Canning tomatoes has been traditionally considered safe using the water bath canning method. However, acidity levels have changed and are now very close to the safety borderline of acidity. The standard recommendation is to add acidity to tomatoes to make them safe.
There is much debate about this recommendation. Just remember there are no canning police. There is no one to come and ensure you are using the latest methods. YOU are responsible for YOUR health and the health of your family.
Give tomato products a dose of bottled lemon juice. 1T per pint/ 2T per quart. This will raise the acid level and make it safe for a boiling water bath. No questions, no doubts. ove peace of mind.
note- ALL official recommendations I've read suggest using acidification juice when you are waterbath canning tomatoes. So, if using a waterbath, I also suggest that you use lemon juice.
I have seen differing recommendations from
different extension websites regarding canning tomatoes in a pressure canner. Some
extension websites recommend lemon juice even when pressure canning.... some don't.
I called my extension here in Colorado to verify what I read. (see quote below) The person I talked with confirmed that lemon juice is often recommended for all canning by some extensions. However the Colorado State website states that if you are using a pressure canner acidification is not needed.
I included quotes from both sources a bit down on this page plus links to the websites so you can check it out.
I used to leave out lemon juice when I used a pressure canner. However, lemon juice or other acidification certainly won't hurt anything, plus it adds an extra level of protection. I've never tasted a difference. Thus I've decided to go ahead and add the acidification recommended by most extensions. You have to decide for yourself.
Please if you don't agree or understand this recommendation contact
office. They should be willing to discuss it
with you. I can
only report what is recommended.
You need to make you own decision as to whether you want to include the lemon juice in your pressure canner or not.
Remember - If you add vegetables you must always use a pressure canner. Adding acid to these types of recipes won't change that. The added veggies must be pressure canned. Examples would be stewed tomatoes or tomato based vegetable soup, spaghetti sauce.
Here is a question I received in my inbox. It is in regards to pressure canning tomatoes with methods taught by relatives who have been doing things the "old" way for many years. This is always a hard situation. You don't want to offend your well meaning friend or relative... but, I don't suggest you just go along with them either.
I love your site! My mother-in-law, who is 85 has been canning all her life. --- This is the first year ever they have not had a garden. I have been buying fresh produce and taking it to her this summer.
She has taught me how to can tomatoes and green beans in a pressure canner. I have a couple of questions for you.
She has been canning tomatoes in pints for ever, processing at 5lbs for 10 mins, their elevation is about 1400 ft above sea level -
Our home is about 1200 ft above sea level, I have done 21 pts everything is sealed and everything is beautiful. - the question is: are they safe? should i reprocess them? most were done this weekend. Maybe I am just reading too many opinions, we have been eating them this way for years.
Thanks so much for your time - GREAT SITE!!!!
~ Bobby, VA
Thanks so much for you positive comments on my site. You made my day!
As far as your MIL canning procedures. Five pounds is not enough pressure, and 10 minutes is not long enough. New testing has changed what is recommended. Tomatoes need to be pressure canned for longer than your MIL suggests. Here are full directions. Canning Tomatoes
You said you have been eating them that way for years with no problems... so I can understand wondering what all the fuss is about.
This is one of those personal decisions. I can only suggest sticking with the current recommendations. You may have seen this already but, I wrote about unsafe or outdated canning methods. You could also check with your local extension service.
Again I want to thank you for your excitement over my site. I have enjoyed building it and am glad some are finding it useful. You are a sweetie for bringing your MIL fresh produce. I'll bet she misses having a garden and appreciates your thoughtfulness too.