Sterilizing Jars for Home Canning: What is the Scoop?

With Sharon Peterson

Sterilizing jars is not needed when you’re water bath canning, as long as processing time is more than 10 minutes. Most recipes call for at least 10 minutes processing time or more.

When it comes to preparing jars for canning, you should understand that processing for more than 10 minutes sterilizes both the food and the jars.

Sterilizing jars isn’t necessary for pressure canning either. Everything will be well sterilized by the high heat involved in pressure processing.

Information on Sterilizing Jars & Preparing Jars for Canning: From the National Center for Home Food Preservation.

Jar Cleaning

Before every use, wash empty jars in hot water with detergent and rinse well by hand, or wash in a dishwasher. Unrinsed detergents may cause unnatural flavors and colors. These washing methods do not sterilize jars. Scale or hard-water films on jars are easily removed by soaking jars several hours in a solution containing 1 cup of vinegar (5 percent acidity) per gallon of water.

Sterilization of Empty Jars

All jams, jellies, and pickled products processed less than 10 minutes should be filled into sterile empty jars. To sterilize empty jars, put them right side up on the rack in a boiling-water canner. Fill the canner and jars with hot (not boiling) water to 1 inch above the tops of the jars.

Boil 10 minutes at altitudes of less than 1,000 ft. At higher elevations, boil 1 additional minute for each additional 1,000 ft elevation. Remove and drain hot sterilized jars one at a time. Save the hot water for processing filled jars. Fill jars with food, add lids, and tighten screw bands.

Jars for Canning

Empty jars used for vegetables, meats, and fruits to be processed in a pressure canner need not be presterilized. It is also unnecessary to presterilize jars for fruits, tomatoes, and pickled or fermented foods that will be processed 10 minutes or longer in a boiling-water canner.

Source: From the National Center for Home Food Preservation.

You must, however, always start with clean jars. Always wash your jars before you do any type of canning. I am assuming you would know that all equipment needs to be clean before any canning.

I don’t personally use any recipes that call for less than 10 minutes. I am at high altitude and everything has time added, so I always simply start with clean jars instead of sterilizing jars.

“Can I Sterilize Jars in the Oven, Dishwasher, or Microwave?”

While you may be able to clean canning jars in the dishwasher, it doesn’t sterilize them. If you’re using a recipe that requires jars to be sterilized first, they cannot be sterilized using the oven, dishwasher, or microwave. Use the instructions on this page to ensure your jars are safe.

If by sterilizing you mean processing the filled jars (i.e., canning), then no. That is not the same at all and is never recommended. I talk more about some unsafe canning methods on this page.

How to Sterilize Canning Jars

Go ahead and check your recipe before sterilizing jars. Does it call for less than 10 minutes processing time? Don’t forget to figure you altitude. If so, you should be sterilizing first.

Or if you’ve been sterilizing your jars and you are just more comfortable doing so, don’t stop. It certainly won’t hurt anything. Go ahead and sterilize the jars and have peace of mind.

Here’s how to sterilize canning jars:

Place empty jars right side up on the rack in a boiling-water canner.
Fill the canner and jars with hot (not boiling) water to one inch above the tops of the jars.
Bring to a boil and boil 10 minutes.
Carefully remove hot, sterilized jars one at a time and drain.
They will be hot!
Leave the hot water left in your canner for processing filled jars.

Continue with your canning recipe.

Always Follow Complete Canning Instructions…

When it comes to home canning jars, keep in mind that your jars DO need to be clean and hot prior to filling them with hot ingredients and placing them in a hot canner. Here are instructions for water bath canning and pressure canning.