Canning Jar Sterilization Time at Altitude Calculator
Calculate boiling-water and pressure canning sterilization times by altitude.
Get adjusted minutes for safe processing of pickles, jam, tomatoes, and meats.
Adjusted Processing Time
Canning Sterilization Time at Altitude
Water boils at lower temperatures at higher altitudes — so processing times must be extended to maintain sterilization safety.
Boiling Water Bath (BWB) altitude adjustments (USDA standards):
| Altitude (ft) | Add to Sea-Level Time |
|---|---|
| 0-1,000 ft | No adjustment |
| 1,001-3,000 ft | +5 min |
| 3,001-6,000 ft | +10 min |
| 6,001-8,000 ft | +15 min |
| 8,001-10,000 ft | +20 min |
Pressure Canning altitude adjustments (PSI changes, NOT time):
| Altitude (ft) | Weighted Gauge | Dial Gauge |
|---|---|---|
| 0-1,000 | 10 PSI | 11 PSI |
| 1,001-2,000 | 15 PSI | 11 PSI |
| 2,001-4,000 | 15 PSI | 12 PSI |
| 4,001-6,000 | 15 PSI | 13 PSI |
| 6,001-8,000 | 15 PSI | 14 PSI |
| 8,001-10,000 | 15 PSI | 15 PSI |
Common processing times (sea level baseline):
| Food | Method | Pints | Quarts |
|---|---|---|---|
| Tomatoes (acidified) | BWB | 40 min | 45 min |
| Whole tomatoes | BWB | 35 min | 45 min |
| Pickles (refrigerator) | BWB (raw pack) | 10 min | 15 min |
| Pickles (cucumber, brine) | BWB | 10-15 min | 15 min |
| Jam / jelly | BWB | 10 min | 15 min |
| Salsa (acidified) | BWB | 15 min | 20 min |
| Apple butter / fruit butter | BWB | 5 min | 10 min |
| Green beans | Pressure | 20 min | 25 min |
| Carrots | Pressure | 25 min | 30 min |
| Corn (whole kernel) | Pressure | 55 min | 85 min |
| Beef chunks | Pressure | 75 min | 90 min |
| Chicken | Pressure | 75 min | 90 min |
| Chili / soup | Pressure | 60 min | 75 min |
Safety rules — never violate:
- Acidic foods (pH below 4.6 — fruits, jams, properly pickled vegetables) can use BWB
- Low-acid foods (vegetables, meats, soups) MUST use pressure canning — botulism risk
- Tomatoes need acidification (lemon juice or citric acid) for safe BWB processing
- Always start counting after the water reaches a full rolling boil (BWB) or vent + pressurize properly (pressure canner)
Water bath setup:
- Water must cover jar lids by at least 1 inch
- Process timer starts when water returns to a full rolling boil after jars are added
- Cool slowly (don’t quench) — sudden temperature changes crack jars
Pressure canning setup:
- Vent canner for 10 full minutes before pressurizing (purges air)
- Allow pressure to drop to 0 PSI naturally before opening (do NOT release manually)
- Wait 10 min before removing lid
Common altitude regions:
- Denver, CO: ~5,280 ft (BWB +10 min, pressure 13 PSI dial)
- Mexico City: ~7,350 ft (BWB +15 min, pressure 14 PSI dial)
- Cuzco, Peru: ~11,150 ft — exceeds standard tables; consult local extension office
- New Orleans: 1 ft (no adjustment)
- Chicago: 600 ft (no adjustment)