Pressure can tomatos without added acid?

[oeb]

I've read several sites that indicate no acid must be added to tomatos when properly using a pressure canner however only one such site so far is pointedly clear about it. On the other hand, several sites say to add acid when using both water bath and pressure methods. Most people don't add acid to pressure can green beans do they? Ok, then, why add it when pressure canning tomatos? As I recall, my Mom never added acid of any sort to anything but she always used the pressure canner instead of a big open pot. I'm thinking additional acid is never needed and maybe the instructions to add acid are a holdover from long ago when all tomatos where canned with the water bath approach. Has anybody reading this used the pressure method to safely can and then store and much later use tomatos without adding any kind of acid to them?

[Anon001]

I've read that you add lemon juice to canned tomatoes. But, I've seen literally hundreds of jars processed over the years without acid being added and no problems occurring as a result.

I do know that when using a hot water bath canning for tomatoes it is best because many of today's hybrids don't have the high acid content that the old heirloom varieties had.

[CanNerd]

The addition of bottled lemon juice is specifically for tomatoes, whether you 'can' them in a Boiler Water Bath or in a Pressure Canner, to increase the acidity and stability of the tomatoes only. It does not apply to other veggies.

If you look at the recipes in the Ball Blue Book, lemon juice is added in both canning procedures.

[Anon001]

You stated that the acid must be a hold over from long ago. I would disagree. I would think that adding acid to tomatoes for canning is a newer practice, not an older practice.

But, why must lemon juice be added to tomatoes when pressure canning if you don't have to add it to other items? Just curious.

[oeb]

Yup, that's the root of my questions. Is it for taste and/or looks? Adding acid alters the taste in a way I don't need to enjoy the fruit and they've always looked no different to me from those canned without extra acid. Oh well, I'm still very curious about this. Paul, do you can them without acid to no ill effects?
Otis

[NCLee]

My 2-cents..... :)

Adding acid is a fairly new recommendation. Think it was about 10 years ago, or so. I'd have to check my old copies of the BBB to be sure. The reason is that hybrid tomatoes have been bred to reduce the acid content.

As to why add lemon juice to pressure canned, I suspect that the research (expensive) hasen't been done to determine the processing times needed to treat tomatoes as a low acid item. Suspect that just the research to be able to still do them in water bath was done. Thus, the recommendation for lemon juice in pressure canned, just to be sure. (Bring the acidity level up to the same point when the research was done for high acid tomatoes.)

Over the years other low acid foods have had the extensive research done to determine safe processing time tables.

When the change in recommendations was made I just bought a bottle of "lemon juice" and added it to my jars of pressure canned tomatoes, according to the directions. Keep it in the refrigerator. If out of date, or I've used it to make "homemade buttermilk" for biscuit making, I just pick up another bottle, next time I can tomatoes.

Lee

[Anon001]

Otis, I'm odd. LOL I love fresh tomatoes, tomato sauce, tomato juice, etc, but I do NOT like cooked tomatoes. So, I used to plant Romas and this year I switched to Amish Paste for a meaty tomato. I cook them down and can the juice. Then I use the juice to flavor foods such as stews, chili, tomato bread, etc. I can also use the juice to make ketchup.

My mother always canned tomatoes and I know other people around me that do as well, and I've never seen anything added to pressure canned tomatoes. So, like you, I'm curious why it is now recommended. I understand why it has to be added to tomatoes that are canned using a hot water bath, but I'm curious to learn why they recommend it for pressure canning tomatoes.

[oeb]

Paul: ditto

NCLee: I'll bet you're on to something. Sounds logical.

CanNerd: Yes, that's the instructions but directions in some of the old favorite sources are often designed for general purpose application to both methods and so it is just as often not clear whether you absolutely have to add acid with pressure as you must to play it safe with water bath. Could it be a case of unnecessarily playing it safe (which I'm now thinking I might as well do, too).

Now an admission; one of the sources of my curiosity is that town is too far for me to go just for some acid if it isn't needed :-).

Thanks to everyone!

Otis

[NCLee]

Otis, you can use vinegar if you don't have lemon juice.
http://www.clemson.edu/extension/hgic/food/food_safety/preservation/hgic3360.html Scroll down a bit, here.

http://www.extension.umn.edu/distribution/nutrition/DJ1097.html more info on the why and..

Quote: Acidification
To ensure safe acidity in whole, crushed, or juiced tomatoes, add 2 tablespoons of bottled lemon juice or 1/2 teaspoon of citric acid per quart of tomatoes. For pints, use 1 tablespoon bottled lemon juice or 1/4 teaspoon citric acid. Acid can be added directly to the jars before filling with the product. Add sugar to offset acid taste, if desired. Four tablespoons of a 5 percent acidity vinegar per quart may be used instead of lemon juice or citric acid. However, vinegar may cause undesirable flavor changes.

I'd use white, not cider vinegar.

Lee

[CanNerd]

Yup, that's the root of my questions. Is it for taste and/or looks?
Neither. It's for safety and you should not be able to taste the small amount of lemon juice that is added. It is up to you whether you follow suggested safety guidelines or not.

As for ill effects if you don't, it is odorless, colorless and tasteless, but you may not have much warning since it tends to kill.

[sbemt456]

Well here is another 2 cents worth. On our place we raise heirloom variety tomatoes. The new varieties of hybrid tomatoes are made for mass production and they are lower in acid as I understand. If you were canning only hybrid low acid tomatoes you may need to boost the acid content a good bit. When I can tomatoes or any tomato product I never add acid, again 99% of what I can are heirloom tomatoes. The weather will also influence acid content in them, too much water, lower acid. And I never pressure can tomatoes either, just no need if you have high acid. But if you do mix in any other veggie you need to be sure of the canning method for the veggie with the longest processing time and process accordingly.
The older folks didnt have hybrids so the acid was not necessary. This is why all the grannys of old didnt add anything.
And Paul I agree, Amish Paste cant be beat for good thick juice.

Have a great day!

stella

[oeb]

Hi Stella,
As you probably know already I'm trying to convert to nothing but heirloom plants. Next year I hope this will be the case and when I'm there then I'll can those acid filled beauties with nothing added but salt.
Otis