Beyond ‘Roasty’: The Surprising Psychology of Stout

We are visual creatures—but color is deceptive. Randy Mosher, author of Tasting Beer, shares insights to help us widen our stout vocabulary.

Randy Mosher Feb 5, 2021 - 10 min read

Beyond ‘Roasty’: The Surprising Psychology of Stout Primary Image

Photo: Matt Graves

Rich, dark, deeply flavored, and sometimes beastly, stouts are a style that people don’t like—they love. Or hate. There’s no “meh” in stout-land. The near-universal rap from the haters is that they’re “heavy,” or strong, or filling, and occasionally they are. But one of the world’s most popular stouts isn’t even as strong, or rich, or filling as your average mass-market lager—it’s as light on its feet as a ballerina—and you can dance with her all night long.

Whether we’re a drinker or a brewer, our misperceptions revolve around our psychology—especially the way our brains integrate our senses and bring them to our consciousness. As tasters, we like to think we’re pulling apart the various threads of taste, aroma, mouthfeel, and that elusive synthetic construct called flavor. But that’s not how we’re built. Shaped by billions of years of evolution, our chemical senses are gloriously effective at translating the outside world into an action plan. The results of this unconscious sensory integration are notions that are strongly motivating, either attractive or repulsive. Analysis takes too much time in the heat of the moment; we’re not all that good at it anyway.

Our every sensory experience is shaped not just by the sensations of the moment but by a lifetime of expectations and experiences that set the framework for what is delivered to our window of consciousness. We rarely have access to the raw data. We struggle to focus on the parts when our mind really wants to give us the bottom line.

Colors, Names, and Other Lies

In the case of stouts, the sensory elephant in the glass is color. We’re supremely visual creatures. If we see something meaningful, our brains will try to find a way to support it even if it’s not actually there. This has been studied over and over in many contexts, and it’s inescapable. The wine people have just given up, often judging red wines in black glasses to avoid polluting their evaluations with erroneous visual cues.


There is relatively little we can learn from the appearance of a beer. As Michael Lewis, the legendary brewing-science professor of UC Davis, is fond of saying, “Color is not a flavor outcome.” This is doubly true for stouts. Dark color is highly correlated by our experience with roasted and even burnt things and, of course, chocolate and coffee.

Color taints our understanding of the whole spectrum of malt color. In our everyday lives, as something is roasted darker and darker, it becomes more intensely flavored. And while that’s true to a point, it does not match the reality of how malt is roasted. Up to a coppery-brown color—about 100° Lovibond or 200 EBC—flavor intensity really does increase, as the heat creates volatiles. But at that point, they turn ugly, with harsh, wet ashtray smells. The malts in this 100–200°L (200–400 EBC) range are so nasty, they’re just not available. With continued roasting, those volatiles start to blow off into the smokestack. Maltsters sometimes use techniques to enhance this process, such as spraying the roasting malt with water mist, which instantly evaporates, creating a vacuum near the kernels that helps suck the offending chemicals out of the grains.

Above 200°L (400 EBC), the malt is usable again, but as roasting continues up to about 600°L (1200 EBC), the chemical reality is just the opposite of that our eyes are seeing. The malt becomes less intense in flavor as it gets darker.

Chocolate malts are the most coffee-like, but the word “chocolate” brings up another psychological issue: Language can “prime” our sensory system, setting up expectations the same way our eyes do. This underpins the power of marketing and so many other uses of language. We are almost powerless to resist it, especially since we’re barely aware of how affected we can be. That’s why structured tasting of ingredients can be so helpful.


Finding More Flavors

At one of my breweries, we recently did a tasting of about 20 different malt “teas,” made by briefly soaking dark malts in hot water, then straining, filtering, and adding to a pale lager to taste it in a beer context. The variety was amazing. Even within the same color range, every maltster’s flavors were different, often strikingly so. Vocabulary ran the gamut from nutty to milk- and dark-chocolate to fig, raisin, and caramelized prunes to latte, coffee, and espresso. Some malts were less inviting—more like stale diner coffee or burnt and acrid.

Dark-chocolate or lighter black malts can straddle the coffee-or-chocolate fence. Black malts can range from espresso to dark chocolate. Roasted malts from lager-centric places (Weyermann’s Carafa series, for example, from Bavaria) often have a smooth, chocolaty character. This is especially so for those made from dehusked malt, which removes phenolic material that can add harshness. Roasted, unmalted barley is traditional in Irish stouts and is responsible for a sharp coffee-like aspect that helps to define the style.

On the negative side, astringency can be a problem in stouts. In the best of circumstances, it can add balance with a kind of soft, tannic quality. Harsh astringency is a problem, so it’s always something to put on your tasting checklist; look for it in that long, dark finish.

Outside of careful malt selection, there are techniques to minimize harshness. Instead of mashing in with them, add the dark malts before lautering—this still extracts plenty of color and flavor, but it reduces the time for harsh tannins to leach into the brew. Another is a cold-brew method: Soak all the dark and caramel malts overnight, then drain and add to the kettle with the runoff. This is an impressively effective technique, resulting in very smooth-tasting brews.


When looking for other flaws, be aware that roasty intensity can sometimes camouflage them. Diacetyl, for example, brings a very out-of-place buttery aroma and flavor to pale beer. Yet it feels at home in a dark beer—so if I find myself thinking that this tastes just like brownies or cake, I know that’s a sign to sniff again and search for that telltale butteriness.

Toward Greater Depth

Another issue with the appearance of stouts is to assume that the roasty malts must dominate the taste of the beer as completely as they do its color. Roasted malt and grains do bring a lot to the stout party, but there’s much more to a good stout. Look past the darkness and focus on the layers of flavor underneath, which should be there if the brewer has thoughtfully formulated the recipe.

Mid-colored malts can easily stand up to roastiness, adding luscious caramel, nutty, toffee, toasted marshmallow, cake, and cookie flavors to a stout. Crystal malts can add caramel, raisin, dried fruit, and other aromas that add depth and personality. You can think of a well-brewed stout like a box of bonbons: They’re chocolate on the outside, but that gets a little boring after the first couple; sometimes you want to grab one with a center of caramel, or nougat, or nuts.

Some stouts, particularly strong ones, do have these confectionary flavors added to the roast, caramel, toffee, and other flavors that the grist provides. Nuts, chocolate, and coffee are all popular with drinkers but challenging for brewers because they’re expensive, and their oily nature make them only partially soluble and prone to affecting head retention. Fruits—especially berries—are sometimes added, but they can be tricky. Roasty flavors can overwhelm them pretty quickly, and their acidity can add to the sharpness—which is already fairly high, even with a great recipe and masterful brewing.

Vanilla, whether added as an ingredient or obtained via oak-aging, can shift the balance much more to chocolate, since vanilla is ubiquitous in chocolate-flavored candies and desserts. It also adds a perception of sweetness based on our expectations. The popular “pastry” stouts rely heavily on this, often supplementing it with the unfermentable sugar, lactose. These beers are notable for their intensity of flavors and sweetness; these help to stimulate transporting memories of childhood encounters with convenience-store treats, but they also take a toll on drinkability.

I like stouts and all kinds of dark beers, and I wish more people embraced them for their depth and roasty charms. We’re so close already; they embody so many different flavors that people profess to love and consume in great quantities—just look at the drive-through line at Starbucks. They ought to appreciate stouts just as fully. I can’t help feeling that maybe they’re just thinking about them wrong.