This easy plum jam recipe makes a small batch without pectin that you can easily can in a water bath on the stove. Feel free to make it plain, or you can flavour it with cinnamon or even Earl Grey tea leaves.
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Jams to make in the summer
Summer calls for making preserves. Each month, focus on one fruit and by the end of the summer, you'll have a rainbow of jams to enjoy year-round:
- In the early summer months, the most obvious jam to make is rhubarb jam (no pectin) and also honey apricot jam
- Mid summer, focus on the berries, like this strawberry red currant jam and this blueberry jam
- At the end of the summer, make this spiced apple jam and the plum jam featured here
Steps for perfect plum jam
Plum jam is easy. Here's a breakdown of the steps:
- Prepare the fruit, washing and drying it, then chopping it into small pieces.
- Macerate the fruit, mixing it with sugar, which draws out the water and helps break down the fruit so that your jam will boil quickly and the sugar will be all dissolved.
- Boil the jam until you reach the jam setting point. You can use a thermometer to help judge the set, but also a frozen plate test. It's just like determining the marmalade setting point so watch the jam as it boils: the bubbles will be more stable when you approach the perfect set.
Ways to flavour plum jam
Plum jam is great plain, but why not try infusing it? You can infuse it with your favourite tea or spices, like cinnamon or cardamom.
Adding spices like cinnamon yields a plum jam that tastes like plum pie filling. It's amazing the flavour you can get out of just one cinnamon stick.
Canning tools to make your jam-making easier
Don't forget, if you are afraid of home canning, or if you don't have the proper tools, I have product reviews on the blog for a home canning starter kit that you can purchase from Amazon to get you going (tool kit on Amazon & starter kit from Bernardin on Amazon). Make sure to have a probe thermometer to take away the guessing of when the jam is cooked enough. I own a pink Thermapen which is very fast at registering temperatures and temperature changes, but the Thermoworks Dot can be used hands-free so would be more appropriate here.
The basic plum jam recipe is adapted from Camilla Wynne's book Preservation Society Home Preserves (available on Amazon).
I like to use a thermometer when I boil a batch of jam: the thermometer allows you to monitor the temperature of the jam, thus ensuring you achieve a high enough temperature so your jam will set when it cools. This is the jam setting point. You can also use the plate test (also known as wrinkle test) by dolloping jam on a frozen saucer.
- 1.25 kg (2¾ lb) Italian plums pitted and diced
- 450 g (2¼ cups) granulated sugar
- 65 mL (¼ cup) fresh lemon juice
Flavour options (choose one or the other, or neither)
- 1 cinnamon stick optional
- 22.5 mL (1½ tablespoon) loose leaf Earl Grey tea optional
- In a medium bowl, combine the chopped plums, sugar, lemon juice and flavour (either a cinnamon stick OR the Earl Grey tea leaves wrapped in a cheesecloth to form a make-shift tea bag). Stir everything together and let rest on the counter for 6 to 8 hours, stirring every so often. The juices from the plums will form a syrup with the sugar as it dissolves.
- At the end of the day, stir once more and then cover with plastic wrap and chill overnight.
- The next day, transfer the macerated plum mixture to a large pot and heat on medium–high to bring it to a boil, stirring often.
- Skim off any foam as needed and continue to boil/stir until the jam has thickened (I boiled one batch to 215ºF and the other to 217ºF). The jam is probably thick enough when it starts spitting at you.
- Remove the cinnamon stick or the Earl Grey tea bag from the pot. Transfer the hot jam to hot, sterilized 250-mL mason jars using your handy canning tool kit available on Amazon, leaving ¼" headspace. Cover with clean, sterilized snap lids. If a jar isn't filled full, put it in the fridge to enjoy right away.
- Process in a large boiling water batch for 5 minutes, then leave them another 5 minutes, still in the canning pot but off the heat before transferring the jars to a clean towel on the counter.
- Let the jars rest overnight before labelling and storing them.