Canning food at home in jars can be a great way to preserve home-grown fruits and vegetables, or “preserves,” for long winter months. However, using unclean jars can introduce bacteria into the preserves that may spoil the food. Sterilizing the glass jars used in canning has traditionally involved boiling the jars in large pots of water for long periods of time. With the invention of the microwave, sterilizing jars has become simpler and less labor intensive.

Things You'll Need

Wash the jars thoroughly. Make sure there is no food residue left on the insides of the jars. After sterilizing and drying, the jars will need to be filled immediately with the food preserves. If there is any residue left after sterilization it can contaminate and ruin the preserves.

Pre-heat the oven to 280 degrees Fahrenheit or 160 degrees Celsius. The hot oven will be used to dry the jars once they have been sterilized in the microwave.

Fill jars halfway with cold water. Place the jars in the microwave. Depending on the size of the microwave, more than one jar can be sanitized at the same time.

Heat jars in the microwave on high for around three minutes or until the water boils. The boiling water will sanitize the inside of the jar.

Place jars upside-down in the oven. Allow the jars to drain and dry in the oven. Once the jars have dried and are still hot, they will be ready to be filled with preserves and sealed. Heating the jars allows them to expand so they will not break when filled with hot preserves.


  • Remember to sanitize the lids of the jars to keep harmful bacteria out of the preserves.