Canning 101: On Adjusting for Altitude

February 14, 2012(updated on October 3, 2018)

Columbia River Gorge hills

One thing I rarely mention in my recipes is the necessity to adjust cooking and processing times if you live more than 1,000 feet above sea level. I don’t bring it up often because even in my 20th floor apartment, I don’t come close to being that high up (the bulk of Philadelphia is at sea level and the highest portion of the city doesn’t go more than 500 feet above sea level).

Thing is, not all of you live in my lovely city and so elevation is something you do need to keep in mind. The reason it has an impact in canning is that once you get more than 1,000 feet above sea level, the temperature at which water boils gets lower (there’s a calculator here that allows you to plug in your altitude and get your specific boiling point).

If you use a thermometer to monitor the progress of your preserves, you don’t have to do too much to adjust during cooking. Just know that when your jam comes to a boil, it could still be a few degrees shy of 212° and may still have quite a way to go before reaching its set point.

However, elevation has more of an impact on the processing of preserves because once water boils, it can’t get any hotter. This means that even if your canning pot is happily boiling away, it might not be as hot as you think. The way that the USDA and the National Center for Home Food Preservation has you compensate for this temperature differential is by increasing processing time. Here’s the guide for making these adjustments.

1,001 to 3,000 feet, add 5 minutes
3,001 to 6,000 feet, add 10 minutes
6,001 to 8,000 feet, add 15 minutes
8,001 to 10,000 feet, add 20 minutes

If you live above 1,000 feet, you also have to adjust the amount of pressure you apply during pressure canning. The rule of thumb is that you need an additional 1/2 pound of pressure for every 1,000 feet you are above sea level. If you have a weighted gauge canner, you’ll just use the 15 pounds of pressure setting for any recipe that calls for 10.

Sharing is caring!

Posted in

Leave a Reply

Your email address will not be published. Required fields are marked *

53 thoughts on "Canning 101: On Adjusting for Altitude"

  • Thanks for the reminder! If I understand this correctly, does this also mean that the gelling point is different at higher altitudes?

  • I am at 6000 ft. in Arizona. I really don’t have a problem with gelling, unless I am a little too liberal with the recipe! 🙂 You learn to adjust recipes when you live this high. After a while it becomes second nature, and you don’t even think about it anymore. I even have relatives that are at 8000 ft that have no problem with canning.

  • The real point has to do with safety of the final product; the boiling temperature of the hot water bath or pressure cooker.

  • Not sure about gelling. I live at 9200 ft in CO; when I make candies, I have to reduce the temperature called for (300° for brittles becomes 282° for me at my home).
    I haven’t done any pressure canning, but I may next summer. For water bath canning, I have to boil my jars for 35 minutes!

    1. Good thought about the candy — I was curious about that too when my peanut brittle never hardened, but I think that was my error 🙂

      1. I was so angry when my favorite Christmas toffee was no longer sold nearby. I groused for about a week when I finally had my brain engage. I boiled water and used a candy thermometer to see our boiling point (199F) Then when making the candy I subtracted 13 degrees to the regime’s temperatures. With candy I was also able to verify my calculations with the water drop forms. I’m hoping that adding the extra timing will allow me to make my key lime marmalade. Thanks for the information.

  • Interesting article, I’ve been living in the French Alps (for the winter season) and have had to adapt my way of cooking – it’s been a learning curve to say the least, and I hadn’t even thought about boiling temps for canning!

  • I too am in Colorado and canning at 8300′. I would love to find someone that is also canning and water bathing at the additional 20 mins and 15 # pressure. Pickles are mushy, jelly can be runny and will not set….I need some advise with “altitude” Canning at #15 has not been a problem. Do you have any connections? thanks again for all the canning recipes and information I love your site and have past it along to many canning friend! Marilyn

    1. I live in the Springs, and while not quite as high as you are, I haven’t had any issues with set. I just have to boil it a little bit longer and adjust the 220 temp accordingly.

  • Thanks for the lesson! The picture at the beginning of your post looks like it was taken here in Kamloops. I didn’t think there was another place on the face of the earth that looked like that!

  • Thanks for posting this! I’m at 3,440 feet and although I knew I should make a slight adjustment to my processing time, I’ve never seen a handy chart that told me how much longer I should go.

  • I’m so happy to finally see this post! I sent you an email asking about adjusting for altitude a while ago and thought it may have been a good post for your canning 101 blogs. I thought that you didn’t think it was relevant or bother to comment on it. Thanks!

  • We have been canning at 6500+ feet in Colorado for over 20 years. We always add 15 mins to our processing time for hot water bath canning. We’ve made lots of pickles and more different kinds of jams than I can count. The altitude has never been an issue. But thanks for discussing it. Food safety is the #1 concern. No one has ever gotten sick from anything we can and we’ve never had a jar go bad. We want that to continue

  • Help!
    I’m using all different sizes of WECK jars. All my processing times are for mason jars in my recipie books. How do I know how long to process? Weck has so many different sizes not comparable to mason jars. Ahhhhhhhh help!

  • I live in New Hampshire at 940 feet, so a heck of a lot closer to 1,000 feet than sea level. Is there any reason not to go with an extra five minutes?

    By the way, I just started canning last year. The blog is great, as is the book. I just used your dill pickle recipe on a bunch of pickling cucumbers straight from my garden.


  • I live at about 5000 feet, and already make the time adjustment for canning. However the problem I run into is getting my jam to the proscribed temperature. Last night I prepared your kumquat marmalade, and though I boiled it for more than an hour, it had not yet reached the suggested 220˚ (because of our low boiling point). I didn’t want to boil off all of the water, so just stopped it and proceeded. Do you have any suggestion for me? Do you think I should pressure cook my jam to get the pectin to extract ok?

    1. Are your jams and marmalades ending up runny? If you can’t get to the proscribed temperature, it might be time to call in some additional pectin.

  • So what if I didnt know that I had to increase the poundage and only cooked green beans and corn (seperately) at 10 pounds instead of 12? Is my food bad? Or does it just have a shorter shelf life?

    1. If you didn’t process your food at a high enough pressure, it may not be safe. It’s not about it having a shorter shelf life or not. It can be incredibly dangerous if you don’t follow proper procedures.

  • I just canned some chicken and I got the altitude wrong. I canned at 14 pounds pressure when it should have been 11. How will this effect my chicken?

  • I recently made and canned applesauce (first-timer to canning). I forgot about adjusting for altitude. We are at 1400′ and I should have added 5 min. to the boiling time. The jars all sealed (half-pint jars) fine. I’m so sad to waste all the ingredients and work. Will I be able to tell if the jars have gone bad?

    1. If they spoil, they will either mold or begin to ferment. Neither are dangerous forms of spoilage and you’ll easily see or smell it when you approach the jar. Hopefully you won’t experience any kind of spoilage at all!

      1. Thanks for your quick reply! Is botulism a concern? I opened a jar yesterday and it seemed fine but I didn’t know if botulism caused obvious signs of spoilage. I’m going to make your roasted corn salsa from your book soon and I’ll be sure to adjust the times this time!

  • Hello, does this mean that a 5 minute boiling water processing time is sufficient for altitudes below 1,000’? If so, what would be the range in ounces of jars processed? Thank you in advance. And I hope this finds you well.

  • I wasn’t aware of this when I canned 27 jars of pickles at 5200 feet. I processed for 15 minutes as the recipe said, completely unaware of the rules of altitude. So, does that mean all of my pickles are now no good? I did process for longer than 15, but probably not as long as as 25 minutes.

    1. The very worst that can happen is that the jars will lose their seals or start to ferment. Just keep an eye on them.

  • Is it possible to overcook pectin to the point that it breaks down and stops gelling? I live at 9,000′ altitude and I’m really starting to suspect that the extra 20 min of processing time is the cause of the problem I’m having with consistently runny jams and jellies. I’ve tried different recipes, different brands of pectin, multiple thermometers, and all of the “old-fashioned” ways of testing the set before canning. Despite being at the correct temp according to a thermometer AND getting the right results on my spoon and plate tests (and the left over product being perfect consistency in the pot after cooling) I always end up with a runny jam/jelly in my jars after water bath processing that never sets up. I can’t for the life of me figure out what’s happening. Could it be that the pectin has overcooked?

    1. I have heard that it is possible to overcook pectin. I’ve never experienced it personally, but it could be possible.

  • Hi..I just finished canning 48 pints of jalepenos …and as I lay in bed tonight at midnight pondering all my hard work I realized that I forgot to adjust for altitude. I processed my jars for 10 minutes. Are they safe? I live at 3600’. I am so bummed at this huge mistake! Help!

    1. Yikes, what a bummer. However, the good news is that these pickles will probably be okay. The worst that can happen is that you may have a few jars that lose their seals or start to ferment. Nothing truly dangerous can grow in such an acidic environment, so just keep an eye on the jars and discard any that lose their seals or start to fizz.

  • Hi im new to this canning. I just get really confused with the whole alttitude thing an how to determine the correct pressure. I have a 23qt presto pressure canner. I thank u in advance for any help you can give.

    1. You don’t have to adjust for altitude if you’re using a pressure canner. The pressure is the pressure.

  • I am at 5000 feet and am terribly confused regarding the pressure I am expected to use for canning. Everything I have read says 15 psi is the recommended but how do I get there? I cannot get my canner to that point. I turn up the heat and it just releases more steam causing the pressure to remain at 11 psi. I turn down the heat and no help there either. My canner only came with one weight so what is the trick to this? For now I just process 15 minutes more. Am I at risk here?

    1. It sounds like either your canner isn’t sealing properly or that the dial gauge isn’t giving you a true reading. Because if the canner is within its safe zone (and 15 psi is within that), you should be able to reach that level without it venting steam. Do you have a cooperative extension in your area? I’d suggest that you have them test your gauge. Alternatively, reach out to the manufacturer, explain what you’re experiencing, and ask them to help you troubleshoot it.

  • Hi! I’m having pressure canning issues, I really hope you can help! I am not a novice, have been pressure canning for 10 to 12 years. I recently moved from 400 feet to 1660 feet above sea level. I’ve made the adjustment from 10lbs to 15lbs but the results have been terrible. I recently had a 50 percent failure rate with my tomato soup and this is just one incident in a list of others since I moved here. Please, I’ve researched and can figure no reason for this. When I lived in 10lbs land I rarely had an issue!! Please Help!!!!

  • I made raspberry /blackberry jam but forgot to add 10 minutes to the processing time (4200 feet elev). Will the jam be ok?

    1. It should be okay. It just has a slightly higher chance of spoiling because the processing time didn’t impart as much heat as desired.

    1. You only start adjusting for altitude if you live above 1,000 feet. So you don’t need to adjust. If the recipe calls for 10 pounds of pressure, that’s what you should use.

  • I recently bought a 23 quart Denali pressure canner and canned 7-9 pint jars at a time of green beans and then beets. I used a 15 pound pressure gauge with weight and then pressure canned at 11-12 psi for 20 minutes at 5,885 feet. All jars sealed except one. Will we be okay over here or should we throw out? I really don’t want anyone getting sick.

  • My land is at an altitude of 998 feet. I live in a split level house, and my kitchen is on the second level. Should I use 15 lbs? or would 10 be ok?