It’s obvious, really. There are thousands of pumpkin beers out there; it’s been done. Who’s ready to brew with a different holiday staple that is every bit as American and, as a bonus, has a sweeter, more intense flavor? I yam.
“A lot of people do pumpkin beer,” says Bror Welander, senior shift brewer at Odd Side Ales in Grand Haven, Michigan. “We actually don’t do any pumpkin beers. But we thought it would be cool to do something for Thanksgiving and release it on Black Friday. And what do people like to enjoy on Thanksgiving?”
Behold, Odd Side’s Sweet Potato Soufflé. It’s a big, dark, dessert-like strong ale that usually gets some barrel-aging. The version that won gold for Specialty Beer at the 2017 Great American Beer Festival spent time in rye whiskey barrels.
“It’s barrel-aged and a bigger beer,” Welander says. “It’s got a little more cachet in late fall, early winter.”
But there are all sorts of barrel-aged strong ales out there. Precious few are made with yams. In this case, the brewers add fully cooked mashed sweet potato to the whirlpool—almost 40 pounds of it go into a 10-barrel batch of beer.
“In the past, we have used sweet potatoes that we cooked ourselves, but that was many years back,” Welander says. “Now we use our local food service. The sweet potatoes come mashed already. There are no additives or anything. It is straight-up mashed sweet potatoes.”
At whirlpool, he says, “we take the same pot, and obviously with rubber gloves on and everything, we just add it handful after handful. One handful at a time, so it really gets blended in well.” In other words, don’t just dump it all in at once. “It dissolves nicely into the whirlpool.”
Odd Side has a 15-barrel brewhouse, but this is a beer with a lot of stuff in it, including the yams. “We can’t fit in all the grain we’d want and hit our final gravity,” Welander says. The beer also gets some lactose and malt extract to kick up the body, sweetness, and strength. The grain bill is big, though, and gives a lot of body—enough that the beer remains weighty despite a relatively low mash temperature. “You would think that a big ale like this would be mashed at 156°F (69°C) or something. But no, this one’s mashed at 149°F (65°C).”
The beer also gets modest dashes of cinnamon, nutmeg, and allspice, which are added after fermentation is complete. They mix the spices in a bit of 195°F (91°C) water from the hot liquor tank to sanitize them, then add them to the fermentor or barrel. As with pumpkin beers, the spices help to evoke that sweet-potato-pie/casserole/soufflé flavor.
The barrel aging has been a hit but is not strictly necessary. “You certainly could get a really nice final product without the whiskey barrel,” Welander says. Odd Side has been making Sweet Potato Soufflé since 2012, but the recipe has changed over time—though its current incarnation is more or less unchanged since it won a gold medal.
The changes have mainly been with the barrels, including two different versions aged in Traverse City Whiskey casks. For one, the barrels had previously held honey; for the other, maple syrup.
“We like to tweak and skew it toward our endgame.”