What Foods Can You Water-Bath Can?
Learn which foods are safe for water-bath canning, why acidity is the key factor, and which low-acid foods must always be pressure canned.
The short answer: water-bath canning is safe for high-acid foods only, those with a pH of 4.6 or below. That covers most fruits, jams and jellies, pickles, properly acidified tomatoes, and chutneys. If the food you're thinking of doesn't fall into one of those groups, it belongs in a pressure canner, not a water-bath pot. Getting this distinction right isn't just about following rules; it's what keeps botulism spores out of your pantry.
Why Acidity Is the Whole Ballgame
Clostridium botulinum is the bacterium behind botulism, and it's a sneaky one. In an airless, low-acid environment, exactly what a sealed mason jar provides, the spores can germinate and produce a toxin that you cannot smell, see, or taste. Boiling water reaches 212°F (100°C) at sea level, which destroys the active bacteria and most spoilage organisms. What it cannot do is reach the higher temperatures needed to kill heat-resistant botulinum spores.
Here is where acidity saves the day. Below pH 4.6, those spores simply cannot germinate and produce toxin. So when a food is naturally acidic enough, or has been acidified by a tested recipe, a boiling-water bath is sufficient to make it shelf-stable and safe. Foods that sit above pH 4.6 must be processed in a pressure canner, which pushes temperatures up to 240°F (116°C) and does destroy the spores.
One critical point beginners sometimes get wrong: boiling longer does not make a low-acid food safe. No amount of extra time in a water-bath pot compensates for insufficient acidity. The only two paths to a safe, shelf-stable low-acid product are proper acidification (using a tested recipe that adds enough acid) or pressure canning. There is no shortcut.
Foods That Are Safe to Water-Bath Can
Naturally High-Acid Fruits and Fruit Products
Most fresh fruits are naturally acidic enough for water-bath canning. Berries of all kinds, cherries, peaches, plums, apricots, nectarines, pears, and apples all fall comfortably below pH 4.6. Grapes, citrus fruits, and tropical fruits like pineapple and mango are also in safe territory. Fruit juices and nectars made from these fruits carry the same acidity.
Jams, jellies, fruit butters, conserves, marmalades, and preserves made from high-acid fruit are among the most popular water-bath canning projects for good reason: they're genuinely safe, they work beautifully in a boiling-water bath, and a single afternoon can stock a pantry shelf for the whole winter.
Pickles and Relishes
Pickling relies on vinegar, acetic acid, to drop the pH of vegetables that are otherwise too low in acid to water-bath can on their own. Cucumbers become dill or bread-and-butter pickles. Zucchini, green beans, beets, and peppers can all become pickles when submerged in a properly acidified brine and processed according to a tested recipe.
Relishes, corn relish, sweet pickle relish, green tomato relish, work the same way. The vinegar does the safety work; the tested recipe tells you exactly how much to use and how long to process. This is why using a tested recipe matters so much: if you reduce the vinegar to suit your taste, you may unknowingly raise the pH into unsafe territory.
Properly Acidified Tomatoes and Salsas
Tomatoes are one of the trickier topics in home canning. Modern tomato varieties range widely in pH, and some fall above the 4.6 cutoff. For that reason, tested recipes always call for added acid, typically bottled lemon juice or citric acid powder (not fresh lemon juice, whose acidity varies). When that acid is added in the amounts a tested recipe specifies, the finished product is safe for water-bath canning.
The same logic applies to salsa. A tested salsa recipe balances tomatoes, peppers, onions, and vinegar or lemon juice in proportions calculated to keep the whole mixture below pH 4.6. You can swap one variety of pepper for another or adjust the garlic, but you cannot reduce the vinegar or lemon juice without potentially pushing the pH into unsafe territory.
For the full picture on why this matters and how to do it correctly, see How to Can Tomatoes Safely and Why You Add Acid.
Chutneys
Chutneys sit at an interesting intersection: they often include low-acid vegetables like onions and peppers, but they're cooked down with vinegar, sugar, and acidic fruit (apple, mango, rhubarb) until the entire mixture is acidic enough to be safe. Again, the key is using a tested recipe, one where someone has actually measured the finished pH, not just assumed the vinegar would be enough.
Quick-Reference: Water-Bath Safe vs. Pressure-Can Only
| Category | Examples | Method |
|---|---|---|
| High-acid fruits | Berries, peaches, apples, cherries, pears, citrus | Water bath |
| Fruit juices and nectars | Apple juice, grape juice, peach nectar | Water bath |
| Jams, jellies, preserves | Strawberry jam, grape jelly, peach preserves | Water bath |
| Fruit butters | Apple butter, pear butter | Water bath |
| Pickles (vinegar brine) | Dill pickles, bread-and-butter, pickled beets | Water bath |
| Relishes | Sweet pickle relish, corn relish, green tomato relish | Water bath |
| Acidified tomato products | Crushed tomatoes with lemon juice, tested salsas | Water bath |
| Chutneys | Apple chutney, mango chutney | Water bath |
| Plain vegetables | Green beans, corn, carrots, peas | Pressure can only |
| Meats, poultry, seafood | Chicken, beef, tuna, salmon | Pressure can only |
| Soups and stews | Vegetable soup, chili, chicken broth | Pressure can only |
| Plain tomatoes (no added acid) | Whole or diced tomatoes without lemon juice | Pressure can only |
| Beans and legumes | Dried beans, lentils | Pressure can only |
What You Cannot Water-Bath Can
Plain vegetables are the classic example. Green beans are perhaps the most common source of home-canning illness in the United States, almost always because someone processed them in a water-bath canner instead of a pressure canner. Corn, carrots, beets (plain, not pickled), peas, squash, and asparagus are all in the same boat. They're low-acid, and no amount of boiling time in an open-water bath makes them safe.
Meats and seafood, chicken, beef, pork, tuna, salmon, must be pressure canned. Full stop. So must soups, stews, and broths. Even if a soup contains tomatoes or another acidic ingredient, the overall mixture is almost certainly above pH 4.6 once you account for everything in the pot.
Plain tomatoes without added acid are also off-limits for water-bath canning, even though many older recipes (including some from decades past) skipped the acid step. Current guidance from the USDA and the National Center for Home Food Preservation (NCHFP) is clear: always add bottled lemon juice or citric acid to tomatoes before water-bath processing.
Picking the Right Recipe
A tested recipe is one that has been developed and verified by food scientists, organizations like the USDA, the NCHFP, or the Ball Blue Book, who have measured actual pH and confirmed that the processing time is sufficient for the jar size and altitude being used. These aren't just guidelines; they're the result of lab work you can rely on.
That word "tested" matters because it rules out heirloom recipes passed down through families, internet recipes without a credible source, and recipes you've adapted by swapping ingredients or changing proportions. Even small changes, less vinegar, more low-acid vegetables, a different tomato variety, can push a recipe out of the safe zone.
For a complete walkthrough of the canning process itself, including how to fill jars and time your processing, see How to Water-Bath Can: A Step-by-Step Guide for Beginners.
Also keep in mind that altitude affects processing time. At higher elevations, water boils at a lower temperature, which means jars need more time in the bath to reach equivalent heat exposure. If you live above 1,000 feet, check the altitude adjustment tables provided by the USDA or NCHFP for every recipe you make. More on that at How to Adjust Canning for Your Altitude.
FAQ
Can I just boil a jar of green beans longer to make it safe?
No. This is one of the most persistent and dangerous misconceptions in home canning. Longer boiling time in a water-bath pot cannot compensate for low acidity. Botulinum spores survive at 212°F regardless of how long they're exposed to it. The only safe options for green beans are pressure canning (which reaches the temperatures needed to destroy the spores) or pickling them in a tested, vinegar-based brine (which drops the pH low enough to prevent spore germination).
Are all tomatoes acidic enough to water-bath can?
Not reliably. Modern tomato varieties vary significantly in pH, and some fall above the 4.6 threshold. That's why every current tested recipe for canning tomatoes includes added bottled lemon juice or citric acid. Use the amount specified in the recipe, it's not optional, and fresh lemon juice is not an acceptable substitute because its acidity is inconsistent.
Can I add low-acid vegetables to my jam or jelly?
No. Adding low-acid ingredients to an otherwise high-acid product changes the overall pH of the mixture, potentially pushing it above 4.6. This is why you should only use tested recipes and not improvise by adding extra ingredients. If you want a product that includes both fruit and vegetables, a chutney or a fruit salsa, for example, find a tested recipe specifically developed for that combination.
What makes vinegar safe for pickling, and can I use any vinegar?
Vinegar works as a preservative because it contains acetic acid, which lowers the pH of the food it contacts. For home canning, tested recipes call for vinegar with at least 5% acidity, the standard commercial strength sold in grocery stores. Do not use homemade vinegar or any vinegar without a labeled acidity, since you cannot verify its strength. Cider vinegar and white distilled vinegar at 5% acidity are both safe choices; the recipe will specify which works best for flavor.
How do I know if a recipe I found online is tested?
Look for attribution to a recognized food safety authority: the USDA Complete Guide to Home Canning, the National Center for Home Food Preservation (nchfp.uga.edu), or the Ball Blue Book. If a recipe doesn't cite one of those sources, treat it with skepticism. Recipes on general food blogs, in older cookbooks predating modern safety guidelines, or passed down through families may not reflect current standards, even if they've been used "for years without a problem." When in doubt, cross-reference against a tested source before proceeding.