Silver Moon Brewing Co.’s latest release is a culmination of a year-long project involving bourbon and whiskey barrels, boysenberries and Baltic porter. The beer, Boysen the Wood, comes in two variants, aged in Crater Lake Spirits Rye Whiskey barrels and Oregon Spirit Distillers bourbon barrels, respectively.

The brewery originally planned to blend both versions into a single offering. However, according to its marketing description, “Once we tasted through these two sets of barrels, our team was impressed by the unique and tempting quality of both. It was clear that the original plan of blending them together would be the loss of a rare opportunity.”

Instead, the beers are offered in a two-pack highlighting the contribution of each type of spirit. (There is also a blended version, available on draft only at the downtown Bend pub.)

Head brewer Jacob Zuchowski formulated the recipe and led the project. “The beer was brewed from the beginning with the intention to go into barrels,” he said via email. “We wanted to use boysenberries so I felt a Baltic porter would have the residual sweetness to support the fruit and no real bitterness to compete with the fruit either (like a stout or barleywine might have).”

I also reached out to Jeff Schauland, who was Silver Moon’s head brewer at the time (and is now brewing in Virginia for Deschutes Brewery’s Roanoke tasting room). “We were able to secure barrels from both (Oregon Spirit Distillers) and Bendistillery (Crater Lake) so that they arrived about the same time. We thought that it would be fun to have two unique barrels with the same beer,” he replied. “Jacob did the bulk of (development) as we were transitioning jobs at that point.”

The beer spent nearly a full year in the barrels, allowing ample time to mature and soften any potential harsh flavors.

“The team had a really hard time deciding which barrels we liked more when we were selecting it for GABF,” Zuchowksi said. “I had the idea then to squirrel away four barrels of each to package off separately so people could experience the same thing.”

Baltic porters trace their roots to the regions around the Baltic Sea. The style evolved indigenously as local breweries emulate the porter and Russian imperial stout exports from England. It is characterized by higher alcohol, rich and sweet malt complexity, and a smooth and clean mouthfeel from lagering (cold fermentation).

Baltic porters are traditionally lagered, and many breweries ferment with a lager yeast, though fermenting with an ale yeast at colder temperatures is not uncommon. The lighter, cleaner palate achieved through lagering yields a flavor profile more akin to schwarzbiers than traditional porters.

Historically, Baltic porters were obscure and largely forgotten in the West during the 20th century due to the Cold War; the countries that brewed them were on the other side of the Iron Curtain. After it fell in the late 1980s, craft brewers rediscovered the style.

Many American versions are better classified as “imperial porters” as they are not lagered and tend to exhibit more bold, roasted flavors. Silver Moon’s version, however, was brewed true to style.

The brewery provided me with a bottle of each variant to sample. I started with the Oregon Spirit Distillers version; the barrels had held the distillery’s C.W. Irwin brand bourbon (now marketed as Straight American Bourbon), which I find to be a sweeter whiskey with oaky vanilla notes.

The boysenberry contribution to the beer is immediately detected in the aroma as a sweet, jammy quality that blends well with the sweet bourbon and charred barrel influence. That sweet whiskey character is more pronounced in the flavor, blending with elements of dark fruits, molasses, rye bread graininess, and oak. The boysenberries are less pronounced in flavor but are present towards the finish, reminiscent of a berry cordial.

Crater Lake Spirits’ Rye is crafted from 100 percent rye grain, which gives it a spicy, slightly smoky character with an impression of pepper. I find it to be “hotter” (more boozy, high-alcohol qualities) than Oregon Spirit’s bourbon.

This character is evident in the finished beer, as well; compared to the Oregon Spirit variant, this one is more spirit-forward, highlighting the rye spiciness in the aroma with a light berry cough syrup impression. This carries through into the flavor, emphasizing notes of tobacco, leather, mint, and black pepper, with a bit of dark chocolate-covered berry and sweet coffee at the end.

These beers are studies in contrasts, and inevitably you will find a preference between the two. When asked if he had a favorite, Zuchowski declined answering, not wanting to influence that outcome for others. “We spent a massive amount of time slowly hand packaging these products into separate bottles so people could share the experience of coming to that conclusion on their own,” he said.

— Jon Abernathy is a Bend beer blogger and brew aficionado. His column appears every other week in GO!