How long to water bath can jam
Process jam for 10 minutes (half-pints and pints) in a boiling-water canner at 0–1,000 ft, then add minutes as altitude rises: +5 at 1,001–3,000 ft, +10 at 3,001–6,000 ft, +15 at 6,001–8,000 ft and +20 at 8,001–10,000 ft.
Jam canning times by altitude
| Altitude | Half-pints and pints |
|---|---|
| 0–1,000 ft | 10 min |
| 1,001–3,000 ft | 15 min |
| 3,001–6,000 ft | 20 min |
| 6,001–8,000 ft | 25 min |
| 8,001–10,000 ft | 30 min |
What the time assumes
- Method: boiling-water (water bath) canner
- Acidity: high-acid (or acidified)
- Headspace: ¼ inch
- No tested process: quarts and half-gallons. Putby shows no time for these sizes.
Jams are made from a tested recipe; if your recipe gives a longer time, use it. There is no tested quart process for jam.
Questions
- How long do you water bath can jam?
- Process jam for 10 minutes (half-pints and pints) in a boiling-water canner at 0–1,000 ft, then add minutes as altitude rises: +5 at 1,001–3,000 ft, +10 at 3,001–6,000 ft, +15 at 6,001–8,000 ft and +20 at 8,001–10,000 ft.
- How long do you process jam at 5,000 feet?
- 20 minutes for half-pints and pints at 3,001–6,000 ft: the 10-minute tested time plus 10 minutes for altitude.
- What headspace should I leave for jam?
- Leave ¼ inch of headspace.
Sources
- USDA Complete Guide to Home Canning, Guide 7 (Jams & Jellies) · NCHFP
Times and pressures are restated from the National Center for Home Food Preservation and the USDA Complete Guide to Home Canning, in our own words. They are the same table Putby's app uses; a test in the app fails if the two ever disagree. Altitude schedule: Putby adds minutes to boiling-water processes in five steps up to 10,000 ft; at the higher steps that can be a few minutes longer than a food's own USDA altitude table, never shorter. If your tested recipe gives a longer time, use the recipe's time. Last reviewed 2026-10-16.