Heat the oven to 180°C- don't be tempted to heat the oven any higher or you may risk the glass breaking. Lay a double layer of newspaper on each oven shelf but not the floor of the oven. Arrange the jars on the shelf making sure the jars are not touching each other. Close the oven door and sterilize the jars for about 20 minutes. Using thick oven mitts, remove each jar from the oven as needed onto a heatproof mat or heat pad, making sure you fill while the jam or preserve is hot as is the jar. Do NOT add cold food to hot jars, or hot food to cold jars.
Method 2 :
Fill your dishwasher with clean cold jars and run a minimum or rinse wash to time the ending with when your jam, preserve or pickle will be ready. Use the jars one at a time from the dishwasher needed making sure you fill while the jam or preserve is hot as is the jar. Do NOT add cold food to hot jars, or hot food to cold jars.
In the Microwave
Clean the jars as normal, rinse but leave the jars a little wet. Microwave for no more than one minute.
Do's and Dont's
- Do NOT add cold food to hot jars, or hot food to cold jars.
- Remove jars from the oven or dishwasher only when needed or they will cool down too much.
- Always sterilize more jars than you think you will need. Should you have more mixture than anticipated it is too late to start sterilizing once the food is ready.