Fernhart Labs.

Canning altitude adjustment chart: water bath and pressure

Updated · Fernhart Labs · sources at the end

Short answer

Water boils at a lower temperature the higher you live, so the USDA guide makes water-bath times longer and pressure-canner pressures higher as altitude rises. There's no single number to add: use the row for your altitude in each food's own table.

For low-acid foods in a pressure canner: weighted gauge 10 psi up to 1,000 ft and 15 psi above; dial gauge 11 psi up to 2,000 ft, 12 to 4,000, 13 to 6,000 and 14 to 8,000 ft. Never use a lower band than yours.

Pressure canner: weighted gauge

For vegetables, meat, poultry and other low-acid foods the process time stays the same at every altitude; only the pressure changes.

Weighted gauge: pressure for low-acid foods by altitude (USDA 2015)
AltitudeWeighted gauge
0–1,000 ft10 psi
Above 1,000 ft15 psi

Dial gauge

A dial gauge that reads high gives the food less heat than you think, so have it tested every year before the season and replace it if it's off by more than 2 pounds (Guide 1, page 1-20).

Dial gauge: pressure for low-acid foods by altitude (USDA 2015)
AltitudeDial gauge
0–2,000 ft11 psi
2,001–4,000 ft12 psi
4,001–6,000 ft13 psi
6,001–8,000 ft14 psi
Above 8,000 ftNo dial-gauge figure in the guide's tables

Water bath: times by altitude, examples

Water-bath tables give a time for each altitude band, and how much it goes up depends on the food and jar. Some tables use one band for 1,001 to 6,000 ft; this chart shows that time in both middle columns. These are examples: each food's own table is in the guide and in Jarwise.

Water-bath times by altitude: examples from the USDA guide
FoodPackJar0–1,000 ft1,001–3,000 ft3,001–6,000 ftAbove 6,000 ftHeadspaceGuide page
Peaches, halved or slicedHotPint20 min25 min30 min35 min1/2 in2-19
Peaches, halved or slicedHotQuart25 min30 min35 min40 min1/2 in2-19
Peaches, halved or slicedRawPint25 min30 min35 min40 min1/2 in2-19
Peaches, halved or slicedRawQuart30 min35 min40 min45 min1/2 in2-19
ApplesauceHotPint15 min20 min20 min25 min1/2 in2-7
ApplesauceHotQuart20 min25 min30 min35 min1/2 in2-7
Tomatoes, whole or halved (packed in water)Hot or rawPint40 min45 min50 min55 min1/2 in3-9
Tomatoes, whole or halved (packed in water)Hot or rawQuart45 min50 min55 min60 min1/2 in3-9
Tomato juiceHotPint35 min40 min45 min50 min1/2 in3-5
Tomato juiceHotQuart40 min45 min50 min55 min1/2 in3-5
Apple juiceHotPint or quart5 min10 min10 min15 min1/4 in2-6
Apple juiceHotHalf-gallon10 min15 min15 min20 min1/4 in2-6

Times from the USDA Complete Guide to Home Canning (2015). Where the guide uses one band for 1,001–6,000 ft, both columns show that time.

Using your altitude safely

  • Find your altitude once (your county Cooperative Extension office can help) and use that band for every batch.
  • Never round down into a lower band: at 1,050 ft you are in the 1,001–3,000 ft band.
  • Don't apply one food's extra minutes to another food: each table was tested on its own.
  • Above 8,000 ft the guide's dial-gauge tables stop; they give no dial pressure there. (From Guide 1, page 1-22 and the guide's tables.)

Questions

How much time do you add for altitude when canning?

It depends on the food. Each USDA water-bath table gives the time for each altitude band; peaches (hot pack, pints), for example, go from 20 minutes at up to 1,000 ft to 35 minutes above 6,000 ft. Use the food's own row.

What pressure do you use for canning above 1,000 feet?

With a weighted gauge, 15 psi above 1,000 ft for low-acid foods. With a dial gauge, 12 psi at 2,001–4,000 ft, 13 at 4,001–6,000 ft and 14 at 6,001–8,000 ft (11 psi up to 2,000 ft).

Does altitude change pressure canning time?

For low-acid foods in the USDA tables, no: the time stays the same and the pressure goes up.

Why does altitude matter for canning?

Water boils at a lower temperature at higher altitudes, so food in a water bath gets less heat in the same time, and a pressure canner needs more pressure to reach the same temperature.

Jarwise: Canning Timer & Log

Canning app: USDA-tested times for your altitude, canner timer, jar log.

Jarwise has every tested food in the USDA guide. Set your altitude once and it shows the right time and pressure for your canner, with your altitude band highlighted; combinations the guide doesn't test get no time. A step-by-step timer covers venting, processing and cool-down, and a batch log and pantry keep track of your jars, offline and with no account.

Coming to Google Play

Sources

  1. USDA Complete Guide to Home Canning (2015), Guide 1: Principles of home canning (pages 1-8, 1-10, 1-13, 1-18 to 1-22) Guide 1 (PDF)
  2. USDA Complete Guide to Home Canning (2015), Guide 2: Fruit and fruit products Guide 2 (PDF)
  3. USDA Complete Guide to Home Canning (2015), Guide 3: Tomatoes and tomato products (acidification, page 3-5) Guide 3 (PDF)
  4. National Center for Home Food Preservation: the USDA Complete Guide to Home Canning, 2015 revision (current edition) nchfp.uga.edu

More guides

All guides