Sweet-Tart Plum Jam


I have been a fruit preserving fool lately – I have sixteen jars of homemade jams and butters on my basement shelves. Count them: sixteen! I am gloating just a bit over my bounty, but making jam brings out the squirrel burying nuts for the winter in me. In the past few weeks have made two batches of peach butter, three batches of plum jam and a batch of peach sorbet. I am standing by the sorbet as a method of preserving the fruit, even though it didn’t go into a jar. It will certainly keep longer in the freezer than the peaches were going to keep on the counter or the fridge.

Sadly, the peach sorbet isn’t all it should be, so I will have to do more experiments with that during next summer’s peach season before I will have a recipe for it. But the plum jam is a keeper. Ruby red, tart and sweet, thick and syrupy – everything I want in a jam.


I love how I can take purplish black plums that have yellow flesh and cook them to make beautiful red jam. And I love how the skins of the plums provide all the pectin I need to get the jam to jell. And I love how the plums were sweet enough that they only needed a touch of sugar to be sweet enough for me. Can you tell I love my plum jam?

If you have never cooked plums before, you will be amazed at the transformation they undergo upon cooking. They go from little cubes of juicy fruit to a bubbling mass of thick, syrupy lusciousness in just over an hour. The fresh juiciness of the fruit concentrates and intensifies when you cook them, making a jam that is plum to the nth degree.


I cut my plums into very small dice, because I wanted the finished product to have only a little texture. I didn’t want pieces of plums in the jam. If you like larger pieces and more texture, you can leave your chunks of plum bigger. Be sure to cook the jam long enough, unless you would prefer more of a syrupy sauce. I had to cook mine for over an hour, but it was mostly unattended cooking. I set the timer for 15-minute intervals to stir the jam. The rest of the time I was doing other things in the kitchen.

Get cooking before plums disappear from the grocery store. Already the local produce section is moving from tomatoes and corn to pumpkins and apples. Grab your plums while you can.

Download or print the recipe here.

Plum Jam
From The Cook’s Life
Makes about 1 pint jam

5-6 large plums, red, purple or black preferred (about 2 pounds)
½-¾ cup sugar, approximately
¼ cup lime or lemon juice (juice of 1 lime or 1 small lemon)

Wash the plums really well. Cut plums in half and remove the pits. Don’t peel the plums. Dice plums into small cubes.


Combine plums, ½ cup sugar and juice in a 3-quart pot. Cover and bring to a boil over medium high heat. The plums will produce juice – this is what you want. Once plums boil, reduce heat to medium and uncover the pot. Stir the plums and make sure they aren’t sticking to the bottom of the pot.


Cook the plums over medium to medium low heat until they are reduced by almost half – 45-90 minutes.  The cubes will cook down into a syrupy, thick mass. The mixture will turn a beautiful ruby red or purple from the skins. You may have to lower the heat as the plums cook down, but try to maintain a slow, bubbling boil.

Once the jam is reduced somewhat, taste it for sweetness – after waiting for a spoonful to cool. Really. It is hotter than you think. If it is too tart for your tastes, add up to a ¼ cup more sugar. Stir to dissolve. Taste again for sweetness and adjust if necessary.


When the jam is done, it will fall off a spoon in a sheet instead of individual drops. You can also spoon a teaspoon of jam onto a clean plate, let it cool for several minutes, and then draw your finger through it. Your finger should leave a trail that only slowly closes up, if at all. But relax. It is jam. The worst thing that can happen if you don’t cook it long enough is you will get thinner plum jam.

When the plums are cooked, transfer the hot jam to hot jars if canning the mixture. Process the jars in a boiling water bath for 20 minutes. See my tutorial on canning for complete directions on canning jam.

If you aren’t canning the jam, store it in the fridge for up to two weeks. Freeze it for longer storage.

Back to Basics – Home Canning


I avoided any sort of canning for years. I had a picture in my head of vats of boiling water and steam clouded windows, rows and rows of jars, bushels of fruit and me, toiling over the hot stove with sweat streaming down my brow. Canning doesn’t have to be like this. It certainly isn’t when I do it. I finally ventured into canning several years ago and wondered why I had waited so long.

The first time I made blackberry jam and canned it was a revelation. I had seedless, slightly tart blackberry jam that I was unlike anything I could buy in the stores, and I could eat it in January. The canning process wasn’t hard, once I understood what I was doing. Since then I mostly have canned fruit based products that are exactly what I want – peach butter that is preserved summer sunshine in a jar, sweet-tart plum jam, spiced pear preserves and the blackberry jam, when my parents’ blackberry vines have a good year.


Canning is not hard. And you don’t have to can huge amounts of vegetables or fruit at a time. And it isn’t a mysterious process. It basically boils down (see the pun here?) to cooking your filled canning jars in boiling water until they are germ free and vacuum-sealed.

I usually can a few jars of jam or preserves at a time. I can make the jam and can it in an afternoon. I can even make the jam one day and can it another day, as long as I heat up the jam again before filling the hot jars (so they don’t break from the difference in temperatures).


A Note on Sources
You can find umpteen sites online that give you directions and recipes for canning. Make sure you are reading reputable sites with up-to-date information. There are a lot of unsafe and outdated canning methods out there. The National Center for Home Food Preservation, university extension services and the Ball canning site all have information you can trust. I use all of them for reference.

To Buy a Canning Kettle or Not
You need a canning kettle or other large pot that is deep enough to hold your jars and water to cover the tops of them by at least an inch. If you are using something other than a canning kettle, which comes with a rack insert, you need a rack or trivet in the bottom of the pot to elevate the jars a bit. I don’t have a canning kettle – I use my giant pasta pot with a rack in the bottom. There are kits that have a rack or jar caddy, and other canning tools. They are nice, but you can get by perfectly well with a big pot, a rack, a pair of tongs and a ladle.

I recommend canning in pint, half-pint or even smaller jars. I like the smaller jars for gift giving and so that we can finish each jar relatively quickly. If you decide to can in quart jars, you probably will want a canning kettle, since it will be tall enough to get the water deep enough. You might not want to invest in a canning kettle if you aren’t going to be canning a lot, or if you aren’t going to be canning quart jars.

Most sources say you don’t need to sterilize jars for foods that are going to be processed in a hot water bath for more than ten minutes. I tend to err on the side of caution and sterilize mine anyway. Even if you don’t sterilize your jars, you need to heat them up in hot water so you aren’t adding hot food to room temperature jars, which could lead to broken jars. I have never (so far) canned a batch of jam or preserves that has molded, so I think I will stick with my method. I would rather play it on the safe side than have to throw away a batch of moldy preserves.


A Note on Jars and Lids
Be sure to use jars and lids made for canning. Don’t reuse jars from commercial products. You can reuse glass canning jars and the threaded lid bands, but you can’t reuse the flat lids. Once they have been used once, the rubber seals won’t form a proper seal again. You can buy packages of just the flat lids if you are reusing jars and bands.

The Actual Canning Process
Wash your jars, flat lids and bands in hot soapy water.

If you aren’t sterilizing your jars, keep them hot until you are ready to use them. If you are sterilizing your jars, put them in the kettle or pot and fill it with water to cover the jars. Bring it to a boil over high heat, covered. Boil the jars in the water for 15 minutes to sterilize them. Boil the flat lids and threaded rings in a smaller pot, also covered, for the same amount of time. Throw the ladle that you are going to use to fill the jars into one of the pots.

When your jars are sterilized, leave them in the hot water until right before you are ready to use them. Lift them out of the water with tongs and drain the water out. The jars will be hot – use an oven mitt to handle the jars. Don’t dump out the hot water in the kettle – you will use it again for the actual canning process.


Fill the jars with hot jam or preserves, leaving the headspace specified in the recipe you are using. Wipe the tops of the jars clean. Fish the flat lids and rings out of the hot water with tongs and put them on the jars. Tighten them only finger tight and put the jars back in the canning kettle or your large pot with a rack. If you over-tighten the bands air will not be able to escape and the vacuum seal might not form properly. Add hot water if necessary to cover the jars and reach an inch above their tops.

Bring the water back to a boil and keep it boiling for the time specified in the recipe you are using.

Remove the hot jars with tongs and place them on a folded towel or wooden cutting board. Let them rest, undisturbed, until they are room temperature. This will take several hours. You will hear the lids pop as the vacuum seal forms. If any of the jars don’t form a seal, which will vacuum the lid down, refrigerate and use them within a couple of weeks.


When the jars are cool, label them and store them somewhere cool and dark. Give as gifts or open them one at a time over the months, gloating every time over your home canned, homemade jam.

Taste of Spring Jam

I made jam again today. I know I did a post on jam a few weeks ago, but I couldn’t resist the strawberries and rhubarb at the local produce farm. I have been wanting to do something with rhubarb for a while, but I wasn’t sure I really even liked it. So I combined it with strawberries and made jam. Why mess with a classic combination?

I decided to can the jam since I am still eating the peach and strawberry preserves I made a few weeks back. I didn’t want to take up freezer space with the jam, so the only choice was canning. And then I would also have the option of using the jam for Christmas presents. Canning is relatively easy, even if you have never done it before. It really is a matter of boiling your filled jars in a water bath for the recommended time. Now this holds true for jams, jellies and pickles. Some things can’t be canned safely without a pressure canner, which I don’t have. If you are exploring canning, check a reliable source, like your local university extension or the Ball canning website to make sure you are using reliable and up-to-date directions. You don’t want to make anyone sick with your kitchen efforts.

I diced up my rhubarb and sliced the strawberries and mixed them with sugar. I think I might have used too much sugar, but I was afraid the rhubarb would be too sour without it. I must say I wasn’t too fond of the smell of the rhubarb cooking, but once the strawberries got going, everything smelled like roses strawberries. My jam wasn’t getting thick, and I forgot to get any pectin at the store (not that I have any experience with pectin, but I know what it is supposed to do). I know apples have pectin, especially in the peels, and I already had two kinds of fruit in my jam, so I chopped an apple in my mini food processor and added it to the mix. Another 15 minutes’ cooking and I was happy with my jam. It was sweet and tart and thick enough to spread on toast, though not as thick as commercial jam.

I washed and sterilized the jars while the jam was cooking and then filled the hot jars with the hot jam. I used my stockpot to process them, since I don’t have a canner (and forgot to borrow my mom’s last time I saw my parents). This was easier since I was using short, half-pint jars, which didn’t require the depth of the canner to make sure they were covered in water. Ten minutes to come to a boil, ten minutes boiling and my jam is now (hopefully) germ-free and vacuum-sealed to be shelf safe. Now it just needs to cool its heels in the basement and wait to be a taste of spring in the winter. I also made a few jars of plain strawberry jam to enjoy right now, as soon as fresh strawberry season is over. I canned those too, but I don’t think they will make it to winter!

Strawberry Rhubarb Jam
from The Cook’s Life
5-6 ½-pint jars

3 large stalks rhubarb, diced (about 3 cups of ½-inch pieces)
2 pints strawberries, sliced (about 6 cups)
½-1 cup sugar, to taste
1 apple, UNPEELED, cored and chopped fine in a food processor

Combine rhubarb, strawberries and ½ cup sugar in a 3-quart, or larger, saucepan. Bring to a boil over medium heat and cook uncovered for 30 minutes. Add the chopped apple and continue cooking for another 15 minutes, or until desired thickness.Taste for sweetness and add up to ½ cup more sugar, if desired. Jam will taste less sweet when cool.

If eating within a week or two, you don’t need to can the jam. Ladle the hot jam into clean canning jars and close the lids. Let the jars cool on the counter until they are room temperature. The lids may pop, which signals a vacuum seal has formed, but they aren’t shelf stable unless you process them in a boiling water bath. Store in the refrigerator once the jars are cool. Or store in the freezer for longer storage.

*To can your jam:

Wash your canning jars, lids and rings. Sterilize the jars by boiling them in water for 10 minutes. Use your canner or stockpot to sterilize the jars and then you can use the same water for the processing water bath later. Leave the jars in the hot water until you are ready to fill them. Boil the flat lids for 10 minutes and leave them in the hot water until you are ready to use them.

Ladle the hot jam into the hot jars and wipe the edges clean of any spilled jam. Put the lids on top, and screw the rings onto the jars, but only finger tight. Place the jars in a canner or a stockpot and fill it with water until the jars are submerged by at least an inch.

Cover the pot and bring to a boil. Keep the water at a steady boil for 10 minutes. Keep the lid on so your water doesn’t evaporate below the tops of the jars. Carefully remove hot jars and place on a towel to cool, undisturbed. Once the jars are cool, the lids should not move up and down when you press on them, indicating the vacuum has been formed. If any jars have not formed a seal, store them in the fridge and eat them within a week or two, just like unprocessed jam. Your canned jam should last about a year, stored in a cool dark place. Refrigerate the jam after opening.

*Check out the Ball canning website for all the details on home canning.

Download the recipe here.