Canning plums is a water-bath project. Plums are acidic enough to process in a boiling-water canner, so you do not need a pressure canner for plain canned fruit. What you do need is the right fruit, a packing method that matches how you will use the jars, and the official processing times for your altitude.
A full canner load takes about 9 pounds of plums for 9 pints, or 14 pounds for 7 quarts. That is roughly 1 to 1½ pounds per pint and about 2 pounds per quart. The National Center for Home Food Preservation and USDA home-canning guidance treat whole or halved plums the same way: hot pack or raw pack, ½-inch headspace, then process by jar size and elevation.
This guide covers choosing fruit, deciding whether to pit, picking a packing liquid, hot pack versus raw pack, processing times, and the problems that show up after the jars cool.
What Canned Plums Are For
Canned plums are not jam. They are fruit in liquid: whole or halved, packed in syrup, juice, or water. Open a jar later for yogurt, oatmeal, pork or chicken, cobbler, cake filling, or a quick sauce if you simmer the fruit down.
If you want a spread, can jam or preserves with a tested recipe. Those use different sugar ratios, headspace, and processing times. Do not treat this fruit-in-syrup method as a shortcut for jam.
Choose Plums That Can Survive Heat
Use fruit that is ripe enough to eat but still firm. Soft, overripe plums collapse in the jar and turn the syrup cloudy. Green, underripe fruit stays sour and can taste harsh after processing.
Look for:
- Deep, even color for the variety
- Intact skins with no rot, insect damage, or large bruises
- Fruit that yields slightly when pressed, not mushy
Most mature dessert plums can be canned. Freestone types (the pit pulls away cleanly) are easier if you want halves. Clingstone types work whole. Extension sources often name Italian, Early Italian, Green Gage, Yellow Egg, Brooks, and similar cooking plums as good canning choices because they hold shape.
Do not mix badly damaged fruit into the jars. Cut out small bruises if the rest of the plum is sound. Discard anything moldy.
Whole, Halved, or Pitted
You have three practical options.
Whole, unpitted. Fastest. Prick each plum on two opposite sides with a fork so steam can escape and the skins are less likely to split. Official procedures allow whole plums with pits. Intact pits are not a canning-safety problem; the concern with stone-fruit pits is crushed kernels, not a whole pit sitting inside a jar. Still, warn anyone eating from the jar that pits are present.
Halved and pitted. Best everyday option. Easier to pack, easier to eat, no surprise pits in a cobbler. Freestone plums twist apart; clingstones take more knife work.
Whole and pitted. Possible on larger fruit, but messy. Not worth it unless you have a plum pitter and patience.
You do not need to peel plums for canning. Skins add color and body. Some wild or very tart skins taste bitter; if that bothers you, use those plums for cooked jam instead of whole-fruit jars.
Hot Pack or Raw Pack
Both methods are approved. They are not equal in quality.
Hot pack is the better default. You heat the plums in boiling water, juice, or syrup for 2 minutes, cover the pot, and let them stand 20 to 30 minutes. Then you pack the hot fruit and hot liquid. Heating drives out air, so the fruit shrinks before it goes in the jar. You get fuller jars, less floating, and better color. Extension publications call this the recommended method.
Raw pack is faster: pack raw fruit firmly, then pour on boiling liquid. The fruit still cooks in the canner, so it shrinks after the lid is on. That is why raw-pack jars often look half empty, with a raft of fruit at the top. Processing time is the same. Choose raw pack only if you are short on time and can live with floating fruit.
| Hot pack | Raw pack | |
|---|---|---|
| Work | Extra 20–30 minutes on the stove | Faster to jar |
| Jar fill after cooling | Fuller | Often a large gap |
| Floating fruit | Less common | Common |
| Texture | Slightly more cooked | Slightly firmer going in, then shrinks |
| Processing time | Same | Same |
If this is your first batch, hot pack.
What Liquid to Pack Them In
Sugar does not make canned plums safe. Acidity plus heat processing does. Sugar helps color, flavor, and texture. You can pack plums in:
- Very light, light, medium, or heavy syrup
- Apple juice or white grape juice
- Plain boiling water
Water-packed plums are safe but often taste washed out because fruit sugars move into the liquid. Juice keeps some fruit character without as much added sugar. Syrup gives the most consistent pantry product.
NCHFP lists plums among fruits commonly packed in heavy syrup, but also notes that many of those fruits taste good in lighter syrups. A very light or light syrup is a sensible starting point unless your plums are very tart.
Syrup amounts for a full canner load
Heat water and sugar until the sugar dissolves and the mixture boils. Keep it hot.
| Syrup | Approx. sugar | 9-pint load | 7-quart load |
|---|---|---|---|
| Very light | 10% | 6½ cups water + ¾ cup sugar | 10½ cups water + 1¼ cups sugar |
| Light | 20% | 5¾ cups water + 1½ cups sugar | 9 cups water + 2¼ cups sugar |
| Medium | 30% | 5¼ cups water + 2¼ cups sugar | 8¼ cups water + 3¾ cups sugar |
| Heavy | 40% | 5 cups water + 3¼ cups sugar | 7¾ cups water + 5¼ cups sugar |
You may replace up to half the sugar with mild honey or light corn syrup. Do not invent a low-sugar “preserve” by cutting sugar in a jam recipe and then using these fruit-canning times. That is a different product.
Spices such as a cinnamon stick or star anise in the jar are a flavor choice, not a safety step. Keep additions small so they do not crowd the headspace or interfere with the seal.
Equipment You Actually Need
- Water-bath canner or a deep pot with a rack
- Pint or quart canning jars, new lids, reusable rings
- Jar lifter, funnel, bubble remover or thin spatula
- Large saucepan for syrup and hot packing
- Clean towels
Jars must be clean. If the processing time is 10 minutes or more, separate boiling-water sterilization of empty jars is not required; washing and keeping them hot is enough. Preheat the canner water to about 140°F for raw pack or 180°F for hot pack so the jars are not shocked by a huge temperature swing.
Step-by-Step: Canning Plums
1. Prep the fruit
Wash plums under running water. Remove stems. For whole fruit, prick two sides. For halves, cut along the seam, twist, and lift out the pit. Keep prepared fruit in a bowl so it does not sit in standing wash water.
2. Heat the packing liquid
Make syrup, or bring juice or water to a boil. For hot pack, you will use this same pot for the fruit.
3. Hot pack (recommended)
Add plums to the boiling liquid. Return to a boil and cook 2 minutes. Turn off the heat, cover, and let stand 20 to 30 minutes. The stand time is part of the tested method, not an optional rest.
4. Fill the jars
Keep jars hot. Pack plums in, then cover with the hot cooking liquid, leaving ½ inch headspace. For raw pack, pack raw fruit firmly first, then add boiling liquid to the same headspace.
Run a spatula around the inside of the jar to release trapped air. Recheck headspace and add liquid if needed. Fruit should stay below the liquid line as much as possible.
5. Lid the jars
Wipe rims with a clean, damp cloth. Sticky rims are a common reason lids fail. Apply lids and screw rings fingertip tight—snug, not cranked down. Over-tightening can prevent air from venting and lead to buckling or poor seals.
6. Process in boiling water
Lower jars onto the rack. Water must cover the lids by 1 to 2 inches. Put the canner lid on. Bring to a full rolling boil, then start the timer.
Boiling-water canner times for whole or halved plums (hot or raw pack):
| Jar size | 0–1,000 ft | 1,001–3,000 ft | 3,001–6,000 ft | Above 6,000 ft |
|---|---|---|---|---|
| Pints | 20 minutes | 25 minutes | 30 minutes | 35 minutes |
| Quarts | 25 minutes | 30 minutes | 35 minutes | 40 minutes |
Look up your elevation. Using sea-level times in the mountains under-processes the jars.
If you prefer a pressure canner, NCHFP-style tables process pints or quarts for 10 minutes at 6–9 pounds on a dial gauge (by altitude) or 5 pounds (0–1,000 ft) / 10 pounds (above 1,000 ft) on a weighted gauge. Water bath is the usual method for this product.
7. Cool without rushing
When the time is up, turn off the heat. Wait 5 minutes before lifting jars out. That pause reduces siphoning—the syrup that leaks out when jars are yanked from a hard boil into cool air.
Set jars on a towel, upright, with space between them. Leave them undisturbed 12 to 24 hours. Do not retighten rings while they are hot.
8. Check seals and store
A sealed lid is concave and does not flex when pressed in the center. Remove the rings, wash the jars, label with the date and pack style, and store in a cool, dark, dry place. Keep rings off during storage so you can spot a failed seal later.
Quality is best within about a year. Unsealed jars go in the refrigerator and should be eaten soon.
How Canned Plums Should Look After They Cool
Expect:
- Fruit that has softened
- Liquid that picks up color from the skins
- Some fruit at the top, especially with raw pack
- A small headspace bubble that is still, not actively fermenting
Floating fruit is a quality issue, not automatic spoilage. Spoilage signs are a broken seal, spurting liquid, mold, off smell, or fizzing when opened. When in doubt, throw it out. Do not taste from a suspect jar.
Problems That Show Up After Canning
Fruit floats. Raw pack, loose packing, or very ripe fruit. Use hot pack and pack snugly without crushing.
Syrup leaks during processing (siphoning). Jars were overfilled, bubbles were not removed, rings were too tight, or jars were pulled from a rolling boil with no 5-minute rest. If the seal holds and the fruit stays covered or mostly covered, the jar is still usable; wipe it and watch the seal.
Jars do not seal. Dirty rims, nicked jar mouths, reused lids, under-tight or over-tight rings, or not processing long enough for your altitude. Use a new lid and reprocess within 24 hours, or refrigerate.
Fruit looks pale or tastes bland. Water pack, or very light syrup on tart fruit. Next time use juice or a light-to-medium syrup.
Skins split or fruit falls apart. Fruit was overripe, or whole plums were not pricked. Halves from firm fruit hold up better.
Bitter aftertaste. Variety and skin, not a canning error. Use those plums for cooked jam, or peel a test batch before you commit a full canner load.
Failed sealed jars of plain canned plums can be cooked into a tested jam or sauce and processed again with new lids, as long as the fruit still smells and looks sound. Do not reprocess the same lids.
What Not to Do
- Do not skip altitude adjustments.
- Do not can mashed, thickened, or butter-style plum pulp with these times. Dense products need tested recipes of their own.
- Do not add thickeners, butter, or untested low-sugar gel mixes to fruit jars.
- Do not use oven canning, dishwasher “canning,” or open-kettle canning (filling jars and skipping the water bath).
- Do not use decorative jars that are not made for home canning.
How to Use a Jar of Canned Plums
Drain or keep the syrup, depending on the dish.
- Spoon over oatmeal, yogurt, or ice cream
- Bake into cobbler, crisp, or upside-down cake
- Simmer with a splash of vinegar and mustard for pork or roast chicken
- Puree with the packing liquid for a quick sauce
- Reduce the syrup for pancakes or drinks
If you canned them whole with pits, pit them at the table or before baking.
Frequently Asked Questions
Do I have to use sugar? No. Water or unsweetened juice is safe for this product. Texture and flavor will be flatter. Sugar is for quality, not botulism control in high-acid fruit.
Can I can wild or foraged plums the same way? Yes if they are true plums, sound, and ripe. Taste a few first. Very small, very tart fruit often makes better jam than whole canned fruit.
Can I mix plum varieties in one jar? Yes if they are all plums and similar ripeness. Mixing soft and firm fruit gives uneven texture.
Why do some charts say 25 minutes for pints? USDA and NCHFP boiling-water times for plums are 20 minutes for pints and 25 for quarts at 0–1,000 feet, with increases at higher elevations. Use that set unless your local extension publishes a different tested table for a different product.
How long do sealed jars last? Use within a year for best color and texture. After that they may still be safe if the seal is intact and there are no spoilage signs, but quality drops.
Is pressure canning better? Not for this fruit. It is optional and shorter, but water bath is the standard, simpler method for plums.
Canning plums well is less about special tricks than about firm fruit, hot pack, ½-inch headspace, and the clock that matches your elevation. Do those four things and the jars on the shelf will look closer to what you put in them.