Learn the correct way to sterilize jars so your home-canned goods and jam stay safe and shelf-stable. This straightforward, reliable method removes contaminants and prepares jars and lids for preserving.
What You Need
Gather these basic items before you begin to make the process efficient and safe.
- Glass canning jars (inspect for chips or cracks)
- Large pot or boiling-water canner with a lid
- Jar lifter, heat-resistant tongs, or long-handled utensils
- Clean dish towels or a clean rack for drying
How to Properly Sterilize Jars for Preserving
Sterilizing jars in boiling water is simple and effective. Plan on about 15 minutes of boiling time plus a short cooling period.
- Clean first: Wash jars in hot, soapy water and rinse thoroughly. You may also run them through the dishwasher on a hot cycle. Remove any labels or adhesive residue before washing.
- Submerge jars: Place jars upright in a deep pot or canner. Add enough hot water to cover the jars by at least one inch.
- Boil: Put the lid on the pot and bring the water to a full rolling boil. Once boiling, continue to boil the jars for 15 minutes to ensure sterilization. If you are at higher altitudes, increase the time according to altitude guidelines.
- Keep hot until use: Turn off the heat and leave the jars in the hot water until you are ready to fill them. They can remain in the hot water for up to an hour without losing sterility.
- Remove and dry: Using a jar lifter or heat-resistant tongs, remove jars one at a time and invert them briefly on a freshly laundered towel or a clean drying rack. Fill jars while still hot to prevent thermal shock and to help create a proper seal.
How to Sterilize Lids for Preserving
Lids and sealing bands need attention too. Follow these steps so seals form correctly and remain safe.
- Boil lids: Place flat lids in gently boiling water for 5 minutes. Do not boil rubber seals or sealing compounds aggressively; use a gentle boil as directed by the manufacturer.
- Keep them warm: Leave lids in hot water until you are ready to use them. Use clean tongs to remove lids from the water just before placing them on filled jars.
Tip: Sterilized jars and lids are only safe if handled in a clean environment. Use freshly washed towels or a clean surface to avoid recontamination. Avoid touching the inside of lids or the rim of jars with your hands.
Additional Uses for Sterilizing
This boiling-water sterilization method is also appropriate for other heat-resistant items such as baby bottles, pacifiers, breast pump parts, and certain heat-safe toys. Always check manufacturer recommendations before sterilizing items that include plastic or rubber components.