Oatmeal stout is a popular variant of Stout introduced in the late 19th century and famous for its smooth, creamy, silky texture. This week we’ll talk a bit about the history of oatmeal stouts, the beer style, how to design a recipe for one and how to brew it.
As mentioned in my earlier article on Dry Irish Stout, as well as my podcast on Irish Stout with John Palmer, all modern stouts trace their heritage back to Porter, which was an immensely popular drink in the 17th century. As far back as 1677, the term “stout” was used to describe “strong” beers, and most beers in that time period were dark ales (what we would call Porters) because malt at the time was kilned over fires – true Pale malt did not arrive until the early industrial revolution brought coal fired malting.
The term “Stout ” was used to describe strong beers of various kinds well into the 1800’s, and evolved over the century to refer to strong very dark “Stout Porters”, or simply “Stouts”. Oatmeal Stout was first widely marketed in the late 1800’s as a nutritional drink. The marketing worked well as oats were though to have a restorative, nourishing and healthy effect in Victorian England.
The use of oats in beer was not a modern innovation, however, as oats were widely used for ales in medieval Europe. The use of oats in beer had largely died out by the 16th century, with the exception of Norway where it was still used.
Oatmeal stout sales flourished in the late 19th and early 20th century, and continued to be brewed until shortly after World War II. However, in the 1950’s most breweries stopped producing oatmeal stout, and by the early 1970’s no commercial examples remained. However, brewer Samuel Smith revived the style in the late 1970’s and since then hundreds of small and micro-breweries have produced Oatmeal Stouts.
The Oatmeal Stout Style
Many beer fans are surprised to find that oatmeal stout has very little oatmeal flavor. Instead the oatmeal adds a rich, creamy, silky character to the beer due to the high protein, lipid and gum content. Several early commercial examples included very little oatmeal (less than 1%), though most were made with between 5% and 30% oatmeal by weight. Using more than 30% oatmeal will lead to an astringent flavor and bitterness.
The BJCP style guide describes Oatmeal Stout as a variant of sweet stout that is less sweet, and relies on oatmeal for body and complexity rather than lactose. It may have a roasted grain aroma mixed with a light sweetness, with little fruitiness or diacetyl. Hop aroma and flavor are low, and it may have a slight oatmeal aroma.
Color is medium brown to black (22-40 SRM), with an original gravity of 1.048-1.065 which results in an alcohol content of 4.2-5.9%. Bitterness is in the 25-40 IBU range, with a bitterness ratio in the 0.5 IBU/GU range.
Brewing an Oatmeal Stout
The grain bill for an oatmeal stout typically starts with UK or American pale malt, which generally comprises about 60-80% of the grain bill. Oats are the next major component, making up 5%-25% of the bill in most recipes, though some extreme examples use as much as 30% oats. I personally recommend targeting the 10% oats to start with.
A variety of grains are often added to enhance body and complexity including Caramel/Crystal malts, Cara-Pils, Cara-Foram malt, flaked barley, and occasionally even wheat or flaked wheat. These typically are included in the 5-10% (each) weight range. When using Caramel/Crystal malts, the darker versions are often favored to add color and caramel sweetness to the beer.
The stout character and color is usually achieved by using Chocolate malt and Black Patent malt (along with the Caramel mentioned earlier). These are typically constrained to 4-10% (each) of the grain bill to achieve a stout character without creating an overwhelming roasted coffee flavor, as oatmeal stout should be in the “sweet stout” family, and not dry like Irish stout. Stout roast and roasted barley is generally not used in oatmeal stout as it adds too much “coffee” or “burnt” flavor to the mix.
Traditional English or American bittering hops are used such as East Kent Goldings, Fuggles, Centennial, Willamette, Northdown, etc… to balance the strong dark malts. As hop aroma and flavor is not a significant characteristic of oatmeal stout, it is rare to add finishing or dry hops. Instead, enough boil hops should be used to properly balance the beer (about 0.5 IBU/GU).
Some all-grain brewers prefer to use a full bodied mash profile (around 156 F for conversion) to further enhance the body of the beer, while others have advocated lower temperatures (148 F) to achieve a cleaner fermentation of barley malt and enhance the oatmeal character. I tend to prefer a medium to full body mash profile to preserve the sweet character of the beer as the finish should be sweet and not overly dry.
English ale yeasts are traditionally used with oatmeal stouts. I try to select a strain without excessive ester (fruit) or diacytl (butterscotch) production that will still leave residual sweetness in the beer such as White Labs WLP002. You don’t want a yeast that ferments too cleanly, as complexity is part of the flavor, but you also don’t want an English yeast that is too fruity.
Fermentation is done at normal ale temperatures and the beer may be bottled or kegged. Traditional stouts are served with fairly low carbonation and warm, but many American drinkers prefer a moderate carbonation and chilled beer.
Oatmeal Stout Recipes
Here are a few oatmeal stout recipes from the BeerSmith Recipe Archive:
- Dirty Pig Oatmeal Stout – Extract
- Muddy Pig Oatmeal Stout – Extract
- Oatmeal Cookie Monster Stout – Partial Mash
- Oatmeal Stout – All Grain
- Oatmeal Stout by Gregar – All Grain
- Prairie Oatmeal Stout - All Grain
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