There’s nothing better than turning homegrown fruit into jam, and this year my backyard Damson plum tree gave me a beautiful harvest. With the help of Certo pectin powder, I made a batch of Plum Jam that set perfectly and captured the deep, rich flavor of fresh tart plums. If you’ve been wondering how to make Plum Jam with Certo, here’s a step-by-step guide.
It seems like just the other day that I made my plum jam and plum sauce—but it was actually in mid-September. My little plum tree suddenly overflowed with ripe blue and purple plums! They were dropping faster than I could gather them, covering the ground beneath the branches.
Don’t worry – there’s a printable recipe card at the bottom of this post!
I’ve been making preserves for it seems like forever. My mother always made Strawberry Jam and Pickled Beets and many other things. I’ve carried on from her traditions – and added a few more!
My Plum Tree History
For many years we lived in a rural area in Southern Ontario. When we first bought the property, there were no trees, and the wind swept freely through the yard and fields. One of my first plantings was a yellow plum tree, which I tended with great care.
When the tree finally produced fruit, the plums disappeared suddenly—all at once. At the time, not realizing how quickly birds can swoop in, I thought my precious plums had been stolen. Later I learned that a flock of birds can feast and completely strip a tree of fruit in a single visit!
As we settled in and grew our family, we planted a small orchard of assorted pear, apple and asian pear trees. They were easy to grow and I enjoyed making all manner of pear and apple treats and preserves – and even Hard Apple Cider and Perry (pear cider)! As these little trees matured, they produced an excess of 2500 pears and apples per year.
We would get excited and harvest the fruit all at once and then have to process it before the fruit flies took over the house.
Nearer to the garage, we planted a Damson plum tree, which yielded so many delicious plums (from which I made Plum Jam, Plum Sauce and Cordial) for many years – until a fire burnt the garage and the plum tree to the ground. I’m not sure which I missed the most……
A few years ago we retired and moved to our little village. During the pandemic, I missed my fruit trees so much that I planted another Damson plum (In my perennial food garden -with raspberries, asparagus, rhubarb, herbs and even a Pawpaw tree!) Four years after planting, this small tree has yielded so many beautiful dark blue and purple fruit, that I can’t help making more Plum Jam!
Why Use Damson Plums for Jam?
Damson plums are small, tart, and perfect for jam-making. Their natural tang balances beautifully with sugar, and because you don’t need to peel them, they’re easy to prepare. The skins give the jam a gorgeous ruby-purple color and an extra depth of flavour. My husband loves to enhance his barbecue sauce with it. I just put it liberally on toast!
Why Keep the Skin On?
It’s Easy– That’s the most obvious reason. You just wash the plum, pop out the pit, stem and anything unpleasant – and you are ready to go. Damson plums are fairly small and who wants to spend time peeling the little things?
Pectin content – Plum skins, especially those of tart or slightly under-ripe plums, contain natural pectin. Pectin is the substance that helps jams and jellies gel. So when you cook the fruit with the skins on, you’re adding more pectin to the mix. My jam recipe uses pectin – but I don’t peel the fruit, because the recipe assumes the skin is retained.
Tannins and texture – The skins also contribute tannins, which can help the jam thicken and give it body.
Colour and flavor – While not directly related to setting, the skins add rich colour and a deeper plum flavor.
Sterilizing Jars for Canning
For safe storage, you’ll need to sterilize your jars and lids before you start making jam!
- Wash jars and lids in hot, soapy water.
- Boil jars in water for 10 minutes to sterilize.
- Simmer lids in hot (not boiling) water to soften the sealing compound. Bernardin now states that it’s better not to boil the lids – as the adhesive works without boiling – but I question how the lids will be sterilized if they are not boiled?
This recipe calls for 7 250 ml jars – but I always prepare 2 or 3 extra!!
Preparing the Plums
Making Plum Jam starts with a little prep work:
- Wash the plums thoroughly.
- Pit the plums by slicing them in half and popping the pits out. No peeling required!
- Lightly blend or crush the fruit. I like to puree the plums gently in my blender so the jam has a smooth-but-textured consistency. You can also crush them with a potato masher if you prefer chunkier jam.
The traditional Certo Plum Jam recipe doesn’t call for blending the fruit – but I prefer the texture when lightly blended, so that you don’t get a big piece of plum skin in your jam on toast!
Plum Jam Recipe with Certo Pectin Powder
This recipe follows the classic Certo Plum Jam method, which provides the perfect balance of fruit, sugar, and pectin for a reliable set. I’ve kept the original proportions but added a few of my own tips along the way to make the process smoother.
Plum Jam with Certo Pectin Powder
Yield: ~7 cups ++
Ingredients
- 4 cups prepared damson plums (washed, pitted, not peeled, any yucky bits removed and lightly pureed) – I started with a little more than 3 pounds of freshly picked plums
- 1 box Certo pectin powder (57 grams or 2 ounces)
- 5 cups granulated sugar
- ¾ cup water
Instructions
- Wash and sterilize jars and lids. Use clean fresh mason jars, and then boil them for about 10 minutes and drain them on a clean surface – I used about 7 250 ml jars. I always prepare a few extra jars for when I have extra jam!
- Prepare plums by halving, pitting, and lightly pureeing. Use only fresh mold free fruit! Boiling moldy fruit doesn’t kill mold – so please just don’t use moldy fruit!
- Combine fruit and water in a large pot, bring to a boil.
- Stir in Certo pectin, return to boil. The key is to whisk in the pectin to make sure that it dissolves evenly and quickly and doesn’t stick to the sides of the pot.
- Add sugar all at once, stirring constantly. Keep whisking to assure that the jam doesn’t congeal on the sides or bottom of the pot.
- Boil hard for 1 minute.
- Ladle hot jam into sterilized jars, leaving ¼ inch headspace.
- Wipe rims, apply lids, and process in a boiling water bath for 10 minutes.
How to Can Plum Jam
Once the jam is cooked:
- Ladle hot jam into hot jars, leaving about ¼ inch of headspace. I use silicone oven mitts to help me and keep me from getting burned!
- Wipe rims clean to ensure a proper seal. I keep fresh paper towels on hand – this can get messy!
- Apply lids and screw bands on firmly but not overly tight.
- Process jars in a boiling water bath for the time recommended in the Certo instructions. I use those same silicone mitts again! At altitudes up to 1000 feet – this is 10 full minutes.
This final step is essential for food safety and gives your jam a shelf-stable seal.
Enjoying Homemade Plum Jam
When cooled, your jars should have a firm seal and the jam will set beautifully. The Certo and the pectin from the fruit skins work together to firm up the jam! The properly sealed jars should pop gently as they cool and the lid should become converse.
Plum Jam is versatile—you can spread it on toast, stir it into yogurt, use it as a filling for cakes and cookies, or even glaze roasted meats. This Jam is richly coloured and is quite tart – sometimes people think it’s a tart strawberry jam – but it’s not!
Plum Jam with Certo Pectin: FAQs
Do I need to peel plums for jam?
No, plum skins add flavor, texture, and color to the jam, so you can leave them on.
Can I use Certo liquid pectin instead of powder?
Yes, but the recipe instructions are slightly different. Always follow the directions on the Certo package you’re using. This recipe is just for Certo pectin powder.
How long does homemade Plum Jam last?
Properly canned jam stored in a cool, dark place can last up to a year. Once opened, refrigerate and use within a few weeks.
Can I make this recipe without Certo?
You can, but plums vary in natural pectin content. Using Certo powder ensures your jam sets reliably.
Can I freeze the processed fruit and make the jam later?
Yes. Damson plums can be washed, pitted, and flash frozen if you’re not ready to make jam right away. Spread the prepared fruit on a baking sheet to freeze individually, then transfer it to a freezer-safe bag or container. When you’re ready, just thaw the plums and continue with your jam recipe as usual. The flavor and texture hold up beautifully, so your finished jam will be just as delicious.
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You’re so right, home-made jam is best.
I loved reading your post. We grow cherries apples and plums in our area. I have recently moved here and definitely want my own plum and apple tree. My mother used to make plum jam as well… Absolutely delicious.
Impressive! Looks so delicious.
Yes, to the perfect toast-topper . . . next -level delicious!
What a delightful ode to the humble Damson plum! Who knew a small, tart fruit could cause such joy and such a desperate craving during lockdown? I completely relate to the panic to plant another tree before the flies win! The article is wonderfully informative, from the easy peasy pit-popping to the serious business of jar sterilization (boiling lids, really?Bernardin, have you considered the logistics of *not* boiling?!). While my jam-making skills are likely nowhere near the authors perfection, their love for the fruit shines through. And yes, that purple hue is undeniably gorgeous on toast! A truly plum-tastic read for any jam enthusiast.