Blubarb jam is a happy accident. The combination of fruits is not really that much of a stretch, inspired by strawberry-rhubarb jam, a classic, and blueberry-rhubarb pie, which has been taunting me from all corners of Pinterest and Facebook for the past few months. Truthfully, this jam was created as an attempt to stretch my first-of-the-year haul of blueberries; I love blueberry jam and hadn’t made any for more than a year, so was more than ready to restock the cupboard. In that respect, the accident was that blubarb jam worked out so gosh darn well, and tastes so flippin’ good, that I am a lucky little alchemist.
There’s no mistaking that blueberries and rhubarb were made for each other. As I mentioned, pie recipes are everywhere, and I spied some crumbles, cakes and cobblers in my browsing travels as well. Though I tweaked two of my own jam recipes (blueberry-lemon and strawberry-rhubarb) to come up with this combination, because I didn’t find any blubarb jam recipes I was happy with online or in my home jamming library, the recipe is pretty straightforward. I am going to tell you a little secret: the tartness of rhubarb is like a pedestal for the best aspects of other fruits to rest on in a jam. It’s true! Strawberries taste sweeter, cherries taste richer, ginger has more zing and blueberries taste brighter. This is where my words fail, because how does one describe the flavor of a blueberry? Whatever word(s) you would use, rhubarb amplifies that… blueberry-ness and makes this jam a winner. I can’t get enough. I foresee many batches coming out of my kitchen this summer, once local berries are in season; I have a stockpile of rhubarb in the freezer, ready to go. It’s lower in sugar than many traditional recipes and contains no pectin, and it’s relatively quick to make. My husband wants to try it as a filling for jelly donuts, and I think it would be a nice base for a barbecue sauce or pan sauce with roasted or grilled meat. I’m so very excited about all the possible ways to use blubarb jam; I would encourage you to make a batch so you can enjoy some, too.
Blubarb Jam (makes about 7 half-pints)
- 4 c. organic blueberries
- 6 c. rhubarb, washed and diced
- 4 c. sugar, separated
- zest of one lemon
- 1/4 c. lemon juice
- pinch of salt
Day 1: Place the blueberries in a large glass bowl and mash them roughly with a potato masher or similar. I left some whole but made sure that the majority of the berries were burst open. Mix in 1 c. sugar and leave them to macerate for at least 4 hours at room temperature, or overnight in the refrigerator. In addition to drawing the juices out of fruit, maceration seems to help soften the sometimes tough exterior of blueberries without having to blend or food process your blubarb jam to a one-note texture.
Day 2: Start a water bath and sterilize your jars and lids. In a jam pan, Dutch oven or equivalent, mix together the blueberries (with all of the juice they released and any undissolved sugar from the bowl in which you macerated them) and the rest of the ingredients. Bring to a rolling boil over medium-high heat; cook, stirring occasionally to prevent scorching, until the fruit softens and boils down to a nice, sticky, jammy consistency, about 13 mins. This information from Food in Jars is very helpful in determining set point, if you have questions; the pectin naturally found in blueberries helps the set in this blubarb jam quite a bit, so I have not had a runny batch yet, knock on wood. My own test of doneness is the way the jam coats my stirring spoon and drips off in sheets instead of waves; 13 mins. has been a reliable cook time for me, so far.
When you reach the set point, ladle hot jam into hot, sterilized jars; wipe the rims of each jar carefully and affix the lids. Process the jars in a water bath for 10 mins.; remove to a clear, towel-lined counter and allow to sit untouched overnight. Check that each jar is sealed; refrigerate unsealed jars immediately. Properly sealed jars will keep in a cool, dark cupboard for up to a year.