How to Make Plum Sauce in Canada (Water-Bath Method)
Savoury plum sauce — the tangy, spiced condiment for dipping and glazing — is safe to water-bath can because it is acidified with vinegar. Simmer pitted plums with onion, garlic, ginger, sugar, and a spice bag until thick, then add the full amount of vinegar your tested Bernardin recipe calls for. The vinegar is what keeps the sauce below pH 4.6 and safe, because the onion, garlic, and ginger are low-acid — never reduce it. Ladle hot into small Bernardin jars leaving 1 cm headspace, apply two-piece lids, and process in a boiling water bath for the time and altitude band in your recipe.
Savoury plum sauce is the best argument for planting a plum tree. Sweet, tangy, and warm with spice, it’s a dipping sauce for dumplings and spring rolls, a glaze for pork, duck, or chicken, and a stir-fry backbone — the home-canned cousin of the bottled “duck sauce” from takeout, only deeper and less sweet.
It’s also, quietly, an acidified canning recipe, which makes the safety rules stricter than a jar of canned plums. This guide follows the Bernardin water-bath method. Per our food-safety policy we cite Bernardin for the exact vinegar amount and processing time rather than reprinting them.
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Corrected 31 Aug 2026: the page put “(5% acidity)” directly beside “your tested Bernardin recipe”, which reads as though Bernardin published the percentage. This site specifies 5% acidity as our own convention — most Bernardin recipes we have verified state no acidity percentage at all, and Canadian law guarantees only 4.1% for any vinegar. Every instruction about not reducing the acid is unchanged.
Why plum sauce needs vinegar even though plums are acidic
On their own, plums are high-acid — that’s why canned plums need no added lemon juice. But plum sauce adds onion, garlic, and ginger, all low-acid, and that changes the maths:
The finished sauce is no longer reliably below pH 4.6 without help. A tested recipe adds enough vinegar to bring the whole batch safely under 4.6.
Use the full vinegar amount your tested Bernardin recipe calls for. Never reduce it to mellow the sauce.
This is the same logic as ketchup and why you can’t water-bath spaghetti sauce: low-acid vegetables are only safe in a boiling-water bath when a tested recipe acidifies the whole batch. Sugar and salt you can adjust to taste — they’re flavour, not safety. Vinegar is safety.
What you need
- About 3 kg ripe plums — Italian prune or any variety, pitted, skins on (the food mill removes the skins later)
- Onion, garlic, and fresh ginger — the aromatics that make it savoury
- Vinegar — the amount in your tested recipe, at 5% acidity (our convention, not a Bernardin figure — check the label)
- Sugar and salt to taste
- Whole spices for a spice bag — cinnamon, star anise, cloves, dried chili
- A food mill or fine sieve, and a large heavy pot
- 250 mL Bernardin jars with new SNAP lids — small jars suit a condiment used slowly
- Standard canning kit — jar lifter, headspace tool, funnel, water-bath canner, ladle (which canner to buy)
Presses the skins and pit fragments out of the simmered plums so you never peel — the same tool handles ketchup, applesauce, and berry jam. The default Canadian pick for a fruit glut.
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Check price on Amazon.ca →The method (mostly hands-off simmering)
- Simmer the fruit and aromatics. Combine pitted plums, onion, garlic, ginger, sugar, and the tied spice bag in a heavy pot. Simmer, stirring often, until the plums collapse — about 30–40 minutes.
- Sieve. Remove the spice bag, then press everything through a food mill to remove skins and pit fragments. Return the smooth sauce to the pot.
- Reduce. Simmer uncovered, stirring often, until it’s a pourable sauce — another 30–60 minutes.
- Acidify. Stir in the full amount of vinegar your recipe specifies. Simmer a few minutes to blend.
- Fill. Ladle hot sauce into hot 250 mL jars, leaving 1 cm (½ inch) headspace. Wipe rims, apply fresh SNAP lids fingertip-tight.
- Process in the boiling water bath for the time in your Bernardin edition for plum sauce, at your altitude band. Time starts at a full rolling boil.
- Cool and check. Rest 5 minutes in the canner, lift to a towel, and leave 24 hours before checking seals.
Common questions
It’s still thin after an hour. Keep going — plum sauce reduces as the water cooks off. Never thicken with starch for canning; it blocks heat penetration. Reduce further in the pan after opening if a dish needs it thick.
A jar didn’t seal. Refrigerate and use within a few days (Bernardin’s figure), or reprocess immediately with a fresh lid. See jar didn’t seal — is it safe.
How long does it keep? Sealed, cool, and dark, about a year for best quality. See how long home-canned food lasts.
Ways to use plum sauce
- Dipping sauce for spring rolls, dumplings, and egg rolls
- Glaze brushed on roast pork, duck, chicken, or ribs
- Stir-fry sauce base with soy and sesame
- Sandwich or wrap spread
- Alongside a cheese board
Next steps
- How to can plums in syrup — the sweet, no-added-acid preserve
- How to make plum jam — skins on for pectin
- How to make tomato ketchup — the same vinegar-safety logic
- Canning altitude adjustments — required reading
- How long does home-canned food last — shelf-life context
- Water-bath canning pillar — the broader method
Altitude adjustment
Process times in a boiling-water canner are written for altitudes up to 305 m. Above that, water boils below 100 °C and the time printed in the recipe is no longer enough. Find your elevation, then add the minutes Bernardin publishes for that band.
| Elevation (m) | Elevation (ft) | Add to processing time |
|---|---|---|
| 0 – 305 | 0 – 1,000 | None — use the recipe time as written |
| 306 – 915 | 1,001 – 3,000 | +5 minutes |
| 916 – 1,830 | 3,001 – 6,000 | +10 minutes |
| 1,831 – 2,440 | 6,001 – 8,000 | +15 minutes |
| 2,441 – 3,050 | 8,000 – 10,000 | +20 minutes |
On the line between two bands, round up to the higher one. Slightly over-processing is safe; under-processing is not.
Bernardin’s published tables stop at 3,050 m.
Find your Canadian city · Full altitude guide
Figures from Bernardin, “How do I can at a high altitude?” (bernardin.ca). Confirm against your own Bernardin edition before you start — a book edition and the website can differ.
Frequently asked questions
What makes plum sauce safe to water-bath can?
The vinegar. Whole plums are high-acid on their own, but savoury plum sauce also contains onion, garlic, and ginger — all low-acid — so the finished sauce is no longer reliably below pH 4.6 without help. A tested plum sauce recipe adds enough vinegar to bring the whole batch safely under pH 4.6, which is what makes the boiling-water method safe. This is why you must use a tested Bernardin recipe and never reduce the vinegar: cutting it for a mellower taste can quietly turn a safe batch into an unsafe one. It's the same rule as ketchup and chili sauce.
Is this the same as the plum sauce from Chinese takeout?
It's the home-canned cousin. Bottled Chinese-restaurant plum sauce (or duck sauce) is the inspiration — sweet, tangy, spiced — but a canning recipe balances the acidity for safe shelf storage. Homemade plum sauce is deeper and less cloying, excellent as a dipping sauce for spring rolls and dumplings, a glaze for pork, duck, or chicken, or a stir-fry base. Use a tested Bernardin recipe rather than adapting a stovetop restaurant recipe, so the vinegar level is right for canning.
Do I have to peel the plums for plum sauce?
No. The sauce is puréed or pressed through a food mill at the end, which removes the skins and any pit fragments, so there's no need to peel first. Simmering the plums whole (pitted) with their skins on actually deepens the colour and flavour. Just wash them, cut them off the pits, and simmer — the food mill does the rest. This is much less work than peeling.
Why won't my plum sauce thicken?
Plum sauce thickens by evaporation, and it takes time — a batch reduces noticeably as the water cooks off, often an hour or more of gentle simmering with frequent stirring. Starting with meatier plums and keeping the heat at a steady simmer speeds it up. Don't thicken with cornstarch or flour for canning — starches slow heat penetration and aren't safe in home-canned foods. If you want it thicker for a specific dish, reduce a jar's worth on the stove after you open it.
Sources
- Bernardin Complete Book of Home Preserving (latest edition)
- Health Canada — Home canning safety (https://www.canada.ca/en/health-canada/services/general-food-safety-tips/home-canning-safety.html)
- OMAFRA — Plum production and preservation