Sumac’s Back

The ‘nautiest among you will recall last year’s sumac beer, which featured freshly harvested sumac from the fields surrounding Four Star Farms. The beer, dubbed “Field Day”, turned out delightfully tart and refreshing. It has since become a subject of discussion among taproom patrons who often ask when we’ll have it again. As August draws to a close, we are happy to say that more Field Day is now on tap!

Getting the good stuff

As with any experimental, ingredient-driven beer, we brew, learn and repeat. Last year, we were thrilled that a handful of volunteers showed up with sleeves rolled, ready to drive out to Northfield with us and harvest sumac. It took several hours and the help of some long, telescopic loppers to gather enough sumac for a full brewery-scale batch. We drove back with the haul, which another eager team of volunteers helped us break apart into its constituent furry berries.

To get the sumac flavor out of the berries, we did a hot steep and mash, and then ran off the concentrated tea right into the kettle during the boil of its host pale ale. Once the beer was fermented, we tasted it and were left wanting even more sumac flavor. So, we ended up making another few gallons of sumac tea from another harvest, boiling it to pasteurize, and adding it to the batch. This topped off the flavor to our liking. The next obstacle we faced was removing the cloudiness. Apparently, the presence of many proteins extracted from the sumac created a haze in the beer. We tried several methods to reduce this haze, but were minimally successful. So, we just served the beer au naturel. It was a hit! Something totally unique and delicious. We resolved to do it again when the sumac season next rolled around.

This year, we asked ourselves how to improve the beer. Obviously, we wanted even more sumac flavor, since we had to top it off last time. One way to achieve that is to gather more sumac. However, we also noted that sumac from earlier in the season would be fresher and stronger in flavor and acidity. So we moved our picking time up by a full month, from early September. This year, we resolved to pick the sumac in early August after a dry period. We scouted out the plants in advance, noting the differences between male, which would never fruit, and female, which would provide us large clusters of the berries we wanted. We also anticipated how difficult it would be to harvest from taller plants, so we located a cache of sumac plants on the opposite side of Four Star Farms.

Good ol’ fashioned sumac-pickin’ bee

Another big difference was the number of people we brought out to Four Star this year. August 8th was our first ever Field Day: a festival celebrating farm and brewery and food collaboration. Over the course of the day, we entertained around 500 people who enjoyed the farm, toured the hop yards, drank Aeronaut ales, and enjoyed the sounds of some 27 bands. During this festival, I took two teams of willing participants out into the fields to help harvest some staghorn sumac for this year’s Field Day beer. In total, over the course of a few hours, about 20 helpers collected a total of 27% more sumac than last year. Between that and the improved quality of the early harvest, we were on track for success!

Sumac mash

Brew day: the sumac was staged, and me, Dan and Sean were all prepping the sumac berries while Mark was finishing the mash for the brew. We stuck with our hand-mashed berry method this time, but we elected to make an additional improvement. We wanted to reduce extraction of tannins and excess proteins from the sumac, so we reduced the temperature of the steeping liquid to room temperature. This still allowed us to extract a ton of water-soluble elements from the sumac with the help of vigorous agitation, but reduced tannin extraction. We also figured this would reduce the amount of haze in the final beer.

Another change we made was to extract the sumac tea prior to adding it to the boil. This way, we could add it more rapidly and have a more precise boil time. We measured the pH of the sumac tea concentrate and it reached 2.8! Considering it was the same volume of liquid as last year’s sumac tea, we were thrilled to see it lower than last year’s pH of 3.0. Now remember, we are working on a logarithmic scale here, so this difference represents more than a 50% increase in acidity. Needless to say, we were excited. Of course, this concentrated sumac tea was all diluted in the beer, so the pH of the beer was nowhere near this low, so you’re safe…for now.

Adding the sumac extract

After a quick and vigorous fermentation, the beer was ready. This time, the sumac flavor came through loud and clear from the beginning. The beer also turned out less cloudy than last time. One other difference was that this year, less of the red color was extracted. So the beer doesn’t have the same hue as last year’s. Perhaps next year we’ll do a blend of hot and cold steeps. Or a CO2 extraction.

All in all, this beer was very labor-intensive, but since it’s a labor of love, the beer is full of love. Peace, love and sumac beer!