My sister has a plum tree that gives so many plums, we can't eat them fast enough, so I've taken to canning to preserve some of these plums for when the summer is long over.
The first year I started I canning, I constantly worried about poisoning everyone. But after practicing, I'm a bit more comfortable and have started to really enjoy jam making because I can make flavor combinations I can't find in a store. Plus I always make low sugar jams to be healthier.
I found this cool website, NWedible.com, that has a detailed flavor maker chart of possible spice pairings with various fruits (dry Zings and wet Zings as Erica calls them) for jam making. I have tried a few of them for apricots and plums. It's really fun to experiment! My absolute favorite thus far is a variation of this Chocolate Plum Jam from cupcakerehab.com! Other variations of chocolate plum jams on the internet, such as Jo's Plum and Chocolate spread recipe at Jo's Kitchen Larder.com or Sissi's Plum, Prune and Chocolate Jam recipe seem to indicate that plums paired with chocolate is common in Poland. Very interesting, and definitely a place I want to visit once a vaccine is out for COVID-19!
Anyways, jam making is very easy. You basically cook the cut fruit with sugar and spices of your choice until the jam is the consistency you like. Add lemon juice or acid for safety purposes if you plan to store the jam at room temperature. Ladle hot jam into sterilized hot jars, and water bath can according to standard procedures.
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| Macerate cut fruit with sugar overnight in fridge |
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| When volume has reduced by half, add lemon juice. |
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| Ladle hot into sterilized hot jars, and try not to make a mess! |
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| Water bath can according to proper reliable canning procedures |
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| Enjoy your jam! |
Below are a few plum jam recipes that I've made and liked. Since it's the start of summer, I figured these recipes might be useful for some of you out there with trees brimming with plums as well.
I've also put together a few reference notes on canning jams for myself (and you) here:
- For boiling water bath canning safety, the overall jam needs to be below pH 4.6 so that the resting C. botulinum spores don’t get activated and reproduce, generating botulinum toxin. Most fruits are acidic enough (great pH reference chart here), but out of precaution, I always add some lemon juice (pH 2.0-2.6) or lime juice (pH 2.0-2.35) for jams; or cider vinegars (pH 2.8) for savory plum sauces. For border-line fruits or fruits above pH 4.6, use 1 tablespoon lemon juice or 1/4 teaspoon citric acid for every pint of product.
- Sugar acts as a preservative, and helps to “set” the jam, so you can’t go too low on the sugar. Low sugar jams last only 1 year on the shelf. Once opened, keep in fridge and eat within 3 weeks. Lowest you can go for canning is 1 c plus 2 T sugar to 6 c chopped fruit (about 3 lbs fruit) that is reduced down to 4 to 5 half-pints of jam. That's still only a quarter of the amount of sugar in normal jams.
- Chopping the fruit and letting it sit in the fridge overnight with the granulated sugar helps macerate the fruit and cuts down on the cooking time and thus helps to preserve the fresh fruit flavor. I learned that from Kenji Lopez-Alt on Seriouseats.com
- Bubbles in the finished product are OK if you processed the jars according to appropriate recipe time. Sometimes that happens when the jam is too thick. (More on bubbles in finished product via canning expert Marisa at “Food in a Jar”. Phew! I knew I freaked out the first time that happened to me! )
Of course, always follow the guidelines regarding safe water canning techniques from the National Center for Home Food preservation.
UPDATE ADDED July 2, 2020: I've made these jams in the past and given them to family and friends and of course eaten them myself, and nobody's died of food poisoning, so I'm confident the recipes are safe for water bath canning. However, ever since I've posted the recipes on this blog last week to the public, I started getting worried and wanted to be 100% sure the pH of the recipes were below 4.6 for safe water bath canning. So I got a hold of some pH paper and tested all the jams and sauces here that had added spices/ingredients. All were well below pH 4.6, so I guess I was all worried for nothing. (See photos below corresponding to each Jam's pH of around 3.5)
BASIC LOW SUGAR PLUM JAM
Yields a nice plum flavored jam that is tart, but terrific on bread, toasted muffins, or stirred into plain yogurt or oatmeal
Ingredients:
- 6 c chopped plums*, pits removed, skin stays on (about 3 lbs)
- half a lemon, juiced (about 2 T)
- 2 c sugar
* pH 2.8 to 4.3 for plums, so lemon juice is more for flavor rather than safety
Procedures:
1. Combine chopped plums with the sugar in a bowl and let it macerate overnight or at least 1 hour in the fridge.
2. The next day, simmer mixture in a stainless steel pot under medium high heat for 35 minutes with stirring. You want the volume to decrease by about 40%.
3. Add the lemon juice, and cook for another 10 minutes. Taste with a CLEAN spoon and adjust sugar to your taste. I like my jams more tart, but everyone’s preference is different, so adjust to your taste. (Total cooking time is about 45 minutes.)
4. Ladle jam into 4 sterilized hot half-pint jars (maybe 5 jars, so have another one ready just in case, but I had enough for just 4 jars), leaving ½ inch head space. Clean rim of jars with a damp paper towel, place lid, screw on band to finger tightness.
5. Process in a boiling water bath for 15 minutes. Turn off heat. Let jars sit 5 min, then remove from water bath to cool at room temperature for 12 hrs. Check seal. If seal is not tight, put in fridge and eat within 3 weeks. If seal is tight, store in a cool dark place for up to a year.
SPICED PLUM JAM (LOW SUGAR)
Yields a nice warm spiced plum flavored jam that reminds me of Christmas. It’s terrific on crackers, bread, toasted muffins, or stirred into plain yogurt or oatmeal, or as a topping for vanilla ice cream. Heck, I think it would work well as a substitute for the Thanksgiving cranberry sauce, but I've learned to not mess with tradition, or else receive the evil eye on Thanksgiving day.
Ingredients:
- 6 c chopped plums*, pits removed, skin stays on (about 3 lbs)
- half a lemon, juiced (about 2 T)
- 2 c sugar
- 1 t cinnamon
- ½ t nutmeg
- 6 cloves
* pH 2.8 to 4.3 for plums, but the added spices may affect the pH level, so add lemon juice just in case
Procedures:
Same procedures as the recipe for Basic Low Sugar Plum Jam above, except add in the cinnamon, nutmeg and cloves with the sugar and plums in step #2 of simmering. Then, fish out the 6 cloves before canning. It may be difficult, but do the best you can. This recipe fills 4 to 5 half-pint mason jars.
CHOCOLATE PLUM JAM (LOW SUGAR)
Adapted from Marilla's recipe at cupcakerehab.com Yields a nice chocolaty flavored plum jam that is now my favorite jam to make with plums. It's like Nutella, but has a tart fruity flavor as well. It’s terrific on bread, pancakes, inside a croissant, as a topping for vanilla ice cream, or just licked straight off the spoon!
Ingredients:
- 4 c chopped plums*, pits removed, skin stays on (about 2 lbs)
- 4 T unsweetened natural cocoa powder, not Dutch-processed^
- 1 ½ c sugar
- 1 ½ T lemon juice
* pH 2.8 to 4.3 for plums
^ pH 5.3 to 5.8 for natural cocoa powder, and pH 7-8 for Dutched-processed cocoa or European style cocoa powder. So first, use the natural cocoa powder, NOT the more alkaline Dutch-processed cocoa powder. And second, don’t add more cocoa powder just because you like chocolate. Too much will render the jam unsafe for water bath canning. Finally, make sure you add lemon juice in this recipe to lower the pH. Dang, sometimes I wish I was still in lab with access to a pH meter.
Procedures:
Same procedures as the recipe for Basic Low Sugar Plum Jam above, except add in the cocoa powder with the sugar and plums in step #2 of simmering. This recipe fills 3 half-pint mason jars.
SAVORY ASIAN PLUM JAM
Recipe adapted from thedaringgourmet.com
Yields a salty, sweet, sour jam with a hint of Chinese 5 spice, that is perfect as a condiment for dumplings, egg rolls, pork chops, baked chicken, or roasted duck.
Ingredients:
- 6 c chopped plums*, pits removed, skin stays on (about 3 lbs)
- 3/4 c packed brown sugar
- 3/4 c sugar
- ¼ c soy sauce
- 1 t garlic powder
- 1 t powdered ginger
- 1 T dried chopped onions
- 2 t Chinese five spice powder
- ½ t salt (or 1 t salt if you like yours saltier)
- 3/4 c apple cider vinegar
* pH 2.8 to 4.3 for plums, but the added dry spices may affect the pH level, so don't skimp on the amount of apple cider vinegar even if you think the sauce may be too sour. Add more sugar if you think it is too sour.
Procedures:
1. Place all ingredients in a stainless steel pot, and cook under medium high heat for about 40 minutes with stirring. You want the volume to decrease by about 20-30%.
2. Taste with a CLEAN spoon and adjust sugar to your taste. I like my jams more tart, but everyone’s preference is different, so adjust to your taste. (Total cooking time is about 40 minutes.)
3. Ladle jam into 5 sterilized hot half-pint jars (maybe 6 jars, so have another one ready just in case, but I had enough for just 5 and a half jars), leaving ½ inch head space. Clean rim of jars, place lid, screw on band to finger tightness.
4. Process in a boiling water bath for 20 minutes, turn off heat, sit 5 min, then remove from water bath to cool at room temperature 12 hrs. Check seal.