Enrichment · Cultural Studies

Water boils cooler
up the mountain.

At 5,280 feet water boils near 203°F, not 212°F, so a jar spends longer getting safe. Put in the tested recipe and your altitude; the page gives the water-bath time or the canner pressure, and checks the steps that keep a batch safe.

Adjust a batchWhat you get

Your batches

The worked example is made up: tomatoes and green beans canned at 5,280 feet, and a batch of carrots that should not go in a water bath. Saved on this device only.

Loading the batch form. If nothing appears, turn on JavaScript.

What you get

Enrichment · Cultural StudiesFree

What you finish with
A record per canning batch: food, acid group, method, altitude, jar size, the tested recipe’s time and source, seven safety steps and notes. Works out the water-bath time or the dial or weighted gauge pressure for your altitude; flags a low-acid food in a water bath, altitudes above the published tables and the steps not done.
Who it is for
Home canners, gardeners, family and consumer science classes and anyone canning above 1,000 feet.
Format
Browser log with a saved record per batch. Prints a batch card for the kitchen, every batch in a table or a blank card; downloads a spreadsheet (.csv); exports and imports a file.
Access
Free. No account, no sign-in and nothing to install. Everything you type stays in this browser; nothing is sent to Caveat.
Where it lives
The Cultural Studies space in Caveat Enrichment.
Support
Questions about access, an order or a correction: team@caveatacademic.com.

How to use it

  1. Pick a tested recipe and note its time at sea level.
  2. Look up your altitude.
  3. Choose the method and jar size the recipe gives.
  4. Use the time or pressure the page works out.
  5. Check seals the next day and date every jar.

Adjust a batch

Time or pressure

The general altitude tableAltitude (feet)Water bathDial gaugeWeighted gauge0 to 1,000recipe time11 lb10 lb1,001 to 2,000+5 min11 lb15 lb2,001 to 3,000+5 min12 lb15 lb3,001 to 4,000+10 min12 lb15 lb4,001 to 6,000+10 min13 lb15 lb6,001 to 8,000+15 min14 lb15 lb8,001 to 10,000+20 min15 lb15 lbThe general altitude table0 to 1,000Water bath: recipe timeDial gauge: 11 lbWeighted gauge: 10 lb1,001 to 2,000Water bath: +5 minDial gauge: 11 lbWeighted gauge: 15 lb2,001 to 3,000Water bath: +5 minDial gauge: 12 lbWeighted gauge: 15 lb3,001 to 4,000Water bath: +10 minDial gauge: 12 lbWeighted gauge: 15 lb4,001 to 6,000Water bath: +10 minDial gauge: 13 lbWeighted gauge: 15 lb6,001 to 8,000Water bath: +15 minDial gauge: 14 lbWeighted gauge: 15 lb8,001 to 10,000Water bath: +20 minDial gauge: 15 lbWeighted gauge: 15 lb
Pressure canning times do not change with altitude; the pressure does. A tested recipe’s own altitude chart wins over this general one when they differ.

Why acid decides the method

Clostridium botulinum spores survive boiling. In high-acid food they cannot grow; in low-acid food they can, unless the jars reach 240°F, which only a pressure canner does. Tomatoes sit near the line, so tested recipes add bottled lemon juice or citric acid.

Why altitude matters

Water boils about 1°F cooler for every 500 feet of elevation. A water bath makes up for the lower temperature with more time. A pressure canner makes up for the thinner air with more pressure, so the temperature inside still reaches 240°F.

Sources

  1. National Center for Home Food Preservation. Canning at high altitudes and Selecting the correct processing time (nchfp.uga.edu).
  2. U.S. Department of Agriculture. (2015). Complete Guide to Home Canning, Agriculture Information Bulletin 539.
  3. Centers for Disease Control and Prevention. Home-canned foods and botulism (cdc.gov).
  4. Colorado State University Extension. High altitude food preparation and canning (extension.colostate.edu).

The worked example is made up. The table is the general one; always follow a tested recipe and its own altitude chart, and ask your county extension office about anything unusual. Nothing you type is sent to Caveat. Support: team@caveatacademic.com.