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Homemade Plum Jam: A Taste of Summer Preserved

The memory of my grandmother’s sun-drenched kitchen always floods back when I smell plum jam simmering. Each year, her ancient stove would become the heart of a fragrant operation as she transformed baskets overflowing with purple and red plums into jars of glistening ruby goodness. I remember watching, mesmerized, as she carefully ladled the hot jam into sterilized jars, her hands moving with a confidence born of years of preserving summer’s bounty. Now, carrying on her tradition with plums from my own small tree, I find myself connected to her, and to summers past, with every batch I make.

Recipe Overview

Prep Time: 30 minutes
Cook Time: 45-50 minutes
Total Time: 1 hour 15 minutes
Yields: 6 8 oz jars
Dietary Type: Vegan, Gluten-Free

Ingredients

6 cups ripe plums, crushed (Japanese Santa Rosa plums work wonderfully)
6 cups sugar
1/4 cup lemon juice
1 teaspoon cinnamon

Equipment Needed

Large, deep pot (stainless steel or enamel-coated is best)
Food processor, chopper, or blender
Canning jars (8 oz or half-pint)
Canning lids and rings
Canning jar tongs
Wide-mouthed funnel
Large pot for water bath canning
Jar lifter

Instructions

Begin by preparing your plums. Wash them thoroughly and remove the pits. There’s no need to peel them, as the skins add color and pectin to the jam.
Crush the plums using a food processor, chopper, or blender. Pulse until you reach your desired consistency. It’s perfectly fine to have some small chunks of fruit remaining for added texture. Don’t worry if there’s some foam produced during this process.
In a large, deep pot, combine the crushed plums and sugar. Stir well to ensure the sugar is evenly distributed.
Over medium heat, slowly bring the mixture to a boil. Stir frequently, especially at the beginning, to prevent the sugar from scorching on the bottom of the pot. It is important to bring the mixture to a temperature of 220 degrees Fahrenheit (104 degrees Celsius). A candy thermometer is helpful for monitoring the temperature. Slow heating will also help reduce foaming.
Once the jam reaches a full, rolling boil (one that continues even with stirring), boil for 15-20 minutes, continuing to stir frequently. Watch carefully to prevent boil-over.
As the jam boils, you will notice foam forming on the surface. Use a spoon to skim off the foam and discard it. This will result in a clearer, more appealing final product.
While the jam is boiling, prepare your canning jars and lids. Place the jars in a large pot of boiling water, ensuring they are fully submerged. Boil for 10 minutes to sterilize them. Place the lids in a separate saucepan and simmer in hot water (do not boil) to soften the sealing compound. Keep the jars and lids hot until ready to use.
Once the jam has reached the desired consistency (see “Expert Tips & Tricks” below), remove the pot from the heat.
Using a jar lifter, carefully remove a sterilized jar from the hot water and place it on a heat-resistant surface.
Place a wide-mouthed funnel into the jar. Ladle the hot jam into the jar, leaving 1/4 inch of headspace (the space between the top of the jam and the rim of the jar).
Wipe the rim of the jar with a clean, damp cloth to remove any spills or drips.
Using a magnetic lid lifter or clean tongs, place a sterilized lid on top of the jar, ensuring the sealing compound is in contact with the jar rim.
Screw a ring onto the jar, tightening it fingertip-tight (not too tight, as this can prevent proper sealing).
Repeat steps 9-13 with the remaining jars, jam, lids, and rings.
Place the filled jars in a large pot fitted with a rack. Add enough hot water to the pot to cover the jars by at least 1 inch.
Bring the water to a rolling boil and process the jars for 10-15 minutes. Adjust processing time for altitude (add 1 minute for every 1,000 feet above sea level).
After processing, turn off the heat and carefully remove the jars from the water bath using a jar lifter. Place the jars on a towel-lined surface, ensuring they are not touching each other.
Allow the jars to cool completely undisturbed for 12-24 hours. As the jars cool, you should hear a “popping” sound as the lids seal.
After the cooling period, check the seals by pressing down on the center of each lid. If the lid does not flex up and down, it is properly sealed. If a lid does flex, it is not sealed and should be refrigerated and used promptly, or reprocessed with a new lid.
Remove the rings from the sealed jars. This prevents moisture from accumulating between the ring and the lid, which can lead to rust. Wash and dry the jars and rings before storing.
Label the jars with the date and contents.

Expert Tips & Tricks

Consistency is Key: To test if the jam is ready, place a small spoonful on a chilled plate. Let it cool for a minute, then push it with your finger. If the surface wrinkles, the jam is set. If it’s still runny, continue to cook and test again.
Dealing with Foam: Skimming the foam is important for a clear jam, but don’t stress about getting every last bit. A little foam won’t affect the flavor or safety of the jam.
Preventing Sugar Crystals: Adding the lemon juice helps prevent sugar crystals from forming in the jam.
Adjusting Sweetness: Feel free to adjust the amount of sugar to your taste, but remember that sugar is crucial for preserving the jam, so don’t reduce it too drastically. Using slightly under-ripe plums also helps balance the sweetness.
Jar Preparation: Make sure your jars are clean and free from any cracks or chips before sterilizing them.

Serving & Storage Suggestions

Plum jam is incredibly versatile. Spread it on toast, scones, or biscuits for a delightful breakfast or afternoon treat. Use it as a filling for thumbprint cookies or a glaze for grilled meats. Serve it alongside a cheese platter for a sweet and savory combination.

Properly sealed jars of plum jam can be stored in a cool, dark place for up to one year. Once opened, refrigerate the jam and use it within a few weeks.

Nutritional Information

(Estimated, per tablespoon)

Nutrient	Amount per Serving	% Daily Value
Calories	50 kcal	3%
Total Fat	0g	0%
Saturated Fat	0g	0%
Cholesterol	0mg	0%
Sodium	0mg	0%
Total Carbohydrate	13g	4%
Dietary Fiber	0g	0%
Sugars	12g
Protein	0g	0%

Variations & Substitutions

Spice it Up: Experiment with different spices like cardamom, ginger, or star anise for a unique flavor profile. A pinch of ground cloves can also add warmth.
Add Almonds: Stir in some toasted slivered almonds after cooking for added texture and flavor.
Low-Sugar Version: While reducing sugar significantly is not recommended for long-term preservation, you can try using a sugar substitute designed for jam-making. Be sure to follow the manufacturer’s instructions carefully.
Mixed Fruit Jam: Combine plums with other fruits like peaches, blueberries, or raspberries for a mixed fruit jam. Adjust the cooking time as needed.

FAQs (Frequently Asked Questions)

Q: Why is it important to sterilize the canning jars?
A: Sterilizing the jars eliminates any bacteria or microorganisms that could spoil the jam during storage.

Q: How do I know if my jam has set properly?
A: Use the chilled plate test described in the “Expert Tips & Tricks” section. The jam should wrinkle when pushed with your finger.

Q: Can I reuse canning jars?
A: Yes, you can reuse canning jars as long as they are free from cracks or chips. However, you must always use new lids for each batch.

Q: What happens if my jars don’t seal?
A: If a jar doesn’t seal, store it in the refrigerator and use the jam within a few weeks. You can also reprocess it with a new lid within 24 hours.

Q: Why do I need to leave headspace in the jars?
A: Headspace allows for expansion during processing and cooling, creating a vacuum seal that prevents spoilage.

Final Thoughts

Making plum jam is more than just preserving fruit; it’s about capturing the essence of summer and creating something special to enjoy throughout the year. Don’t be intimidated by the canning process – it’s easier than you might think, and the reward of homemade jam is well worth the effort. So gather your plums, follow this recipe, and create your own taste of summer sunshine to share with family and friends. I encourage you to experiment with variations and find your own signature twist. I hope this recipe becomes a cherished tradition for you, just as it is for me.

Plum Jam W/Canning Directions Recipe