How to Sterilize Jars in the Microwave

By Michael Belcher

Canning food at home can be a great way to preserve home-grown produce. However, using unclean jars can introduce bacteria into the preserves that may spoil the food. Sterilizing the glass jars used for canning has traditionally involved boiling the jars in large pots of water for long periods of time, but with the invention of the microwave came a much simpler and less labor-intensive method.

mason jar with water isolated on white
credit: thawatpong/iStock/GettyImages
Sanitizing jars in the microwave is quick and easy.

Step 1

Wash the jars thoroughly. Make sure there's 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's any residue left after sterilization it can contaminate and ruin the preserves.

Step 2

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.

Step 3

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.

Step 4

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.

Step 5

Place jars upside-down in the oven. Once the jars have dried and are still hot, they'll be ready to be filled with fruits or veggies and sealed. Heating the jars allows them to expand so that they don't break when filled with hot preserves.