On blazing hot summer days, a big blue oasis can be found parked in the Flatiron District. Named for the thermodynamic scale that expresses absolute cold, Kelvin Natural Slush Co.’s industrial-grade slush machines churn out cups of frosty goodness in spicy ginger, puckery citrus, and a mellow mixture of green and black tea. The lightly sweetened base slushes are then customized with a rotating menu of mix-ins—fresh chopped mint and basil, and seasonal fresh fruit purées including white peach, guava, and caramelized pineapple. All the brain-freeze bliss you remember from childhood (sans the high-fructose corn syrup and tongue-tinting Red 40 dye).
Owner Alex Rein loved slushes and slurpees as a kid, but at a certain point he stopped drinking the sugar-laden, truck-stop staples. “The thing is slushes can be really refreshing. They aren’t as heavy as a milkshake.… I wanted to offer a lighter, more grown-up version.” He began dreaming of a more sophisticated, crave-worthy slush while working as a corporate attorney, brewing up batches of tea and ginger beer in his apartment kitchen then freezing and blending them to create the recipes that ultimately became their three signature drink bases.
With less than two months of street experience, Kelvin Slush was the decided dark horse at the 2010 Vendys against a field that included The Big Gay Ice Cream Truck (page 184) and The Dessert-Truck (page 188)—both established vendors with massive followings. The scorching late September heat on the day of the awards made for ideal conditions to showcase their chilly treats and when the last vote was counted, the people had spoken. The newbies from Kelvin took home the coveted Dessert Vendy title and cemented their reputation in the foodie community as a summer-must.
With their fan base secured, it wasn’t long before Kelvin took the next step in sophisticated slushie-dom: frozen cocktails. While New York’s open container laws prevent Kelvin from bringing boozy slushes to the streets, Alex’s business partner, Zack Silverman started noticing some rogue behavior from their customers “People would show up at our truck with flasks and mini-bottles all the time to make their own, what we call, ‘prohibition style’ slush on the street.” In 2012 they launched a restaurant and bar partnership program working with select restaurants and bars to offer Kelvin “frozen cocktails.” Now you can get boozy slushes at some of the coolest spots around the city or make your own Kelvin-style cocktail from the comfort of your own home.
Refer to these handy icons before tackling the recipes:
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Adapted from Alex Rein’s recipe
Traditional Dark and Stormy® cocktails while the call for ginger beer, this frozen rendition uses a home-brewed, spiced syrup. Kelvin Slush owner Alex Rein recommends splurging on a top-shelf dark rum like Gosling’s Black Seal® Bermuda Black Rum. This drink gets its rich molassesy-flavor from cane sugar, an unrefined sugar. If you can’t find cane sugar or an equivalent like panela, use dark brown sugar.
“When I’m on the truck I’ll have at least one slush a day. It’s hard to resist when you have the machines right there.”
½ cup cane sugar like panela or dark brown sugar
1 piece (approximately 4 inches long) fresh ginger, peeled and roughly chopped into approximately ½ x ¼–inch pieces
8 cloves
1 star anise
½ cup dark rum
cup fresh lemon juice (about 2 lemons)
8 cups ice
In a small saucepan bring ½ cup water to a low simmer over medium heat. Add the sugar and stir until it dissolves. Add the chopped ginger, cloves, and star anise. Remove from heat and steep uncovered for 25 minutes. Strain syrup mixture into a small bowl or airtight container, squeezing out as much liquid as possible from the ginger, cover and chill the syrup in the refrigerator for at least 20 minutes.
Add the spiced ginger syrup, rum, lemon juice, and ice to a blender. Blend until smooth. Serve in lowball glasses.
Adapted from Alex Rein’s recipe
This bright and light julep is perfect for Derby Day or any summer day. The recipe will work well with your favorite bourbon. Kelvin Slush owner Alex Rein personally favors Knob Creek®.
½ cup granulated sugar
½ fresh lemon, sliced as thick rounds
cup fresh mint leaves (about 40 leaves), divided, plus additional for garnish, if desired
½ cup bourbon
cup fresh lemon juice (about 2 lemons)
8 cups ice
In a small saucepan, bring ½ cup water to a low simmer over medium heat. Add the sugar and stir until dissolved, about 2 to 3 minutes.
Remove mixture from heat and add the sliced lemons (do not squeeze lemon juice) and 30 mint leaves. Steep mixture uncovered for 10 minutes.
Strain into a small bowl or airtight container (squeeze out as much liquid as possible from the lemon and mint). Cover and chill strained syrup in the refrigerator for at least 20 minutes.
Add the lemon mint simple syrup and remaining mint leaves to blender. Blend until mint is finely chopped.
Add the bourbon, lemon juice, and ice to blender. Blend until smooth. Serve in lowball glasses garnished with fresh mint leaves, if desired.
