Preserving the Glut Safely

Why it matters

A productive Texas garden buries you in tomatoes, beans, okra and squash all at once. Freezing, canning and drying turn that glut into months of food, but home canning done wrong can produce botulism toxin you cannot see, smell or taste. Follow USDA/NCHFP tested methods exactly and preserving is safe.

Step by step

1. Pick the right method for the food Acid foods (fruit, pickles, jams, and tomatoes with added acid) can go in a boiling-water canner. Low-acid foods (beans, okra, peppers, greens, most vegetables) must be pressure canned or frozen.
2. Use only tested recipes Follow current USDA/NCHFP directions and never change the amounts of vinegar, vegetables or water in a canning recipe.
3. Always acidify canned tomatoes Add 2 tablespoons bottled lemon juice or 1/2 teaspoon citric acid per quart (1 tablespoon or 1/4 teaspoon per pint) to the jar before filling, whether you use a water bath or pressure canner.
4. Run the canner correctly In a water bath, keep at least 1 inch of boiling water over the jars and start timing only once it boils. In a pressure canner, vent steam for 10 minutes before pressurizing, and let it cool down on its own.
5. Adjust for altitude and test your gauge Sea-level times can fail at 1,000 feet or more, so look up your elevation. Have a dial gauge checked every year and replace it if it is more than 2 pounds off.
6. Blanch before freezing vegetables Blanching stops the enzymes that ruin flavor, color and texture. Boil for the listed time, cool quickly, drain, pack with 1/2-inch headspace and freeze.
7. Dry at steady low heat Use a dehydrator with a thermostat, or an oven held at 140 to 150°F checked with a thermometer. Store dried vegetables sealed in a cool, dark, dry place.

Key facts

• Low-acid foods have a pH above 4.6; acid foods are 4.6 or below. Tomatoes and figs can sit just above 4.6, which is why acid must be added.
• Botulinum spores survive boiling-water temperatures; low-acid foods need 240 to 250°F, which a pressure canner reaches at 10 to 15 PSI.
• The same safety in a boiling-water canner would take 7 to 11 hours versus 20 to 100 minutes in a pressure canner.
• Botulinum toxin cannot be seen, smelled or tasted.
• Ohio State Extension advises boiling home-canned low-acid foods for 10 minutes before eating below 1,000 feet, adding 1 minute per extra 1,000 feet.
• Open-kettle canning, oven canning, microwave or dishwasher processing, and 'dry canning' are not recommended.
• USDA withdrew its summer squash canning process; Clemson says do not can plain summer squash or zucchini.
• Freezing does not kill germs; it only slows their growth.
• Properly stored dried vegetables keep about 6 to 12 months (Colorado State).

Texas notes

• Much of East and Coastal Texas is below 1,000 feet, but parts of Central and West Texas are well above it; check your elevation before using sea-level processing times.
• Okra, peppers and greens pile up in Texas summer heat; all are low-acid and must be pressure canned or frozen.
• Do not can tomatoes from dead or frost-killed vines at the end of the fall season.
• Freeze squash instead of canning it.