Homemade strawberry rhubarb jam is a delicious spread for toast, yogurt, or dessert recipes. Thanks to the low-sugar recipe, this jam tastes fresh and bright, just like real fruit.
Prep Time20 minutesmins
Cook Time30 minutesmins
Total Time50 minutesmins
Course: Canning
Cuisine: American
Keyword: rhubarb jam recipe, rhubarb strawberry jam
Prepare water bath canner by filling it halfway with water, and setting it on the stove. Turn the burner to high. Once it reaches a boil, reduce it to simmer. You want to keep the water hot so that everything is ready when the jam is.
Wash and clean your jars. Fill with hot water or keep them warm in a clean dishwasher or oven.
Wash your lids and set aside in clean place.
Making the Jam
Rinse the strawberries. Remove the tops, cut in half or quarters, and place in a large bowl.
2.5 cups strawberries
Gently mash with a potato masher or pastry cutter until it yields 2.5 cups of mashed berries.
Add the clean chopped rhubarb to a heavy-bottomed saucepan with 1/2 cup water.
4 cups chopped rhubarb, 1/2 cup water
Cook on medium heat, stirring often until the rhubarb softens.
Stir in the strawberries and continue to cook the mixture until the fruits are well-combined.
In a small bowl, combine 1/2 tsp calcium powder from the Poman's Pectin box with 1/2 cup cool water to create calcium water.
1/2 cup cool water
In a separate bowl, combine 1.5 cups of sugar and Pomona's pectin. Set aside.
1.5 cups sugar, 3 tsp Pomona's Pectin
Add 2 tbsp lemon juice and calcium water to the pot with the rhubarb and strawberries, stir.
2 tbsp bottled lemon juice, 3 tsp calcium water
Add the sugar/pectin mixture, and bring to a gentle rolling boil.
Stir constantly for 3 minutes, turning down the burner to medium if the jam starts popping.
Remove from heat and continue stirring for 5 more minutes. At the end of the 5 minutes, remove any foam that remains.
At this point, turn the burner under the canner back up to high and get that water boiling again.
Canning the Jam
Using the funnel and a ladle, add the jam to your prepared jars, leaving 1/4 inch of headspace at the top. Headspace is the amount of room between the top of the food, and the rim of the jar.
Using a wet clean rag, wipe the rim to make sure there isn't any sticky jam on there.
Place a clean lid on the jar and then a ring. Tighten the ring to fingertip tight.
Using canning tongs, gently place your jars in the canner. Put the lid on, and set your timer. Pro tip: the water must return to a boil in the canner before you can start the timer.
Process half-pints and pints based on the elevation guide below:*0-1,000 ft – Half-Pints &Pints =5 min *1,001-6,000 ft – Half-Pints &Pints =10 min *6,000 ft+ – Half-Pints &Pints =15 min
Once the jam has processed for the appropriate amount of time, remove the canner from the burner, and carefully remove the lid of the canner (Pro tip: use oven mitts to take the lid off because the steam is super hot).
Using canning tongs, carefully remove the jars, and place them on a thick towel in a place where they can be undisturbed for 12 hours.
After the jars have rested for about 12 hours, press down in the middle of each lid. If it "gives" at all, the jar didn't seal. Either enjoy it that day, put it in the fridge, or reprocess it.
Once the jars have sealed and cooled, remove the rings. Label and store sealed jars in a cool (best results are 50-70˚F) dark place for up to 12-18 months.
Notes
Makes 5, 8 oz jars.
If you prefer a tarter strawberry rhubarb jam, use 2.5 cups of cooked rhubarb and 1.5 cups of mashed strawberries.
Jam is best when made in small batches. Avoid doubling or tripling the recipe.
Will last for 1 month in the fridge or 12 months sealed and at room temperature.