I decided to make salsa with the tomatoes and peppers from my community garden plot.  I originally planned to can it and store it in the cabinet with my other canned items made over the past few months.  But then I started to research canning safety and had a little freak out. I read that canning tomatoes, with lemon juice, provides sufficient acidity to prevent botulism.  But if you add low acid foods such as onions and peppers, it is important to follow a trusted recipe and use the exact proportions indicated.

Well! I wracked my brain trying to remember if I actually was true to the measurements called for in the recipe. Visions of botulism spores floated around in my mind as I tried to remember, was it a 1/4 cup peppers that I used? More? Less???? Aackk. I gave up and decided to stick the jars in the freezer. Problem solved. Next time I resolved to carefully follow the recipe. Either that, or stop worrying so much.

For the safety conscious, here is a primer on canning salsa:

Make salsa the safe way

By Carol Ann Burtness, University of Minnesota Extension

ST. PAUL, Minn. (9/9/2009) — Bushels of tomatoes are turned into salsa every year. In the U.S., salsa is now more popular than ketchup. To make sure home-canned salsa is safe, it’s important to follow research-tested recipes.

Most salsas combine low-acid foods such as peppers and onions with higher-acid foods such as tomatoes or fruit. To make sure toxic microorganisms do not have an opportunity to grow in the sauce, maintain proper acidity.

Tomatoes used to be considered an acid food, but some of today’s varieties are actually low-acid. To safely can tomatoes or tomato products such as salsa, add acid. Add 2 tablespoons of bottled lemon juice, or a 1/2 teaspoon citric acid per quart of tomatoes or salsa. For pints, use 1 tablespoon of bottled lemon juice or 1/4 teaspoon citric acid. Fresh lemon and lime juice varies in acidity and isn’t reliably safe for canning.

If you do not have bottled lemon juice or citric acid, substitute vinegar (4 tablespoons of 5 percent vinegar per quart). However, vinegar may cause an unwelcome or undesirable taste. If the acid flavor is overwhelming, add a small amount of sugar.

For successful salsa, follow these tips:

• Choose only disease-free, firm produce for canning.
• Tomato varieties and colors can mixed and matched for salsa but still need added acid to make sure the product will be safe.
• Do not reduce the amount of lemon juice or tomatoes in the recipe.
• Do not add extra peppers, onion or garlic. You can reduce the amount of peppers, onion, or garlic.
• Canned chilies may be used in place of fresh.
• You can substitute one type of pepper for another but do not increase the total amount.
• Red and yellow onions can be substituted for each other.
• Spices and herbs may be adjusted to personal taste and will not affect safety. For a stronger cilantro flavor, add fresh cilantro to the salsa just before serving because the hot processing temperatures may reduce the flavor.
• Do not thicken salsas with cornstarch, flour or other thickeners before canning. Add thickeners after opening the salsa if desired.
• Always store open jars of home-canned salsa in the refrigerator.
• If you are using a non-tested recipe or adding additional ingredients, it’s a good idea to either freeze your salsa or store it up to one week in the refrigerator and eat it fresh.