I’m from a whiskey and rum background, and when I came here from Privateer, I very much had rum on the mind—I love rum as a spirit. I have an appreciation for American rum and the way you can make rum in a cooler North American environment, and I also love being able to use our rum casks afterwards for single malt maturation.
But we also realized there were no Kosher for Passover rums on the market, and there’s no reason rum couldn’t be a KFP product.
We decided at Thornton to go for more of an American flavor profile, where it’s more for bourbon drinkers with those huge, brand-new charred and toasted oak casks, rather than previously used casks. That was a little bit different, kind of made for the Barbados style—fairly robust, but not super-estery like Jamaican style—though we’ve done a little bit of that since.
A lot of American rum is too much like bourbon—too oaky—and I think with rum you need to work to create a balance between the distillate and barrel character. It’s important to be able to choose casks that aren’t too active and aggressively tannic, allowing your spirit to really shine. As a personal preference, I distill to a lower proof when I make rum. I wanted to go with something that had a little more body and a little more natural sweetness.
The way we distill is a lot less efficient. But we found that what we’re doing is what our customers really like—and that’s also what I love to drink and make, as well.
We do a double distillation for the rum. I’m a big fan of double distillation; I find I have more control over the spirit character without having to go very high on your proof.
We do a pot distillation first with our 500-gallon pot still. We take our fermented wash, strip it and end up with 28–30 percent alcohol. From there we do a final distillation on a pot-column hybrid that has four plates. You’re not going to get a very light, high-proof spirit on this system, this approach creates a spirit with more body and richness, which for us is really important because we’re not interested in adding any sugar post-distillation, which is very common in the rum world but just isn’t our jam.
After we launched the rum, the following year we decided to make a Kosher for Passover gin and a vodka. We take a lot of pride in our year-round gin and really like to focus on botanical spirits, but we also realized that this was also a gap in the KFP market.
Spirits for Passover
Our Kosher for Passover spirits are sold and consumed eight days of the year for the most part—it’s an interesting product. We’re trying to line it up as a short window for a pretty significant community.
It’s very stringent, from a supervision standpoint. Every ingredient we work with has to be approved by the rabbis. We have to kasher the place—that means cleaning every piece of equipment with boiling water and then shutting down everything else. And then every aspect of production has to be performed under direct supervision. I’ve actually come to embrace it as a really healthy exercise because it forces you to pay even more attention to every detail of the process than you already were.
Challenges for certification include anything grain-based, whether it be the equipment itself—or, if you’re making dark rum in the traditional Caribbean sense with used American whiskey casks, that would be a problem. So, we use all brand-new casks for this. Yeast nutrients, processing aids like citric acid—really anything that you can think of that comes into contact has to be vetted and usually has to have its own Kosher for Passover certification for us to be able to use it.
The bulk of these products goes to our distributors in New York and New Jersey. We’re also sending it to Florida and Southern California and here in Chicago. The independent bottler Single Cask Nation has also choses standout single casks each year to ship nationally.
Rum Challenges in Chicago
Fermenting rum in the dead of winter in Chicago, when you’re limited in terms of nutrients, is a huge challenge.
Rum can be tricky to ferment; it tends to favor a warmer environment. Looking at my thermometer inside, it’s 46°F (8°C), so it’s kind of working a little bit against how rum is traditionally made.
At lower temperatures, yeast are going to struggle—they’re going to lag, and it can take a lot longer. We do several-week ferments, and they tend to work slower. You have to be more conscientious of the pH because it does drop very quickly, and that will stall fermentation. You want to try to have a robust fermentation from the beginning. The lowest I think we seem to be okay at is about 61°F (16°C); I try to keep it closer to 68°F (20°C).
However, that also allows us to focus on an interesting approach. At higher temperatures, you’re going to get more ester production. At colder temperatures, you get more raw ingredient flavor coming through. It’s not as robust or ester-forward, and that’s kind of a cool way to go and a huge departure from Caribbean or Latin American rums.
This colder cask maturation also allows for very specific flavors to develop. I get what I like to call “specificity,” where different barrels take on very specific flavors, and it’s kind of cool because it gives me a bunch of things to put together, to collect. Rather than choosing from every barrel that you like as a spec, it’s, “How do we work together to create something more interesting than each individual barrel?”
Single Malt Focus
I got into this building with the intention of doing single malt whisky—this is the thing I’m most passionate about and really studied when I did my masters over in Scotland. We wanted to release the Dead Drop lineup while the single malt was maturing, to be able to make other products that we were really interested in.
We’ve been developing single malt for the last six years, putting down barrels that have been maturing. I really don’t want to rush it.
Around the world—whether it be Scotland, Ireland, Japan, Australia—producers realize that single malt expresses very well in cooperage that is not aggressively oaky. So, we let the spirit shine and show its character. To that end, we use ex-bourbon casks, ex-rye barrels, ex-rum casks. Some are also in low-char, toasted, new oak barrels, which are intended to be used as a blending tool, not to overpower the spirit.
We also do some interesting one-off expressions with local cideries and meaderies. I’ll give them one of our barrels to mature say an interesting honey variety, then bring it back to mature our single malt in it.
We use our own barrels as much as possible. With the ability to dump a barrel in the morning then fill it with fresh, new-make spirit in the afternoon, we’re able to control the life cycle of that barrel, the quality of it, and get it when it’s very fresh and still has a lot on it. I get really excited about that.
Compared to how things work in the Scotch whisky industry, where the bourbon barrel will be broken down, put on a ship and sent overseas—which may take months—it’ll be bone dry, it has to be re-coopered, treated, and filled with water before it can be used for spirit maturation.
Making Peated Single-Malt Whiskey in Illinois
We’ve been working with sources in northwestern Illinois, on the banks of the Mississippi River, to hand-harvest local Illinois peat.
We then bring that down to Sugar Creek Malt in Indiana, who we work with exclusively on 100 percent of our malt. They used it to smoke a lovely pilsner malt for us. Then I take that back and mash it, do a long fermentation in wine fermentors, then double pot-distill it to create the spirit.
It’s fascinating if you think about what Illinois and American Prairie terroir might mean, and what this area used to be like before people started planting corn and soybeans. This is all prairie land—what we had here was wildflowers and prairie grass. And that’s really the makeup of the peat that we use—it just comes through in the flavor profile.
It’s not super phenolic. I didn’t want to go with a smoke-bomb style, although I think there is a place for that. I love some of those but we wanted to allow the plant matter to come through more than the ashy, creosote sort of smoke. So, we decided to cold-smoke our pilsner malt. It’s a more delicate process, and it can take up to three days. It contributes more of the delicate floral and grassy character to the spirit. It’s worked out beautifully, and we love how it is maturing.
It’s been aging four years at this point, and it’s exclusively matured in ex-bourbon barrels. I think ex-bourbon barrels are the best way to have a kind of bright canvas for maturation if you really want your raw ingredients and your spirit and house character to shine through. I think it would be such a waste to take this spirit, with these beautiful raw ingredients that we put so much time and effort into procuring and then put that into a No. 3 or 4 charred oak barrel.
Instead, we want something that’s going to be a blank canvas and allow the spirit to mature in a more delicate way. It takes more time to reach maturity, but the top-notes that we get are just really lovely.