How to Can Plums in Canada (Bernardin Method)

Plums are the easiest tree fruit to can in Canada — easier than peaches, because you skip the blanch-and-peel step and, crucially, you skip the acidification math too. A jar of canned prune plums in light syrup is a February dessert waiting to happen: spooned over yogurt, baked into a cake, or eaten straight from the jar.

This guide covers the Bernardin water-bath method. Per our food-safety policy we cite Bernardin for exact processing times rather than reprinting them — keep your edition open beside this page.

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The good news: plums don’t need added acid

This is the one place plums are genuinely simpler than peaches. Peaches and tomatoes sit right on the pH 4.6 line — the boundary between high-acid (water-bath safe) and low-acid (pressure canning required) — so they must be acidified with bottled lemon juice in every jar.

Plums are naturally high-acid. They sit comfortably below pH 4.6 on their own, so canned plums in syrup need no added lemon juice for safety.

That’s the same acidity that makes plum jam set so reliably. You still follow a tested Bernardin recipe for the jar size, headspace, and processing time — but there’s no acid to measure into each jar.

Pick your plums

• Italian prune plums (aka prune plums) — the Canadian canning standard. Freestone, firm, sweet-tart, hold their shape. Best halved.
• Damson — small, tart, excellent for canning and later baking.
• Burbank and Japanese-type plums — juicier and softer; best raw-packed whole-and-pricked.
• Prairie hardy (Pembina, Brookgold) — smaller but can well on the Prairies.

Choose plums that are ripe but still firm. Soft, dead-ripe plums turn to mush in the jar.

For 6 × 1 L jars you need roughly 4.5–5.5 kg of plums.

What you need

• 4.5–5.5 kg ripe but firm plums
• Granulated sugar and water for syrup (see the table)
• Bernardin 500 mL or 1 L jars, fresh SNAP lids, bands
• Standard canning kit — jar lifter, headspace tool, funnel, water-bath canner, ladle
• A clean needle or skewer if canning plums whole

Choose your syrup

Syrup	Sugar	Water	Notes
Light	2.25 cups	5.25 cups	Lets the plum flavour lead; the Canadian default
Medium	3.25 cups	5 cups	Sweeter, dessert-leaning
Water-packed	0	6 cups	No sugar; softer texture but safe (plums are already acidic)
Juice-packed	Unsweetened apple or white grape juice	—	Substitute 1:1 for syrup; good for lower-sugar diets

This recipe assumes light syrup, which lets the plums lead. Combine sugar and water, bring to a simmer, and keep hot until you pack.

Whole or halved?

• Whole plums — less work, beautiful in the jar. You must prick each plum in several places with a clean needle so the skins don’t burst and the fruit doesn’t float. Best for clingstone and Japanese-type plums.
• Halved and pitted — packs more fruit, holds shape, easier to use. Best for freestone Italian prune plums. Cut along the seam, twist apart, lift out the pit.

Method

1. Warm the jars and canner. Fill the canner, bring to a simmer, and heat the jars so they don’t crack when filled.
2. Prep the plums. Wash. Prick whole plums all over, or halve and pit freestone plums.
3. Make the syrup. Simmer sugar and water until dissolved; keep hot.
4. Hot-pack (recommended). Heat the plums in the hot syrup for 1–2 minutes, then pack into jars. (Raw-pack also works: pack raw plums, cover with hot syrup.)
5. Fill. Pack plums into hot jars, pour hot syrup to cover, leaving 1 cm (½ inch) headspace. Debubble; wipe rims; apply fresh SNAP lids fingertip-tight.
6. Process in the boiling water bath for the time in your Bernardin edition for plums, at your altitude band. Time starts at a full rolling boil.
7. Cool and check. Rest 5 minutes in the canner, lift to a towel, and leave 12–24 hours before checking seals.

If a jar doesn’t seal: the 24-hour rule applies.

Storage

• Cool, dark, dry place at room temperature
• Best quality 12–18 months
• After opening: refrigerate, use within 5–7 days
• Inspect before opening — discard any jar with a bulging lid or off smell

Common problems

• Plums floated to the top. Normal and cosmetic. Hot-pack and snug packing reduce it. Safe regardless.
• Skins split and slipped off whole plums. They weren’t pricked, or the syrup was too hot too fast. Prick next time; heat gently. Still safe.
• Plums mushy. Too ripe to start, or over-processed. Use firmer fruit and process for exactly the recipe time.
• Jar didn’t seal. The 24-hour rule.

Ways to use canned plums

• Spooned over yogurt, oatmeal, or ice cream with a little syrup
• Baked into a plum cake or crumble in the depths of winter
• Alongside roast pork or duck
• Puréed into a quick sauce for pancakes
• Eaten straight from the jar

Next steps

• How to make plum jam — same fruit, skins on for pectin
• How to make plum sauce — the savoury, vinegar-acidified condiment
• How to can peaches in syrup — the stone-fruit companion (which does need lemon juice)
• Canning altitude adjustments — required reading
• How long does home-canned food last — shelf-life context
• Water-bath canning pillar — the broader method