If you live above 1000 feet elevation you need to figure your
altitude adjustments.
As
your altitude goes above 1000 feet above sea level the atmospheric
pressure is reduced. This causes water to boil at
temperatures
lower than 212 degrees Fahrenheit.
For safety in water
bath canning you must bring the contents of your jar to at least 212
degrees Fahrenheit. To compensate for the temperature
difference
you must increase processing time.
The pressure canner is
also affected by atmospheric pressures. A pressure canner
must
reach a temperature of 240 degrees Fahrenheit in order to
stop
botulism. To compensate for altitude differences, you must
increase the amount of pressure used. The time does not
change,
only the pressure used.
Time and pressure information given in recipes is
for elevations of 1000 feet or less.
Finding your elevation
What if you don't know your
elevation? You
would think with all the technology out there that there should be a
site where you could plug in your address and find out your elevation.
I have looked for one and just can't find any that are easy
to
use.
One option is to google "your town, your state, altitude".
In
my case the first result was a wikipedia article that included the
elevation of my town.
Another good option is to call your county extension agency
and
they may have some information for you.
Cooperative
Extension System Offices has a general listing of extension
services by state here in the US. If
there is no office listed for your town. Just find the next
closest one.
Be aware of altitude changes if
you live in mountainous areas. In my case again, we live
outside
of town and are actually several hundred feet above the altitude of the
closest
town.
Adjustments
Pressure
canners need an added ½ pound pressure for each 1,000 feet
above sea level.
| Adjustment for
Pressure Canner |
| Altitude in Feet |
Dial Guage Canner |
Weighted Guage Canner |
| 0-1000 |
10 |
10 |
| 1001-2000 |
11 |
15 |
| 2001-4000 |
12 |
15 |
| 4001-6000 |
13 |
15 |
| 6001-8000 |
14 |
15 |
| 8000-10,000 |
15 |
15 |
Water bath canning requires 2 minutes more
time for each 1,000
feet above
seal level.
| Altitude
Adjustments for Boiling
Water Bath Canner |
| Altitude in Feet |
Increase processing time |
| 1001-3000 |
5 minutes |
| 3001-6000 |
10 minutes |
| 6001-8000 |
15 minutes |
| 8001-10,000 |
20 minutes |
Use these charts to make adjustments to
Return from
Altitude Adjustments to Canning Safety
