How to Can Tomatoes in Canada (Bernardin Method)

Home-canned tomatoes are the gateway recipe for serious Canadian preservers. Done right, a jar from August keeps you in pasta sauce, chili base, and tomato soup until next year’s harvest. Done wrong — without acidification — they’re one of the highest-risk foods in home canning.

This guide follows two Bernardin recipes and gives both processing times in full: Whole or Halved Tomatoes (hot-packed in tomato juice) and Crushed Tomatoes. They are genuinely different recipes — different method, different headspace, and times that are not remotely close — so pick one before you start and follow it through.

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The single most important rule: acidify every jar

Bernardin’s tomato canning recipes all open with the same line, and we will too:

Add 1 tbsp bottled lemon juice per 500 mL jar, or 2 tbsp per 1 L jar. Alternative: ¼ tsp citric acid per 500 mL, or ½ tsp per 1 L.

This goes in every jar, every time, regardless of variety, regardless of whether the tomatoes taste tart. Modern tomato cultivars sit close to the pH 4.6 threshold that divides high-acid (water-bath safe) from low-acid (pressure-canning required). Adding lemon juice or citric acid pushes the contents reliably under 4.6 — which is what makes the water-bath method safe at all.

Bottled lemon juice only. Fresh lemon juice varies in acidity from lemon to lemon and is not safe here.

What you need

• 4.5–5 kg (10–11 lb) ripe paste tomatoes — Roma, San Marzano, Amish Paste. Beefsteaks work but yield more water and less pulp.
• Boiling water bath canner (a tall stockpot with a rack works)
• 7 × 500 mL Bernardin jars, or 3–4 × 1 L jars, plus new SNAP lids and bands
• Bottled lemon juice OR food-grade citric acid
• A large bowl of ice water for the peel-loosening dip
• A jar lifter, lid magnet, and headspace tool (the Bernardin canning kit covers all three)

Method (Bernardin-aligned)

1. Heat the canner. Fill the canner with enough water to cover the jars by 2.5 cm (1 inch). Bring to a simmer while you prep the tomatoes.

2. Sterilize the jars. Heat empty jars in simmering water (not boiling) — they’re ready to fill when they come out hot. Lids no longer need to be heated under Bernardin’s current SNAP-lid guidance, but rims still need to be clean.

3. Score and dip the tomatoes. Cut a shallow X in the bottom of each tomato. Dip in boiling water for 30–60 seconds until skins start to crack, then transfer to ice water. Slip off the skins with your fingers.

4. Core and quarter. Remove the cores and any green or bruised flesh.

5. Cook them — and here the two recipes part company.

   Whole or halved: leave the tomatoes whole or halve them. Put them in a large stainless steel saucepan, add enough tomato juice to cover, bring to a boil and boil gently for 5 minutes. Juice, not water — the fill medium is part of the recipe, and it is what the 85-minute time was tested with.

   Crushed: put 2 cups (500 mL) of tomato quarters in the saucepan and bring to a boil while crushing and stirring, to draw the juice out. Boil gently, stirring constantly, and add the rest 2 cups at a time. Do not crush the later additions — Bernardin is explicit about this, and the reason is that they soften on their own with the heat and the stirring. Once everything is in, boil gently 5 minutes.

   Crushing only the first batch is what stops the jar separating into pulp and water. Mashing the whole pot at once releases an enzyme that breaks the pectin down before the heat can stop it.

6. Acidify each jar. Add lemon juice or citric acid directly to each empty hot jar in the amount above. Every jar. Don’t try to add it to the pot — it needs to be measured per jar.

7. Pack.

   Whole or halved: pack the hot tomatoes into the jars to within 2 cm (¾ inch) of the rim, then ladle hot tomato juice over them to cover, leaving 1 cm (½ inch) headspace. Those are two different measurements and it is worth being clear about it: 2 cm is how high the tomatoes come, and 1 cm is the finished headspace once the juice is in.

   Crushed: ladle straight into the jar to within 1 cm (½ inch) of the rim. One measurement — the crushed tomatoes bring their own liquid, so there is nothing to top up.

   Either way, add the optional salt — ½ tsp per 500 mL jar, 1 tsp per 1 L — to the jar before filling if you want it. Salt here is flavour, never a safety factor.

8. Debubble. Run a non-metallic spatula or chopstick around the inside of each jar to release trapped air. Re-check headspace.

9. Wipe the rims. Clean the rim of each jar with a damp cloth — any residue blocks the seal.

10. Apply lids. Centre a SNAP lid on each jar, then a band fingertip-tight (not over-tight; the air needs to escape during processing).

11. Process — and check which recipe you’re on. Lower the jars in with a jar lifter and make sure they’re covered by 2.5 cm of water. Bring to a full rolling boil, then start timing. Whole or halved: 85 minutes, any jar size. Crushed: 35 minutes for 500 mL, 45 minutes for 1 L. Both at altitudes up to 305 m; above that, add the Bernardin boiling-water increment for your band — the table is at the foot of this page, and our altitude-adjustments guide explains it. Verify against your Bernardin edition before you start.

12. Cool and check. Turn off the heat, wait 5 minutes, then lift the jars out without tilting them and stand them upright on a towel-lined counter. Let them cool undisturbed for 24 hours, and do not retighten the bands. The lids should “ping” as they seal. After cooling, press the centre of each lid — no give means a good seal.

If a jar didn’t seal: refrigerate and use within a week, or freeze. Never re-process a failed seal more than once, and never reuse a SNAP lid.

Bernardin’s processing times

Both in a boiling-water canner, at altitudes up to 305 m:

Recipe	500 mL	750 mL	1 L
Whole or halved, hot-packed in juice	85 min	85 min	85 min
Crushed	35 min	—	45 min

Read that table twice before you start. Whole tomatoes in juice take nearly two and a half times as long as crushed, and the 500 mL and 1 L figures behave in opposite ways: whole is the same time for every jar size, crushed is not. There is no way to reason your way to those numbers from first principles — they come off the two recipe pages and nowhere else.

The whole/halved row being flat across all three sizes is genuinely unusual, and worth stating because it is exactly the kind of figure people assume they have misread. Bernardin also publishes a 750 mL jar for that recipe; there is no 750 mL row for crushed.

Above 305 m you add minutes, not pressure — the boiling-water table is at the foot of this page, and our altitude-adjustments guide explains how the bands work. If you’re not sure which band you’re in, look up your city.

These two times cover these two recipes and nothing else. Raw pack, tomato juice, tomato sauce and salsa are separate Bernardin recipes with their own directions and their own times — we have not verified those pages yet, so for those, open your edition.

Storage and shelf-life

• Cool, dark place. A pantry or basement shelf. Avoid temperature swings.
• Best within 12 months, which is Bernardin’s guidance for home-canned food. Sealed jars stay safe longer if the seal holds, but flavour and texture decline. Date your jars.
• Inspect before opening. Any bulging lid, off smell, foaming on opening, or visible mould = discard the entire contents without tasting. This is the boring rule that keeps the safety record clean.

What not to do

• Don’t skip the lemon juice or citric acid. It is not optional, even if you grew the tomatoes yourself and they taste tart.
• Don’t water-bath can tomato sauces with onions, peppers, or meat. Those become low-acid mixtures. Either use a tested high-acid salsa recipe with added vinegar, or pressure can a tested mixed recipe.
• Don’t use cracked or overripe tomatoes. They can carry mould the heat won’t fully kill.
• Don’t reuse SNAP lids. Bands, yes; lids, no.
• Don’t process for shorter than published. If you saved 30 seconds at processing, eat it within a week from the fridge instead of storing it.

Next steps

• Read the altitude-adjustments guide to find your band.
• Skim the water-bath canning pillar page for the broader context on which foods can be water-bath canned.
• For non-canning preservation: how to dry tomatoes in Canada (dehydrator or oven) and how to make fermented green tomatoes in Canada for the unripe end-of-season harvest.