Updated July 23, 2026: I added a “Why This Works” section explaining the science behind why the canning version needs more sugar and bottled lemon juice than Omi’s original — and a Troubleshooting section for the most common things that go sideways (runny jam, scorching, jars that don’t seal). The recipes themselves haven’t changed a bit — still exactly the way Omi wrote them, and the same tested canning adaptation. Just more help if something doesn’t go perfectly the first time.
If your kitchen counters are buried under plums (along with everything else the garden insists on ripening at once), you’re in good company. I love it when my plum tree is loaded with fresh fruit, but every fall the harvest sneaks up on me, and suddenly I’m racing the fruit flies.
That’s when I pull out my favorite plum jam recipe — the one that’s saved me more than once — and often make a few other fall standbys like my Apple Pie Jam and Old-Fashioned Pickled Beets.
This plum jam recipe is extra special because it comes straight from my German Omi, Gerda. She made her jam the old-world way — just plums, a little sugar, and lemon juice. No pectin, no fuss, no canning. Just a big pot of fruit simmering on the stove until thick, then tucked into the fridge.
Here she is, my Omi Gerda, standing in her garden where so many of our family traditions began.
I first discovered this piece of family history thanks to my sister Annette, our unofficial family historian. One Christmas, she gave us a homemade family cookbook filled with everyone’s favorite recipes, plus a few treasures that had been passed down. Tucked inside was Omi’s plum jam, written in her own handwriting on a scrap of paper.
One thing you’ll notice: European recipes often use far less sugar than American canning standards consider safe for water bath processing. That’s why Omi’s recipe works beautifully as a freezer jam, but it needs some adaptation if you want it to be shelf-stable.
So today, I’m sharing both recipes for homemade jams:
- Omi’s German freezer plum jam – low sugar, pure fruit flavor, straight from her kitchen
- A safe water bath canning version – adapted for pantry storage and holiday gifting
That way, you can enjoy the nostalgic jam I grew up with and the USDA-approved version for stocking your shelves this fall.
If you want to understand how all of this fits together — from water bath canning to freezing, pickling, and more — start here: Home Canning & Preserving: The Complete Beginner’s Guide.
Why You’ll Love This Plum Jam
- ✅ Two recipes in one post – freezer jam or canned, your choice
- 🍇 Simple ingredients – just ripe plums, sugar, and lemon juice
- 🎁 Great for gifting – jewel-toned jam jars dress up holiday baskets
- ⏱️ Quick to make – both versions take less than an hour of cooking
- 🌟 Family tradition – this recipe comes from my German grandmother, Omi
Omi’s German Freezer Plum Jam
This is the way my Omi made it every year — simple, low sugar, and full of deep plum flavor. Because it uses fresh lemon juice and less sugar, it’s not safe for pantry storage, but it’s perfect for the fridge or freezer.
This German plum jam recipe comes directly from Omi’s handwritten notes.
Ingredients
This recipe will make 6 to 7 half-pint jars.
- 5 1/2 pounds plums (about 11–12 cups, chopped, pits removed, skins on)
- 2 1/2 cups sugar (or as little as 1 1/4 cups for a more tart, traditional flavor)
- Juice of 1 fresh lemon (or vinegar — Omi’s WWII substitute)
Instructions
Wash, pit, and chop the plums.
Place the plums in a large bowl, add sugar, and stir to combine. Cover and let the mixture macerate overnight. (This draws out the juices and deepens the flavor.)
The next day, transfer the plums and their juices into a heavy-bottomed pot. Add the lemon juice.
Bring the mixture to a full boil over high heat, then reduce the heat to low and simmer gently for approximately 3 hours, stirring occasionally, until the jam has thickened and become glossy.
Note: Yes, it really does take about 3 hours — Omi’s slow simmer method concentrates the flavor into something special.
As Omi wrote at the bottom of her recipe: “Dann fertig” — then it’s finished. 💛
Ladle the plum mixture into clean jars, let cool, and refrigerate for up to 3 weeks or freeze for up to 6 months (leave 1/2 inch headspace if freezing).
👉 Expect this easy jam recipe to produce a soft, loose set — more like a fruit spread than a firm jam.
Notes: These are the exact ingredients from Omi’s handwritten recipe. During and after WWII in Germany, lemons weren’t always available, so she sometimes used vinegar instead. I recommend lemon juice if you can find it. And since American palates tend to prefer a sweeter jam, I suggest using about 2 1/2 cups sugar — still less than half of what most U.S. jam recipes call for.
This traditional German plum jam recipe is simple, low-sugar, and still one of my favorite ways to preserve plums in the fall.
If you love lower-sugar preserves, you’ll also enjoy my Vanilla Cherry Jam, which has the same rich fruit flavor with just a touch of sweetness.
Safe Water Bath Canning Plum Jam
This recipe makes about 7 to 8 half-pint jars, thanks to the higher sugar content.
This safe water bath canning plum jam recipe is an adaptation of Omi’s original. By using bottled lemon juice for standardized acidity and a bit more sugar, you’ll get a shelf-stable jam that can be stored in the pantry for months or dressed up as holiday gifts.
Ingredients
- 5 1/2 pounds plums (about 11–12 cups chopped)
- 4–5 cups sugar (depending on plum sweetness)
- 1/4 cup bottled lemon juice
- Optional: 1 packet low/no sugar pectin (for a firmer set with less sugar)
Step-by-step Instructions
- In a large pot, combine plums and bottled lemon juice.
- Stir in sugar (and pectin, if using).
- Bring to a full rolling boil, stirring constantly, and cook until thickened to your preferred jam consistency (20–25 minutes).
- Ladle hot jam into sterilized jars, remove any air bubbles, leaving 1/4 inch headspace.
- Wipe rims, apply lids and bands.
- Process in a boiling water bath canner for 10 minutes. Remember to adjust the processing time according to your altitude, if necessary.
- Remove the jars from the canning pot with a jar lifter, cool 24 hours on a towel-lined baking sheet, and check seals. Store up to 18 months in a cool, dark place such as a cupboard or pantry.
Why This Works
Here’s the thing about Omi’s recipe — it’s not actually broken, it’s just not built for a pantry shelf.
Sugar and acid are what make jam safe to store outside the fridge. Omi’s version is low on both, which is exactly why it tastes like fruit instead of candy — but it’s also why it can’t sit in a cupboard next to your green beans.
The canning version isn’t a different recipe. It’s the same plums, adjusted two ways so the science works.
More sugar helps the jam set and acts as a preservative — it’s doing a job, not just adding sweetness. And swapping fresh lemon for bottled isn’t me being fussy. Fresh lemons vary in acidity from one fruit to the next, and you’d never know by tasting it. Bottled lemon juice is standardized, so every batch hits the same safe acidity every time. That consistency is what a boiling water bath actually depends on.
Skip either adjustment, and you don’t get “close enough” — you get a jar that isn’t shelf-stable, whether or not it looks fine sitting there.
So: two jams, same plums, same pot. One is built for nostalgia. One is built to sit on a shelf until February. Now you know which is which, and why.
Side-by-Side: Freezer vs. Canning
| Omi’s Freezer Jam | Canning Version | |
|---|---|---|
| Sweetness | Low sugar (soft set) | Medium sugar (firmer set) |
| Lemon | Fresh lemon juice | Bottled lemon juice (tested acidity) |
| Storage | Fridge (3 weeks) or freezer (6 months) | Pantry shelf (12–18 months) |
| Best For | Everyday family snacking | Holiday gifting & long-term storage |
If you want to understand how all of this fits together — and feel confident using the right method every time — start here: Home Canning & Preserving: The Complete Beginner’s Guide.
Troubleshooting
My jam won’t set — it’s still runny after cooling.
Give it the full 24 hours before you panic; jam keeps setting as it cools. Still loose after that? Keep simmering it a little longer to cook off more liquid, or stir in a bit of powdered pectin mixed with sugar and boil for another 1–2 minutes. Omi’s version is supposed to be soft and spreadable — if you made her recipe, that loose set isn’t a mistake, it’s the point.
My canning version didn’t seal.
Don’t force it. A jar that didn’t seal goes straight in the fridge and gets eaten within 3 weeks — no different from the freezer batch. It’s not spoiled, it’s just not shelf-stable. Check that your lids weren’t reused (they’re one-time use) and that you left the right headspace next time.
My jam scorched on the bottom.
This one’s usually a heat problem, not a recipe problem. Omi’s 3-hour simmer needs a heavy-bottomed pot and a low, patient heat — not a rolling boil left unattended. If you catch it early, transfer what didn’t scorch into a clean pot rather than trying to save the whole batch; scorched flavor doesn’t cook back out.
My jam is too thick, almost like fruit leather.
You went past the setting point. It’s still safe to eat, just more spread than jam at this point — great on a cheese board, less great on toast. Next batch, start testing for doneness a few minutes earlier than you think you need to.
Can I fix a batch that’s already jarred and cooled?
For the canning version, yes — dump it back in a pot, add fresh lemon juice, bring it back to a boil, retest, and re-jar in clean sterilized jars. For the freezer version, easier to just call it a thinner spread and use it as-is; it’s not shelf-stable either way, so there’s no safety issue with a soft batch.
Ways to Use Plum Jam
- Spread on toast, biscuits, or scones
- Spoon this delicious jam into yogurt or oatmeal
- Layer into thumbprint cookies or cake fillings
- Glaze for roasted pork or chicken
- Pair with cheese boards (brie, goat, or cream cheese)
- Tuck into homemade holiday gift baskets
- Spoon over ice cream
- Use in your favorite plum drinks
Shop This Post
- Ball Half-Pint Jars (12-pack) — the right size for both versions of this jam
- Jar Lifter — non-negotiable once that canning version comes out of boiling water
- Wide-Mouth Canning Funnel — keeps the ladling mess-free for both recipes. This version is my new favorite!
- Immersion Blender — if you want a smoother jam instead of Omi’s rustic texture, this cordless version is the one I use.
- Ball Complete Book of Home Preserving — my go-to reference if you want to branch into other fruit jams after this one
Final Thoughts
This homemade plum jam recipe is more than just a way to use up a mountain of plums — it’s a taste of tradition. My Omi made hers the old-world way, low on sugar and big on fruit flavor, and I still make that freezer version whenever I want to relive those memories.
But I’ve also learned the value of adapting recipes for today: a safe water bath canning version means I can line my pantry shelves with jars of jam and store them for winter breakfasts, cozy roasts, and even holiday gifts.
So if your counters are covered in plums this fall, don’t let the fruit flies win. Make a batch of jam and, while you’re at it, try stocking your pantry with Homemade Apple Butter or Canning Salsa — two more ways to capture fall flavor in a jar.
By December, you’ll be pulling out jewel-toned jars to wrap with ribbon and share — homemade gifts that taste like fall in a jar.
Simple Living ❤️ Country Style — one jar of Omi’s kitchen at a time.
Want more ways to preserve what’s in season? Browse the full Canning & Preserving collection here.
Have you tried making this plum jam recipe yet? Did you go with Omi’s freezer version or the water bath canning method? Drop a comment below and let me know how it turned out — your tips, tweaks, and memories help make this little community even sweeter.
📬 Love recipes like this?
Subscribe to Our Country Life and get seasonal recipes, homestead tips, and canning inspiration delivered straight to your inbox.
More Recipes You’ll Love
- Farmhouse Apple Pie Jam Recipe – Cozy Fall Canning with Warm Spices
- The Best Maple Apple Butter Recipe (Stovetop, Slow Cooker, Oven + Canning Tips)
- Old-Fashioned Pickled Beets Recipe – Sweet, Tangy & Easy Canning Guide
Printable Recipe Cards
Choose your version below (both are included)— Omi’s traditional freezer plum jam for the fridge/freezer, or a safe water bath canning version for long-term storage.
Freezer Plum Jam (Omi’s German Recipe)
Ingredients
- 5 1/2 Pounds Plums
- 2 1/2 Cups Sugar (or as little as 1 1/4 cups for a more tart, traditional flavor)
- 1 Juice of Lemon or vinegar (traditional WWII substitute)
Instructions
- Wash, pit, and chop the plums (leave skins on for color and natural pectin).
- Place chopped plums in a large bowl. Add sugar and stir to combine.
- Cover and let the mixture macerate overnight at room temperature.
- The next day, transfer plums and their juices into a heavy-bottomed pot. Stir in the lemon juice.
- Bring to a boil over high heat, then reduce the heat to low. Simmer gently for about 3 hours, stirring occasionally, until thickened and glossy.
- Ladle jam into clean jars, leave ½ inch headspace if freezing.
- Cool to room temperature, then refrigerate for up to 3 weeks or freeze for up to 6 months.
Notes
- 📝 From Omi’s handwritten recipe: During and after WWII in Germany, lemons were scarce, so vinegar was sometimes used as the acid. I recommend using lemon juice if available.
- 🍬 For a sweeter jam (more in line with American palates), use the full 2 1/2 cups sugar. For a tart, old-world flavor, you can reduce to as little as 1 1/4 cups.
- 🫙 This jam is not shelf-stable. Store jars in the fridge for up to 3 weeks or freeze for up to 6 months (leave 1/2″ headspace when freezing).
- 🍇 Expect a soft, loose set — more like a fruit spread than a firm jam.
- 🔄 For a smoother texture, you can run the cooked jam through a food mill or use an immersion blender before jarring.
Plum Jam Recipe for Safe Water Bath Canning
Equipment
- Basic water bath caning equipment
Ingredients
- 5 1/2 Pounds Plums
- 4 – 5 Cups Sugar (adjust depending on plum sweetness)
- 1/4 Cup Bottled Lemon Juice
- Optional: 1 packet low/no sugar pectin (for a firmer set with less sugar)
Instructions
- Wash, pit, and chop the plums (leave skins on for color and natural pectin).
- In a large, heavy-bottomed pot, combine plums and bottled lemon juice.
- Stir in sugar (and pectin, if using).
- Bring to a full rolling boil over medium-high heat, stirring constantly.
- Cook for 20–25 minutes, or until the jam thickens to your desired consistency.
- Ladle hot jam into sterilized half-pint jars, leaving 1/4 inch headspace. Remove air bubbles and wipe jar rims clean.
- Apply lids and bands until fingertip tight.
- Process jars in a boiling water bath canner for 10 minutes (adjust for altitude if necessary).
- Carefully remove jars with a jar lifter and cool on a towel-lined surface for 24 hours, undisturbed.
- Check seals. Store sealed jars in a cool, dark pantry for up to 18 months. Refrigerate any unsealed jars and use within 3 weeks.
Notes
- 🧃 Use bottled lemon juice. Fresh lemons vary in acidity, but bottled lemon juice has a standardized pH, which is essential for safe water bath canning.
- 🍬 Adjust sugar to taste: 4 cups for a slightly tart jam, 5 cups for a sweeter, thicker jam. Using low/no sugar pectin lets you reduce sugar while still achieving a firmer set.
- 🫙 This recipe makes 7–8 half-pint jars. Store sealed jars in a cool, dark pantry for up to 18 months. Refrigerate any unsealed jars and use within 3 weeks.
- 🔄 For a smoother jam, use an immersion blender after cooking or run the plums through a food mill before jarring.
- ⛰️ Don’t forget altitude adjustments: increase processing time according to USDA guidelines (e.g., add 5 minutes for 1,001–3,000 ft).
- 🎁 This jam is perfect for holiday gifting — tie a ribbon around a jar and pair it with homemade bread, scones, or cheese.
Pin and Save for Later!
FAQs
Can I can Omi’s original recipe as written?
No — it’s too low in sugar and uses fresh lemon, which varies in acidity. Stick to fridge/freezer for the original, or adapt it for canning.
Why bottled lemon juice for canning?
It has standardized acidity, making it safe for water bath canning. Fresh lemons vary in acid levels.
When jam making, can I test the acidity of jam at home?
Only with a calibrated pH meter, and even then, ripeness and variety make results inconsistent. The USDA recommends sticking to tested recipes instead.
Can I reduce sugar in the canning version?
Yes, for low sugar jam use low/no sugar pectin for best results. Without it, your jam will be softer and may not store as long.
Can you make plum jam without pectin?
Yes! Plums are naturally high in pectin, especially if you leave the skins on. Omi’s freezer version has no added pectin, while the canning version can use it for a firmer set.
What’s the difference between plum jam, plum butter, and plum preserves?
Jam is soft and spreadable with fruit pieces.
- Butter is cooked down longer until it’s smooth and concentrated.
- Preserves often have larger chunks of fruit in syrup.
What plums are best for jam?
European plums (like Italian prune plums or Damsons) give a rich, deep flavor and natural thickness. Red or black plums make a brighter, jewel-toned jam.
Why let plums macerate overnight?
Macerating draws out juices, dissolves sugar, and develops deeper flavor before cooking. It also helps prevent scorching when the jam starts simmering.
How do you thicken plum jam if it’s too runny?
Keep simmering to cook off more liquid, or add a little powdered pectin mixed with sugar and boil again for 1–2 minutes.
Do you have to peel the plum skins for jam?
No — the skins add color, flavor, and natural pectin. Omi always left them on.
Is plum jam healthy?
Plums themselves are high in antioxidants and vitamins, but remember jam is sweetened. You can reduce sugar slightly in freezer jam or use low-sugar pectin in the canning version.
Can you water bath can plum jam without lemon juice?
No. Even though plums are somewhat acidic, the bottled lemon juice guarantees a safe acidity level for canning.
Do I need to sterilize jars for freezer jam?
Not in the same way you would for canning. Since freezer jam isn’t shelf-stable, you don’t need to boil or pressure-sterilize jars. Just wash jars (or freezer-safe containers) in hot soapy water, rinse well, and dry. For extra peace of mind, you can run them through the dishwasher on the hot cycle right before filling.
Can I run plum jam through a food mill for a smoother texture?
Yes, absolutely. If you prefer a smoother jam without bits of peel or fruit, you can run the cooked plums through a food mill or use an immersion blender before finishing the recipe. Omi always left the skins on for color, flavor, and natural pectin, but straining or blending is totally fine if you like a silky, spreadable texture. Just keep in mind that removing skins may reduce the natural pectin, so your jam could set a little softer unless you add pectin.
Final Thoughts
This homemade plum jam recipe is more than just a way to use up a mountain of plums — it’s a taste of tradition. My Omi made hers the old-world way, low on sugar and big on fruit flavor, and I still make that freezer version whenever I want to relive those memories.
But I’ve also learned the value of adapting recipes for today: a safe water bath canning version means I can line my pantry shelves with jars of jam and store them for winter breakfasts, cozy roasts, and even holiday gifts.
So if your counters are covered in plums this fall, don’t let the fruit flies win. Make a batch of jam, some for the refrigerator and freezer for right now, and put a few jars through the canner for later. By December, you’ll be pulling out jewel-toned jars to wrap with ribbon and share — homemade gifts that taste like fall in a jar.
Hi, I’m Yvonne — the voice behind Our Country Life. I share from-scratch recipes, garden know-how, and simple living inspiration rooted in real farmhouse life. Thanks for being here ❤️
Leave a Reply