Blueberry Rhubarb Jam

A low sugar type made with a calcium setting pectin product called Pomona's Pectin.

Rhubarb is not traditionally a fruit used in jam or jelly but you might find strawberry rhubarb jam or pie. Rhubarb is pink in color and softens when cooked. Rhubarb is quite tart and blueberries are more alkaline, they balance each other nicely. Blueberries have a lot of fibrous skin which makes an all-blueberry jam kind of too thick - too much pectin-y goodness. Rhubarb balances nicely with the texture too as it becomes more sauce like when cooked and loses the celery like shape.

Chop the rhubarb as if it were celery, compost the leaves. For strawberry rhubarb pie, chop the celery in one inch pieces / strawberry size. Rhubarb is a biennial plant that will grow indefinitely if you prevent it from flowering. It isn’t a pretty flower anyway. The stalks can be harvested all summer long and are good in soup too, as a celery replacement. It is a VERY HIGH oxalate food so avoid it if sensitive. Or cook it in water and discard the water before adding it to another recipe. Photo by Monika Grabkowska on Unsplash

Pomona’s Pectin Brand gels with the help of calcium dissolved in water.

Blueberries are a low acid fruit that are used in jam but lemon or lime juice is recommended with the pectin that I used. Rhubarb is acidic and the combination made a tangy balance that jelled nicely. This was a double batch, based on the directions given with the pectin. A recipe using rhubarb was not included in the box of Pomona's Universal Pectin but their website has several variations that do call for some additional lemon juice. My version tastes good and jelled without lemon juice.

• Pomona's Universal Pectin home page: [pomonapectin] Recipe pdf: [pomonapectin] The pectin is derived from citrus peel and its jelling power is activated by calcium rather than sugar. Sugar free jams and jellies or low sugar varieties can be made more easily with this type of pectin than with standard pectin. Traditional jelly recipes may use 7 cups of sugar per 4 cups of fruit.

The advantages of picking your own blueberries, is eating some too. Late July to early August tends to be blueberry season. Photo by Mario Mendez on Unsplash

Blueberry Rhubarb Jam (double batch)

In a 2 quart saucepan, mix the berries and chopped rhubarb with part of the sugar, reserve some sugar for mixing with the dry pectin to add at a later stage.

• 4 cups blueberries

• 6 cups chopped rhubarb (this measurement was the raw product - 4 cups mashed/cooked was needed)

• 1 cup cane syrup and 2 cups powdered sugar (cleaning out my cupboard - swap 2-3 cups regular sugar or sweetener of your choice)

• 2 teaspoons calcium water mixture

  • Follow Pomona’s package directions for different types of fruit regarding the amount of calcium water to use and if extra lemon juice is needed. Fruit varies in pectin and acidity both of which can affect how thick or thin the cooked jam will be. If rhubarb wasn’t in this batch, and it was just blueberries, then lemon juice or apple cider vinegar would have been needed too. The Pomona’s package insert has recipes for a variety of fruit types.

Cook for about 10 minutes or until the rhubarb is softened.

• Disperse the pectin in some of the recipe’s sugar so it will mix evenly when added to the cooking fruit: 1 cup white sugar --- mixed with 4 teaspoons Pomona's Pectin

• Add the pectin/sugar mixture to the boiling fruit while stirring. Continue to stir for 1-2 minutes and then remove from the heat and ladle into sterilized jelly jars for canning.

Low sugar jams and jellies should not be preserved with the melted wax seal method. Sugar itself acts as a preservative when it is in greater concentration than other nutrients. The lower sugar jams and jellies should be sealed by pressure canning or stored in the refrigerator or freezer.

Once opened if the jam had been sealed, store in the refrigerator and use within a few weeks or month. Low sugar jams are more perishable than high sugar jams (7 cups sugar for 4 cups of fruit is a typical ratio) Watch for mold on the surface of the jam or jar. Wiping the jar rim occasionally can help prevent molding at the top. Mold isn’t a deadly food poisoning risk but can give people mold allergy symptoms. If pressure or hot-water bath canned, watch for bulging tops, and discard the jar if that occurs - it might indicate botulism risk.

• USDA, Principles of Home Canning, pdf [nchfp.uga.edu]

Once you start making jams and jellies you may not want to stop - except to eat! Photo by Barbara Chowaniec on Unsplash

Other jam recipes that incorporate medicinal citrus peel and pomegranate pith are in this post - I kept adding new variations to the same post, and it has a chocolate ganache made with some of the citrus peel plum jam and that was divine.

Disclaimer: This information is provided for educational purposes within the guidelines of Fair Use. It is not intended to provide individual guidance. Please seek a health care provider for individualized health care guidance.