Please note the Tala Glass Jars can be sterilized in the oven for making preserves etc.Oven method: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. Heat the oven to 350°F/180°C/Gas 4 - don't be tempted to heat the oven any higher. The glass should heat with the oven. DO NOT place the glass jars in a hot oven, the glass needs to heat with the oven.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.Easy Method: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.Made in EnglandMicrowave Method:Clean the jars as normal, rinse but leave the jars a little wet. Microwave for no more than one minute.