NOTE: In the 2015 BJCP Style Guidelines, Oatmeal Stout is now Style 16B in Category 16 Dark British Beer which contains average to strong, bitter to sweet, modern British and Irish stouts that originated in England even if some are now more widely associated with Ireland. In this case, “British” means the broader British Isles not Great Britain.
The information below is still valid for the style, but use it in conjunction with the current style description if studying for the current BJCP exam.
Oatmeal stouts are very popular with homebrewers, and for good reason. If you love stouts, and who doesn’t, or are new to the style, an oatmeal stout is a good introduction to the style. It is sweeter than a dry stout but not as sweet as a Sweet Stout. It is super creamy with a luxurious long lasting head. The flavors are of dark roasted-grains with a bitter chocolate and coffee and cream notes. It’s like the English version of a dark milkshake.
It was a very popular beer in the 1800’s when it was thought to be a nutritious supplement to people’s diet. In actuality, most oatmeal stouts only contain about 5% oatmeal in the entire recipe due to problems with astringency when more is added. Even so, the marketers jumped at the chance to claim their beers were healthy, and the beers were even prescribed by physicians for lactating mothers and sick children.
The style was popular in the late 1800’s but declined soon after as the last oatmeal stout was brewed before World War I. Samuel Smith Old Brewery revived the style in 1980, just in time for the craft beer movement in the U.S. Homebrewers adopted the style along with all beers English and it has remained popular ever since.
Oats give the stout a rich creamy (most often described as “silky”) mouthfeel and a huge long-lasting head. Oats can add a nutty, grainy, or earthy flavor, but too much can make the beer seem astringent (although the other big flavors in a stout can sometimes hide this character). One other problem with using a little too much oats in the grist is that the mouthfeel can go from “silky” to “oily”. It seems that around 10% of the grist is the threshold for this oiliness and an intense flavor.
Some things to consider when brewing an oatmeal stout are: when most people, judges included, think of an oatmeal stout, they imagine a beer that is very rich in body and mouthfeel with a big nutty or biscuity flavor from the oats. To get this impression in the beer, you can roast your flaked oats in the oven at around 300 degrees F (149 degrees C) until they begin to turn brown and you can smell the oatmeal cookie notes. To make sure you get enough of the nutty-biscuity character, a small amount of Victory malt helps as well. To get the correct amount of mouthfeel and body, use flaked oats and mash at around 154 degrees F (68 degrees C). Use a yeast that does not fully attenuate the beer, such as the popular Wyeast 1968 London ESB or White Labs WLP002 English Ale to allow some residual impression of sweetness. Keeping the hop bittering in check will also help with the impression of sweetness in this beer.
Oatmeal Stout Description
- Aroma: The aroma should be of mild roasted grain, often with a coffee-like character. You should also note a light sweetness that can leave you with a coffee-and-cream impression. The fruitiness should be low to medium. Diacetyl in this beer should be medium-low to none. The hop aroma should be low to none (UK varieties most common). A light oatmeal aroma is optional but highly desired.
- Appearance: An Oatmeal Stout should be medium brown to black in color with a thick, creamy, persistent tan to brown-colored head. It can be opaque (if not, it should be clear).
- Flavor: The main impression should be of a medium- sweet to medium-dry palate, with the complexity of oats and dark roasted grains present. Oats can add a nutty, grainy or earthy flavor to the beer. Dark grains can combine with malt sweetness to give the impression of milk chocolate or coffee with cream. There should be a medium hop bitterness with the balance toward malt. Diacetyl should be medium-low to none and hop flavor medium-low to none.
- Mouthfeel: It should have a medium-full to full body, smooth, silky, sometimes an almost oily slickness (if the percentage of oats is high) from the oatmeal. It should definitely be creamy with medium to medium-high carbonation.
- Overall Impression: Overall, an Oatmeal Stout will be a very dark, full-bodied, roasty, malty ale with a complementary oatmeal flavor.
- Comments: Sweetness generally falls somewhere between sweet and dry stouts, although some beers fall in the extremes of being fairly sweet to quite dry. The level of bitterness also varies, as does the oatmeal impression. Light use of oatmeal may give a certain silkiness of body and richness of flavor, while heavy use of oatmeal can be fairly intense in flavor with an almost oily mouthfeel. When judging, allow for differences in interpretation.
- History: An English seasonal variant of sweet stout that is usually less sweet than the original, and relies on oatmeal for body and complexity rather than lactose for body and sweetness.
- Ingredients: Pale, caramel and dark roasted malts and grains. Oatmeal (5-10%+) used to enhance fullness of body and complexity of flavor. Hops primarily for bittering. Ale yeast. Water source should have some carbonate hardness.
- Vital Statistics: OG: 1.048 – 1.065 FG: 1.010 – 1.018 IBUs: 25 – 40 SRM: 22 – 40 ABV: 4.2 – 5.9%.
- Commercial Examples: Samuel Smith Oatmeal Stout, Young’s Oatmeal Stout, McAuslan Oatmeal Stout, Maclay’s Oat Malt Stout, Broughton Kinmount Willie Oatmeal Stout, Anderson Valley Barney Flats Oatmeal Stout, Tröegs Oatmeal Stout, New Holland The Poet, Goose Island Oatmeal Stout, Wolaver’s Oatmeal Stout.