This recipe comes from The New York Times by way of the ever-resourceful reader Naomi. It’s fascinating stuff…if only I can figure out where to get cinchona tree bark!
4 cups water
1/4 cup (1 ounce/20 grams) cinchona bark, powdered (use a coffee grinder)
1/4 cup citric acid, also known as lemon salt
3 limes, only the peeled zests
3 lemons, only the peeled zests
1 grapefruit, only the peeled zests
1 cup chopped lemongrass (3-4 stalks)
9 whole allspice berries
6 whole cardamom pods
1/4 teaspoon kosher salt
1 tablespoon lavender
3-4 cups rich simple syrup (by volume, two parts sugar to one of boiling water, stirred to dissolve)
In a covered saucepan, bring all ingredients except the simple syrup to a boil and reduce heat immediately; simmer on low for a half hour, then remove from heat and allow to cool fully. Transfer to a carafe or jar and chill for two days. Strain through a superfine chinois or cheesecloth, or by using a plunger press coffee maker. Return to the carafe and refrigerate for a day or two, allowing sediment to accumulate on bottom. When the layer of sediment seems stable, gently decant off the clearer liquid without disturbing the sediment “mud.” It should be about 3 cups at this point (I was closer to 2 1/2); add to this liquid an equal measure of simple syrup, mixing well. Funnel into a clean, cappable bottle and refrigerate. Makes roughly 6 cups or 1.5 liters.