There are a few basic ways to sterilise jars, here is an easy way to do it for making chutneys, jams, preserves, and more.
Why Sterilise? This removes any bacteria in the jars, which could make the contents of your jars rancid or have spoilage.
Materials:
Roasting tin or baking tray
Glass jars/containers (for canning, making jams, preserves, etc.)
Paper towels, or cloths
Wax circular discs – (Optional)
Step 1. Preheat oven to 140ºC – 160ºC (300ºF – 325ºF)
Step 2. Wash glass jars, and lids in hot soapy water. *If you are using glass jars or containers with rubber seals or rubber rings, then remove them before washing the jars. Use a saucepan filled with boiling water and place the rubber ring pieces inside to sterilise for 15 minutes, then place them on a paper towel or cloth to dry completely.
Step 3. Immediately turn each cleaned wet jar upside down onto the prepared roasting tin or baking tray. Place in the oven for 15 minutes.
Step 4. Remove the jars from the oven. Carefully, transfer your hot jam/preserves into the jars, one by one, leaving about 2 cm (1 inch) of room from the top of the jar.
Step 5. You can tap the jars on the surface firmly to allow the contents to settle and release any air bubbles. Place the lid on the jars, securing each jar. Allow jars to cool slightly before placing lid closures, and dry rubber seals on. Securely close. These sterilised jars should keep for up to six months, depending on what you’ve prepared in the jars. Check your recipe, most will keep a shelf-life from four to six months.
Notes: If you are sterilising your glass jars at the same time you are making your recipe, keep the glass jars in the oven so that they are still hot and ready to be filled when ready.
Always make certain to insert your hot jams/preserves/chutneys into the hot jars, never a cold jar.
*Safety precaution: Never add cold contents to any hot jars, nor add hot contents to cold jars! The glass will shatter!