From Garden to Jar
Grandma's pantry shelves full of jewel-colored jars are a beautiful tradition. Here's how to keep that tradition going safely, one tested recipe at a time, in plain words for true beginners.
Canning keeps food on the shelf by heating sealed jars long enough to stop spoilage, then forming a vacuum seal. The catch is that the right method depends on one thing: how acidic the food is.
⚠️ The one rule that matters: acidity
Acid foods (pH 4.6 or lower) can go in a boiling water bath canner. These include fruits, pickles, sauerkraut, jams, jellies and fruit butters, plus tomatoes once acid is added.
Low-acid foods (above pH 4.6) must be pressure canned. That's all fresh vegetables except most tomatoes, plus meats, poultry, seafood and most mixtures. Botulinum spores are very hard to destroy at boiling-water temperatures, so a boiling water bath will not protect you from botulism with these foods (NCHFP, CDC).
Old family recipes are treasures, but use current tested recipes for the actual canning.
New to this? Start with the boiling water bath. Water bath basics, step by step
Equipment you'll need
For a boiling water bath
- A canner or big deep pot with a lid and a rack, deep enough for at least 1 inch of boiling water over the jars (NCHFP)
- Mason-type canning jars with no nicks or cracks on the rim
- Two-piece lids: new flat lids each time; screw bands can be reused
- Jar lifter, wide-mouth funnel, a plastic spatula for bubbles, and a clean damp cloth for the rims
For pressure canning
- A real pressure canner that holds at least four 1-quart jars standing upright on the rack (CDC)
- An accurate gauge. Many county Extension offices will check dial gauges.
- A pressure cooker or Instant Pot is not a pressure canner. That's true even if it has a "canning" button. Cookers heat and cool too fast and can under-process food (CDC, Oregon State Extension).
Garden produce cheat sheet
🫧 Boiling water bath
Acid foods, pH 4.6 or lower, using a tested recipe
- Fruits, jams, jellies and fruit butters
- Pickles and relishes made with a tested vinegar recipe
- Tomatoes, with added acid. Some tomatoes are slightly above pH 4.6, so tested recipes add bottled lemon juice or citric acid to every jar (NCHFP acidification directions).
- Salsa, tested recipes only
♨️ Pressure canner only
Low-acid foods, above pH 4.6
- Green beans, corn, peas, carrots, beets, potatoes, plain peppers
- Most mixed vegetables and soups
- Anything with meat, poultry or seafood
🥒 The dilly bean example
Plain green beans are low-acid and must be pressure canned. But pickled "dilly beans" are made with plenty of vinegar, which makes them acid enough for a boiling water canner. That only works if you follow a tested recipe exactly, like the NCHFP Dilled Beans recipe. Don't cut the vinegar.
⚠️ Safety box
- Use tested recipes only, from NCHFP, the USDA Complete Guide or your Extension office. Follow them exactly, including the processing time, jar size and altitude adjustment.
- When in doubt, throw it out. Never taste food from a jar that is leaking, bulging or swollen, looks cracked or damaged, spurts liquid or foam when opened, or looks moldy or smells bad. Botulism can be deadly, and the food may look and smell normal (CDC).
- Store sealed jars somewhere clean, cool, dark and dry, and never above 95°F (NCHFP).
- If someone may have botulism, get emergency medical care right away.
🐾 Leiyla's Corner
On canning day, Leiyla gets a chew toy in the living room and the kitchen door stays closed. Big pots of boiling water and a curious golden retriever just don't mix. She gets her share of the fun later, supervising the jars as they cool.
📚 Where our canning facts come from
- National Center for Home Food Preservation (University of Georgia), for tested recipes and processing times
- USDA Complete Guide to Home Canning
- CDC: Home-Canned Foods and Botulism
- Your local Cooperative Extension office (find yours through the USDA land-grant university directory). Many county offices will also check pressure canner dial gauges.
Checked October 16, 2026. We never give processing times here. Always use the time in the tested recipe for your food, jar size and altitude.