DaQatz said:
Normally tomatoes by themselves are acid enough to just hot water bath can. The vinegar is added because you can't guarantee the other veggies in your salsa will be preserved by the tomatoes acid.
The Hot Pepper's questions are relevant, especially the cooked bit. If it's cooked, and the PH is below 4, then yes it should be safe.
Coup said:
Thanks for the tips, ya'll. They are fresh tomatoes so I imagine they should be acidic enough (though store-bought, so who can really tell). I'll find out next week if I get botulism or not when I test it out!
Tomatoes USED TO BE acidic enough to home can using a HWB/BWB (boiling water bath). But commercial tomato growers have been breeding the acidity out of tomatoes for generations. Most commercial tomatoes no longer have enough natural acidity to be safely processed with a BWB. Some heirloom tomatoes may have enough acidity, I don't know the specifics on that.
Current processing methods on the canning websites and Extension service websites no longer suggest just a BWB. They recommend adding some vinegar, lemon, or citric acid to the jars of tomatoes, or doing a full on pressure canning.
The other question regarding pH readings is....when the sauce is newly made, the saucy part may have more acidity from the vinegar/lime juice/whatever, but as was mentioned above, the veggies do not have that acidity. Testing just the juice will not give an accurate pH reading of the whole sauce. If a small portion of the sauce is completely blended to as smooth a sauce as possible and left to blend for a couple days, a fairly accurate pH reading could be had.
Think of it like making pickles. The cukes are stuck in a jar and covered with vinegar brine. If the pickle flesh is tested for pH a day or 2 after being stuck in the jar, the cucumber flesh will still show a very high pH as the vinegar hasn't penetrated the flesh of the cuke and the whole jar has not come to an equilibrium.
2 weeks later...the vinegar will have penetrated the cucumber flesh and lowered the pH of the cuke, making it pickled and safe.
The vinegar/acids in the chunky salsa will eventually penetrate the flesh of the veggies but it will take some time to achieve that equilibrium. Blendering the snot out of a small bit of the salsa will help speed up that equilibrium process.
Another option is to pressure can the sauce. Anything can be pressure canned and be safely stored in the pantry.
