Introduction to How Altitude Affects Food Preservation: Canning Basics
Updated: Oct 25
Did you know that living by the sea or in the mountains affects your food preservation? When processing at high altitudes, adjust processing times and pressure accordingly.
There are safety guidelines a home canner needs to follow when canning. An important one often overlooked is checking your need to adjust for altitude (also known as elevation).
Altitude or elevation affects the boiling point of water. When canning in altitudes 1,000 feet or more above sea level, the boiling temperature is lowered because air is thinner at higher altitudes. Because of this the amount of time or pressure when canning is affected.
If you are unsure of your altitude you can usually find it by calling your local county or university extension office, the city or county zoning office, or check on your town or city’s webpage. Another option is to search on Google, but please double-check to ensure the information is accurate.
The Ball Blue Book Guide to Preserving has very clear guidelines on time and pressure adjustments that are presented on the following page.
Home Canning Altitude Adjustments for Boiling Water Bath Canners
At 0 to 1,000 feet above sea level, use the stated processing time.
At 1,001 to 3,000 feet above sea level, increase processing time by 5 minutes.
At 3,001 to 6,000 feet above sea level, increase processing time by 10 minutes.
At 6,001 to 8,000 feet above sea level, increase processing time by 15 minutes.
At 8,001 to 10,000 feet above sea level, increase processing time by 20 minutes.
Altitude Chart – Water Bath Canning
Home Canning Altitude Adjustments for Dial-Gauge Pressure Canners and Weighted-Gauge Canners
When home canning using pressure canning, the timings are the same; however, different pressures must be used at higher altitudes.
Here are guidelines for dial-gauge pressure canners:
At up to 2,000 feet above sea level, use 11 pounds of pressure.
At 2,001 to 4,000 feet above sea level, use 12 pounds of pressure.
At 4,001 to 6,000 feet above sea level, use 13 pounds of pressure.
At 6,001 to 8,000 feet above sea level, use 14 pounds of pressure
At 8,001 to 10,000 feet above sea level, use 15 pounds of pressure.
Here are the guidelines for weighted-gauge canners:
At up to 1,000 feet above sea level, use 10 pounds of pressure.
At above 1,000 feet above sea level, use 15 pounds of pressure.
Altitude Chart – Pressure Canning
Using these charts to adjust your recipes becomes like second nature. Here are a few examples to help you understand it in application.
How Altitude Affects a Boiling Water Bath Example:
I am making jam and it calls for a 10-minute processing time in the boiling water bath but I live at an elevation of 1200 feet above sea level. I will add 5 minutes to my processing time and after I bring the water to a rolling boil I will set my timer for 15 minutes.
How Altitude Affects a Pressure Canner Example:
I am processing meat and the recipe calls for 90 minutes of processing at 10 pounds of pressure. I live at 1200 feet above sea level and I have a dial gauge on my pressure canner so I will wait until the dial shows a pressure of 11 pounds of pressure and then start my 90-minute timer.
In the beginning, it can be confusing to understand how altitude affects food preservation, but eventually, it gets easier. If you have any questions please let us know.