Brewing with Pumpkins: Tips from the Pros

In the past, when pumpkin beers took over craft beer shelves each fall, it was an array of various approaches to the same beer style. More recently, brewers have been more creative in their approach to brewing with pumpkin. Here’s advice from three brewers, who make everything from classic to imperial stout pumpkin ales.

Cambridge Brewing Co. (CBC) was the first brewery east of the Mississippi to produce a pumpkin beer since colonial times with our Great Pumpkin Ale. Over the past 10 years we have brewed dozens of other single-batch beers with pumpkin, from stouts to schwarzbiers to IPA to barrel-fermented wild ales. Depending on how it’s used, pumpkin can offer a nice soft flavor and a bit of additional body to a beer. It’s a subtle character, to be sure. Some different heirloom varieties of pumpkin and other hard squashes can offer more flavor than the typical pie pumpkins. My favorites are Blue Hubbard squash, Grey Ghost, and Jarrahdales.

At CBC, we exclusively use whole, fresh, Massachusetts-grown pumpkins. All the pumpkins are washed and scrubbed, chopped open, scooped of seeds and guts, and then sent through a food processor and turned into shreds. The pumpkin shreds are added in the brewhouse the very next day. We never use cooked pumpkin, purees, or “natural flavorings.” We add the pumpkin directly into the mash tun along with our grist, in a single-infusion mash typically targeting a high-ish conversion temperature of 154 °F (68 °C). Our rule of thumb as a starting point is to use about a 1⁄2 pound per gallon (0.06 kg per L) of pumpkin. We’ll double it in a strongly flavored base beer, if we need to.

The Great Pumpkin Ale uses only cinnamon and allspice, nothing else. We keep it very simple, and very subtle. Think 1⁄2 gram per gallon (4 L) of each spice. We’re not big fans of a spiced beer that you can smell long before it hits the bar — it’s always about balance. By using fresh pumpkin we achieve a nice, fresh squash flavor in our beers, and by a restrained use of spices we are able to honor the base beer style, add a soft hint of fresh squash. In the case of a pumpkin IPA, the squash is typically overwhelmed by hop character. Heavy roast can obscure it as well. So the important question to ask is really “how much actual pumpkin flavor am I looking for, versus spice flavor or base beer character?” If you want noticeable pumpkin flavor in a robust porter, you should plan on doubling the pumpkin to at least a pound per gallon (0.12 kg per L).

In what we now call “traditional pumpkin ale,” meaning an amber-colored beer with caramel malt profile, pumpkin, and spices, I feel a fruity English strain like London Ale or West Yorkshire are outstanding. Otherwise, if you’re making a pumpkin wheat use a good Bavarian weizen strain. For a pumpkin Pils use something like the 34/70 Weihenstephan, etc. Our focus is always on creating a solid base beer, which just happens to have this strange squash cultivar as an adjunct.

Our focus is on base beer style, subtlety, and balance — which can be achieved while still making a ridiculous beer and having a lot of fun. Regardless, some people truly love a big, pumpkin pie-in-the-face experience with their beer. So roast your pumpkin covered in maple syrup and smothered in spices, and add as much brown sugar and other spices to the kettle as you think you want. It’s pumpkin beer, after all, so feel free to go crazy.

We use canned pumpkins at a rate of 2 lbs. per barrel (about 1 oz. per gallon/7 g per L), which we add directly to the kettle with 10 minutes remaining in the boil.

At the same time we add the pumpkin we also add our first addition of pumpkin pie spices (a mixture of cinnamon, ginger, nutmeg, allspice, and clove), which are also added as a dry spice addition in the fermenter. I would suspect that our spicing rate is higher

than a traditional pumpkin beer, mostly due to the fact that our base beer is a 10.5% ABV imperial stout. We want to make sure the spices aren’t hidden.

If developing your own pumpkin imperial stout, I think it’s important to think about IBUs. Some imperial stouts have a rather high IBU and I don’t think that would work with Pumpkinator (which measures 34 IBUs) as the bitterness would get in the way of the pumpkin and spice flavor.

As a homebrewer, there’s the luxury of experimentation on such a small scale. Play with different pumpkin forms and different addition times. One of my favorite treatments when I was homebrewing was slightly roasting sliced pumpkins with brown sugar and cinnamon. If brewing 5 gallons (19 L), rack to 1-gallon (4-L) carboys and play with different spices to find the combination you like most.