is a sub-style of stout, the distinction being the inclusion of up to 20% oats by weight in the grist. The addition of oats, a cereal grain with high concentrations—relative to barley—of body-enhancing beta-glucans, water-soluble lipids, and proteins, adds a distinctly silky and rich mouth feel to the beer.

Stouts brewed with oatmeal became popular in late 19th-century England, with the stout style in general, and oatmeal stouts in particular, being associated with nourishment and viewed as healthful, restorative drinks. By the middle of the 20th century, however, the style had largely disappeared. A mention of oatmeal stout in Michael Jackson’s 1977 tome The World Guide to Beer led an American beer importer to commission such a beer from Samuel Smith, a brewery in Yorkshire, England. Since the creation of that first modern oatmeal stout, the style has grown in popularity with more than 100 commercially brewed examples available today.

Workers unloading fresh hops into traditional oast houses for drying in Kent, England, c. 1900. pike microbrewery museum, seattle, wa

Oats are most often used as rolled oats, added directly to the mash, usually at around 10%–15% of total grist weight. Alcohol content by volume varies from as little as 4% to as high as 7.5%, with most examples below 6%. Oatmeal stouts are often somewhat sweeter than dry stouts, but less sweet than sweet stouts or milk stouts. Hop bitterness varies with each brewer’s interpretation of the style but is generally moderate, with an emphasis on bittering, rather than aroma hops.

See also stouts.