We have already made 14 pints of red salsa & are now looking at using our green tomatoes in salsa verde. I was reading a recipe on line which said you cannot use fresh lemon or lime juice for canning. That's all we used in our red version. (1/2 cup per 7 pints) I'd hate to think we'd have to throw this out! If there's a risk, can I open them, recook it and freeze it?
It is recommended to only use research based recipes for salsa when canning. Not sure what your recipe includes but 1/2 cup lemon juice per 7 pints sounds low considering that most research based salsa recipes for canning include peppers, onions, etc which are low acid foods. I would suggest that you open your jars and boil them for 10 minutes and then freeze them. Do not taste since botulism toxin might be present.
Most research based recipes call for bottled lemon or lime juice. The reason is that the pH (acidity) of the bottled juice is consistent. It can vary with fresh lemons and limes. There are a few research based salsa recipes in the Ball Complete Canning book that use fresh lemon juice but they say that they are tested for fresh. I would recommend you download Salsa Recipes for Canning from the Extension catalog. You can substitute green tomatoes and tomatillos for red tomatoes in any of the recipes. The tomatillo recipe is very tasty.