Canning and drying are the two most reliable ways to preserve a harvest at home
Canning uses heat and sealed jars to stop bacterial growth, letting you store everything from tomatoes to jam for a year or more. Drying removes the water that bacteria and mold need to grow, and works best for herbs, fruits, and some vegetables. Both methods are safe when you follow the steps exactly — the risk comes from skipping steps or guessing at temperatures and times.
The choice between them depends on what you grew and how you want to use it. Tomatoes, pickles, and jams go into jars. Herbs, apple slices, and hot peppers dry well. Some things work both ways. You do not need expensive equipment — a large pot, jars, and either an oven or a sunny windowsill will get you started.
Key Takeaways
- Canning requires boiling jars at a specific temperature for a specific time based on what you are preserving, and the USDA has tested recipes for safety.
- Drying works by removing moisture and can happen in an oven, a dehydrator, or outdoors, depending on the food and your climate.
- Low-acid foods like beans and corn need a pressure canner (not a water bath) to reach the temperature that kills botulism spores.
- Dried foods last longest when stored in airtight containers in a cool, dark place, and you can tell they are done when they bend without breaking.
- Both methods fail if you skip steps or use untested recipes, so start with USDA or National Center for Home Food Preservation instructions.
Water bath canning for high-acid foods
A water bath canner is a large pot of boiling water that heats sealed jars from the outside. It works only for foods acidic enough that bacteria cannot survive in them — tomatoes, pickles, jams, jellies, and fruit preserves. The acid (from vinegar, lemon juice, or the food itself) is what stops growth; the heat just speeds up the process and helps the seal form.
The steps are: prepare your jars and lids by washing them in hot soapy water, fill them with your prepared food leaving the headspace the recipe specifies (usually half an inch), wipe the rim clean, place the lid on top, screw the band finger-tight (not hard), then lower the jars into boiling water. The water must cover the jars by at least an inch. Boil for the time your recipe says — this varies by food and jar size, usually between 10 and 20 minutes. Remove the jars and let them cool on the counter. You will hear a pop as each one seals; if a jar does not seal within 24 hours, refrigerate it and use it first.
The National Center for Home Food Preservation and the USDA have tested recipes and posted the exact times and temperatures for common foods. Do not use recipes from blogs or old cookbooks unless they match these sources — the timing has changed as equipment and understanding have improved.
Pressure canning for low-acid foods
Low-acid foods like beans, corn, carrots, and meat cannot be safely canned in a water bath because they do not kill Clostridium botulinum, the bacterium that causes botulism. A pressure canner heats the jars to 240°F (116°C), which does kill the spores. A pressure canner is a sealed pot with a gauge that lets you control the pressure inside; it is not the same as a pressure cooker, though some models work as both.
The process is similar to water bath canning — prepare jars, fill them, wipe rims, seal — but the canning time is longer and the pressure setting depends on your altitude and what you are canning. At sea level, most foods process at 10 or 11 pounds of pressure. Higher altitudes require higher pressure. Again, use only tested recipes from the USDA or National Center for Home Food Preservation, and follow the time and pressure exactly.
Pressure canners cost more than water bath canners and take longer to heat and cool, but they are the only safe way to preserve low-acid foods at home. If you grow a lot of beans or vegetables, the investment pays for itself quickly.
Drying food in an oven or dehydrator
Drying removes water until bacteria and mold cannot grow. You can use a conventional oven, a dedicated food dehydrator, or the sun and air. The oven method is slowest and uses more energy; a dehydrator gives you more control and works faster; sun-drying is free but depends on your climate and requires protection from insects.
For oven drying, slice your food into uniform pieces (thinner pieces dry faster), arrange them on a baking sheet lined with parchment paper, and set the oven to its lowest temperature — usually 140°F to 170°F (60°C to 77°C). Prop the door open slightly with a wooden spoon to let moisture escape. Drying times vary wildly: herbs take 2 to 4 hours, apple slices 6 to 12 hours, tomatoes 8 to 24 hours. Food is done when it bends without breaking and has no visible moisture.
A food dehydrator does the same work more efficiently. You stack trays, set the temperature (usually 130°F to 160°F / 54°C to 71°C depending on the food), and let it run. Most dehydrators come with instructions for common foods and drying times. The upfront cost is higher, but if you dry food regularly, the energy savings and speed add up.
Sun and air drying for herbs and peppers
Herbs and hot peppers dry well outdoors in warm, dry weather. Bundle herbs loosely with twine and hang them upside down in a warm, airy place out of direct sun — a garage, shed, or kitchen corner works. They are done in 1 to 3 weeks when they crumble easily. Hot peppers can be strung on a thread and hung in a window or outside in the sun; they dry in 2 to 4 weeks depending on size and humidity.
This method is free and requires no equipment, but it only works if your climate is dry and warm. High humidity or cool temperatures invite mold. If you live somewhere humid, an oven or dehydrator is safer. Once dried, store herbs and peppers in airtight containers away from light and heat — a glass jar in a cupboard is ideal.
Storing canned and dried foods correctly
Canned goods last longest in a cool, dark place — a basement, pantry, or cupboard. Heat and light break down the food and fade the color. Most canned foods stay safe to eat for a year or two, though quality declines after that. Check jars before opening: if the seal is broken, the food looks moldy, or it smells off, throw it out. A sealed jar that looks fine is almost certainly safe.
Dried foods need airtight containers to keep moisture out. Glass jars with tight lids work well; so do freezer bags with the air pressed out. Store them in a cool, dark place — the pantry or a cupboard, not above the stove. Dried foods last 6 months to a year, sometimes longer if stored very dry and cool. Label everything with the contents and date so you know what you have and when to use it.
Common mistakes that make food unsafe
The biggest mistake is using an untested recipe or skipping steps. Botulism is rare but serious, and it comes from canning low-acid foods without enough heat. If you are not sure whether something is safe to can, do not guess — look it up in the USDA guide or call your local extension office.
For drying, the main risk is incomplete drying. Food that still has moisture inside can grow mold in storage. If you are unsure whether something is dry enough, it probably is not — err on the side of longer drying. Herbs should crumble, fruits should bend without breaking, and vegetables should be brittle.
Another common problem is storing canned or dried food in the wrong place. Heat, light, and humidity all shorten shelf life and can cause spoilage. A cool, dark, dry cupboard beats a warm kitchen counter or a damp basement every time.
Frequently Asked Questions
Can I reuse canning jars and lids?
Jars can be reused many times if they have no cracks or chips. Lids cannot be reused — the seal compound wears out after one use. Bands (the metal rings) can be reused. Buy new lids each time you can, and save the jars and bands.
What if my jar does not seal?
If a jar does not seal within 24 hours, refrigerate it and use the food within a few days, or reprocess it with a new lid. Do not store an unsealed jar at room temperature — the food inside is not preserved.
How do I know if dried food has gone bad?
Throw it out if it smells off, looks moldy, or feels damp. If it looks and smells fine, it is almost certainly safe. Dried food does not spoil the way fresh food does — it just loses flavor and texture over time.
Can I can foods that are not in the USDA guide?
No. If there is no tested recipe for something, you cannot safely can it at home. The USDA guide covers the most common foods; if yours is not there, dry it instead or freeze it.
Do I need special equipment to get your free guide?
For water bath canning, you need a large pot, jars, lids, and bands — most of which you probably have. A jar lifter (a tool that grips jars) costs a few dollars and makes the work safer. For pressure canning or drying, you will need to buy a canner or dehydrator, but they are not expensive and last for years.