This blueberry-rhubarb jam recipe is lower in sugar than most jam recipes, calling for only 2 cups for a five (8-ounce jar) yield, as opposed to most 4-cup-sugar recipes. This jam gets a little kick from lime zest and juice and would make a great food gift. You must let the rhubarb stand with the sugar overnight to soften it, so bear that in mind when making this recipe.
This jam does not need to be canned but must be refrigerated (up to 3 weeks) or frozen (up to 1 year). Remember to label each container with the name of the jam and the expiration date. If you decide to process this jam in a water bath for room-temperature storage at 55 to 70 degrees (up to one year).
- 21 ounces rhubarb, washed and chopped 1/2-inch dice
- 1 1/2 cups sugar
- 1 1/4 cups water
- 2 1/2 tablespoons (half a 1 3/4-ounce package) powdered pectin for low-sugar or no-sugar recipes
- 1/2 cup sugar
- 10.5 ounces blueberries, washed and stemmed
- Zest and juice of 2 ripe limes
- 1/4 teaspoon butter (to prevent foaming)
In a medium nonreactive bowl, combine rhubarb and 1 1/2 cups sugar. Cover with plastic wrap and let sit on the counter overnight.
In a large saucepan or pot, combine water, pectin, and 1/2 cup sugar. Stir in blueberries, reserved rhubarb, and its juices, lime zest, lime juice, and butter. Bring to a full rolling boil over high heat, stirring constantly, 1 minute. Remove from heat. Skim off any foam that has risen to the surface.
Ladle hot jam into five heatproof or canning jars that have been washed in hot soapy water (sterilizing isn't necessary unless the jam will be canned), rinsed and air dried. Top with lids and rings that have been washed in hot soapy water, rinsed and air dried. Turn upside down onto a clean dish towel.
When cool, turn right side up and refrigerate for up to three weeks or freeze for up to 1 month. If you decide to can the jam for room-temperature storage up to one year, read the note below.