There is something about the combination of rhubarb and rosemary that speaks to me. The bright, apple-y flavor of rhubarb just seems to call out for the woodsy herbaceousness of rosemary and I am always happy to help them come together. This pretty jelly is entirely magical when eaten with fresh spring cheeses.
1 pound bright red rhubarb, chopped
1 to 2 sprigs fresh rosemary, divided
1½ cups sugar
1 tablespoon powdered pectin
Combine chopped rhubarb, 1 large sprig of rosemary, and 1½ cups water in a pot, cover, and simmer together over medium-high heat for 20 to 25 minutes. Cook until the rhubarb has completely broken down and the water is tinted a vivid pink.
Line a fine-mesh sieve with cheesecloth and place it over a large bowl. Pour the cooked rhubarb through. Let it sit and drip for at least half an hour. Do not press the rhubarb pulp, as that will make your jelly cloudy. When the rhubarb juice is finished dripping through the sieve, discard the solids and measure out two cups of rhubarb juice.
Prepare a boiling-water-bath canner and 3 half-pint jars. Place canning lids in a small saucepan of water and set to the barest simmer. Measure out the sugar and whisk the powdered pectin into it so that they are fully integrated.
In a large, nonreactive pot, combine the rhubarb juice and the pectin-spiked sugar. Once the sugar is dissolved, taste the rhubarb juice to determine level of rosemary flavor. If you like it as it is, proceed with cooking. If not, add an additional rosemary sprig. Bring to a boil and cook, stirring frequently, until the volume in the pot is greatly reduced.
While you continue to stir, clip a candy thermometer to the pot and watch until the pot reaches 220°. There will be a great deal of foaming and bubbling before it reaches this point. It should look thick and syrupy and the bubbles should look glossy.
When jelly is finished cooking, pour it into prepared jars. If you added additional rosemary, remove it at this time. Wipe rims, apply lids and bands, and process in a boiling-water-bath canner for 10 minutes.
Adapted from Marisa McClellan’s new book Preserving by the Pint: Quick Seasonal Canning for Small Spaces (Running Press).