and converted. Flaked barley leaves a fair amount of proteins and unfermentable starches in the finished beer, which provides the thick mouthfeel we closely associate with Irish Stout. It also makes the beer punch above its low alcohol level, so it feels like a bigger beer than it is.
In sticking with the principle of simplicity, the remaining 10% of the malt bill is the defining flavor malt, which is roast barley, sometimes called stout roast. As I mentioned above this is also unmalted barley that has been roasted at high temperature. It has the magic dry, acrid, bitter finish we associate with Irish Stout, but lacks the sweetness, melanoidins and warmth you might get from Black Patent or Chocolate Malt. Roasted barley is the defining malt, so you don’t need to add anything else to it.
For water, many years ago brewers made a big deal out of brewing stouts with water high in bicarbonates. Dublin water is fairly soft with a moderate level or calcium, low sulfates and chlorides and a slightly elevated level of about 200 ppm bicarbonates. However the bicarbonate level is well within the roughly 0-250 ppm range that is considered normal for brewing water, so it is slightly elevated. I’ve brewed my recipe with no water salt additions using a moderate base water and it comes out fine, so I don’t think you need to really do much adjustment with your brewing water if it is within the normal range.
Given the huge amount of roast barley in this recipe, it is unlikely you will need to make any mash pH adjustments, but you can use a bit of lactic acid if the pH is too high. For mash temperature, I mash either with a medium body mash profile. You could go with a higher temperature full body mash if you like, but the 20% flaked barley usually adds plenty of body to the beer with either option.
Hopping is actually an important topic. While many brewers are familiar with the concept of the bitterness ratio and balancing your hop level with the original gravity, it is also important to balance hopping levels with the color of the beer for darker beers. A very dark beer with a lot of roast malt requires an elevated level of bitterness to balance out the roast malts. If you hopped this beer based purely on its low original gravity it would actually be out of balance. I used 44 IBUs of East Kent Goldings in a single boil addition in this beer which is at the high end of the range for the style (30-45 IBUs), but the hops are needed to offset the 10% black barley. East Kent Goldings is one of my favorite British hops as it has a nice complexity to it.
So overall, the brewing process is very straightforward for this beer. A base malt and two specialty malts, a simple single infusion mash, and just one boil addition for hops.
For yeast, I choose the Wyeast 1084 Irish Ale yeast, though you could use the White Labs WLP004 or any number of other vendor’s Irish Ale yeasts. I’ve also heard that other brewers have made this recipe with other English Ale yeast variants with great success. The beer does not require any special fermentation other than to keep it around room temperature. It also does not require extended aging, and you can typically enjoy it within two weeks.
Traditional Irish Ales are served at a fairly low carbonation level, though here in the US we often elevate that a bit. If you want full authenticity you can use a CO2/Nitrogen mix when kegging your Irish Stout, as this is how the draught Guinness is served. It does require a kegging system, bottle of mixed CO2/nitrogen and an elevated serving pressure. Of course the nitrogen works best with a true Stout Tap.
I have literally brewed this beer dozens of times, and it always comes out great! Here are the recipe link for the final recipe:
I hope you enjoyed this weeks in depth look at one of my favorite beers – the dry Irish Stout. Thank you for joining me on the BeerSmith Home Brewing Blog. Be sure to sign up for my newsletter or my podcast (also on itunes…and youtube) for more great tips on homebrewing.
