Bulk Canning Jars

Can I reuse pickling/canning lids and jars?

Yes, you can safely reuse canning jars multiple times, but traditional metal canning lids should only be used once. Glass jars can be reused indefinitely as long as they're free from chips, cracks, or damage along the rim. Inspect jars carefully before each use, as even minor imperfections can prevent proper sealing.

The one-time-use rule for metal lids exists because the sealing compound degrades after heat processing, compromising future seals. However, reusable canning lids with rubber gaskets (like Tattler lids) are available and can be used multiple times when properly maintained.

Metal bands (the screw-on rings) can be reused as long as they're not rusted or warped. After processing, remove these bands for storage to prevent rust and extend their lifespan.

Before reusing any jar, wash thoroughly in hot soapy water and inspect for damage. Never use commercial food jars (like those from store-bought pickles or sauces) for home canning, as they're not designed to withstand processing temperatures and may shatter or fail to seal properly. Always use jars manufactured specifically for home canning to ensure safety and success.

What's the difference between regular jars and canning jars?

Canning jars are specifically engineered for home food preservation, while regular jars—including commercial food containers—are designed only for single-use storage. The key differences involve safety and durability.

Canning jars use tempered glass that withstands repeated thermal shock from boiling water baths and pressure canning. Regular jars, like repurposed pasta sauce or pickle containers, use thinner glass that may shatter under canning temperatures, creating dangerous glass fragments in your food.

The rim design is critical: canning jars feature standardized, smooth sealing surfaces that create airtight seals with two-piece lids. Commercial jars have irregular rim shapes incompatible with standard canning lids, preventing proper sealing and increasing botulism risk.

Wall thickness matters too. Canning jars maintain consistent thickness throughout, ensuring even heat distribution during processing. Commercial containers often have decorative textures or inconsistent walls that create hot spots and cold spots, leading to under-processed food.

While repurposed jars work beautifully for storing dry goods or refrigerated items, only use genuine canning jars for heat-processed preservation. Your family's safety depends on proper equipment designed specifically for the extreme conditions of home canning.

Do I need to sterilize jars before canning?

It depends on your processing time. Jars processed for 10 minutes or longer don't require pre-sterilization—the canning process itself sterilizes them. However, recipes with processing times under 10 minutes need pre-sterilized jars to ensure food safety.

To sterilize, submerge clean jars in boiling water for 10 minutes (add one minute for every 1,000 feet above sea level). Keep them hot until filling to prevent thermal shock. You can also run jars through a complete dishwasher cycle, timing it so they're hot when you're ready to fill them.

Regardless of sterilization requirements, always start with thoroughly washed jars. Wash in hot soapy water or run through the dishwasher, then inspect for chips or cracks that could prevent sealing.

Remember: this guidance applies only to proper canning jars, not repurposed containers. Never use commercial food jars for heat processing, even if sterilized. Only use glass jars with the tempering and standardized rim design necessary for safe canning. While clean repurposed jars work well for cold storage or refrigerated items, they're unsuitable for boiling water bath or pressure canning, regardless of sterilization.

Why didn't my canning / pickling jars seal properly?

Failed seals in canning typically stem from several common issues. First, check your jar rims—even tiny food particles, seeds, or brine residue prevent proper sealing. Always wipe rims with a clean, damp cloth before applying lids.

Old or damaged lids are another culprit. Metal canning lids should only be used once, as the sealing compound deteriorates after heating. Inspect lids for dents, rust, or damage before use.

Incorrect headspace causes sealing problems too. Too much headspace means insufficient vacuum formation; too little causes food to bubble out during processing, contaminating the seal. Follow recipe specifications exactly.

Insufficient processing time or incorrect water levels in your canner can prevent proper vacuum formation. Water must cover jars by at least one inch throughout processing.

Using improper jars is a critical mistake. Commercial food containers lack the precise rim dimensions needed for home canning. Even if they appear to seal initially, they're unreliable and dangerous for shelf-stable storage. Use glass canning jars that have the standardized openings and tempered glass required for safe sealing.

Finally, altitude affects processing—add time for elevations above 1,000 feet.

What size jars should I use for different foods?

Choosing the right jar size affects both processing time and food quality. Half-pint (8 oz) jars work perfectly for jams, jellies, and syrups—ideal portion sizes that get used quickly once opened. These smaller jars are also excellent for gift-giving.

Pint (16 oz) jars suit pickles, salsas, pie fillings, and fruits. They're practical for smaller households and foods consumed within a few days of opening.

Quart (32 oz) jars are best for tomatoes, green beans, large pickle spears, and apple sauce—foods your family will use in larger quantities. They're economical for batch cooking and meal planning.

Remember that jar size directly impacts processing time. Quarts require longer processing than pints of the same food to ensure heat penetrates to the jar's center. Always follow tested recipes that specify both jar size and corresponding processing times.

Specialty sizes exist too: 4-ounce jars for samples and party favors, 24-ounce jars for an in-between option, and half-gallon jars for juices (though these require pressure canning). Stick with glass jars in appropriate sizes for your recipes to ensure safe, successful canning.