Adjustments are critical for food safety at higher elevations!
The processing time (for water bath canning), pressure requirement (for pressure canning) and blanching time (for freezing and drying some foods) all need to be increased at higher elevations to destroy heat-resistant bacteria and to ensure home-preserved food products are safe to enjoy.
- Because water and other liquids boil at a lower temperature as elevation increases (for example, at sea level water boils at 212 degrees F, while at 5,000 feet water boils at 203 degrees F) it is critical to know your elevation to make accurate food preservation adjustments.
Important Steps for Safely Preserving Foods at High Elevation
1. Determine your elevation using a resource such as whatismyelevation.com (Enter your address, city, and state in the 'Enter your location' box.)
2. Use tested recipes and follow all high elevation adjustment instructions provided (sometimes referred to as high altitude adjustments)--including processing time, required equipment, pressure, and blanching time.
- All recipes in Preserve Smart provide research-based elevation adjustment information as determined by Colorado State University Extension and/or the National Center for Home Food Preservation--established with funding from the Cooperative State Research, Education and Extension Service, U.S. Department of Agriculture (CSREES-USDA).
- When processing adjustments for your elevation are not provided with a recipe, water bath and/or pressure canning are NOT recommended as safe food preservation methods. Consider, instead, preserving by freezing or dehydrating.
3. To further minimize the risk of botulism poisoning, before tasting or serving, boil all home-canned, low-acid vegetables for a full 10 minutes at elevations below 1,000 feet. For elevations above 1,000 feet, add an additional minute of boiling time for each additional 1,000 feet. (Ex. at 5,000 feet boil for 15 minutes)
For more information on high elevation cooking adjustments read CSU Extension's High Altitude Food Preparation Guide.