Every year, my garden’s first bumper crop consists of ruby-red rhubarb stalks. The prolific plants continue to thrive even when I start eating daily green salads and harvesting tomatoes by the box. I’ve developed many ways to enjoy the bounty, from my grandma’s classic rhubarb pie to the rhubarb kimchi in my pickling cookbook. I also use many stalks to flavor beverages.
I’ve already shared two of my favorite rhubarb add-ins for drinks in this column: Rhubarb-Vanilla Syrup and Strawberry-Rhubarb Shrub. Both play up sweet flavors as much as rhubarb’s natural tanginess when used in cocktails and mocktails. Here, I use less acid and less sugar to create a lighter seltzer with plenty of refreshing bite.
I typically make the concentrate for this seltzer as a by-product of homemade gari (sushi ginger), another recipe in my pickling cookbook. I prepare the ginger for pickling by blanching and draining it. The drained-off water holds plenty of gingery bite that balances what is otherwise essentially lightly sweetened rhubarb syrup.
If you would rather buy commercial ginger juice instead of blanching and draining sliced fresh gingerroot, taste the store-bought bottle’s contents first. Some brands are heavily sweetened with stronger ginger flavor, so you may need to adjust both the sugar and the ginger juice volumes in this recipe.
The combination of maceration and brief heat extracts the maximum amount of juice from dense rhubarb while retaining some of its fresh taste. Early-season stalks are usually the juiciest. To capture more bright flavor, let this young, tender rhubarb macerate a full day in the refrigerator, and then heat the pulp and released juices just until the sugar fully dissolves.
Rhubarb-Ginger Seltzer
Makes about 10 ounces of concentrate
For the concentrate:
1 pound rhubarb, sliced into 1/2-inch pieces (about 3-1/2 cups)
1/4 cup ginger juice, preferably from blanching fresh gingerroot
1/2 cup granulated sugar
1-1/2 teaspoons lime juice
For 1 serving:
1 ounce rhubarb-ginger concentrate
4 ounces seltzer
2 ounces white rum (optional)
Lime or lemon wedge for garnish
Combine the rhubarb, ginger juice and sugar in a medium saucepan. Cover the pan with its lid and let the rhubarb macerate at room temperature for about eight hours or overnight, until the sugar starts to draw out its juices.
Bring the rhubarb mixture to a boil over high heat, stirring occasionally. Reduce the heat to medium and cover the pan. Cook, stirring occasionally, for seven to 10 minutes, until the rhubarb softens. Let cool slightly.
Set a wire mesh strainer over a large glass measuring cup or bowl, and then pour in the rhubarb mixture and strain off the liquid. Stir the lime juice into the collected liquid. Let cool to room temperature.
For one seltzer serving, in a mixing glass, stir together the rhubarb-ginger concentrate, seltzer and rum, if desired. Fill a drinking glass with ice, pour in the flavored seltzer and garnish with a citrus wedge. Pour extra concentrate into a lidded glass bottle or jar and refrigerate for up to a week.
Julie Laing is a Bigfork-based cookbook author and food blogger. Learn more about this month’s cooking workshops at TwiceAsTasty.com.