Milk Vs Oatmeal Stout: What's The Difference?

If you're a beer drinker, you've likely encountered dark, hearty stouts like Guinness. When you come across a beer with an almost black color and a malty flavor (often featuring caramel or chocolate notes), you know you've got a stout. But in the world of brewing, you can add extra ingredients to your stout to change the flavor, leading to popular beers known in craft brewing circles as oatmeal stouts or milk stouts.

The names are fairly straightforward, and so is the explanation for what sets them apart: An oatmeal stout is a typical dark beer with oats added into the mixture, which gives it a more robust nutty flavor and oatmeal taste alongside a smooth consistency that connoisseurs often refer to as velvety. Similarly, a milk stout has lactose added — a natural sugar that appears in milk — which makes it creamier and sweeter. So, beyond the ingredients and taste, an oatmeal stout would be vegan, while a milk stout is not.

Key differences between these stouts

While one of the most popular stouts in general would be Guinness, popular milk stouts might include Left Hand Brewing's Milk Stout Nitro and Stone Brewing's Mexican hot chocolate-inspired Xocovesa, and popular oatmeal stouts would be drinks like Founders' Breakfast Stout and Samuel Smith Old Brewery's Oatmeal Stout. But there's a wide variety of both kinds out there. Because of their sweet, almost dessert-like qualities, milk stouts might be a better choice for those who usually don't drink craft beers much. If you're already an adventurous beer drinker, you may lean toward oatmeal stouts.

To illustrate this better, it helps to understand what exactly a stout is. A stout is a very dark-colored type of ale. Ales and lagers are two main varieties of beer — ales are brewed at warmer temperatures with yeast that ferments at the top, while lagers are brewed at cooler temperatures with yeast that sinks to the bottom. Stouts are brewed with roasted barley, and oats or lactose may be added to make different types of stouts.

Oats, milk, and oysters

Stouts are a comprehensive family encompassing many different beers, and oatmeal or milk stouts are just two different kinds. Guinness is a dry Irish stout, which is much less sweet than the kinds of stouts we've been getting into — although because of its rich chocolatey taste, it's not among the most bitter beers, either. It has a very low alcohol content at only 4.3%, unlike its more potent cousin, the Russian Imperial stout, which is unique among stouts for its alcohol content of 8% or higher.

Alongside oatmeal and milk, you also have pastry stouts – rich, sugary, and high-alcohol beers that taste more like a dessert. You also have coffee stouts, which are traditional stouts brewed with coffee. Most uniquely, you have oyster stouts, which are, in fact, made with oysters. Despite the seafood, there isn't a strong fishy taste in oyster stouts, just a subtly briny flavor reminiscent of sea salt.