It’s not always easy to know how to sterilize canning jars. But, the process of sterilizing empty jars is really simple. There are several different methods that we’ll cover.
Each has its advantages and disadvantages. Choose the one that makes sense for you.
Home canning is a proven method of home food preservation and one of the most common for homesteaders. From pressure canning to water bath canning, knowing how to can foods is a valuable skill to have.
Not only can you preserve your harvest, but you can also take advantage of seasonal sales on produce, and preserve them. Food that is properly canned has a shelf life of 12-18 months.
While that’s not as good as freeze drying, it sure is better than letting food go bad after a couple of weeks.
An important step in canning is sterilizing canning jars. The sterilization process ensures that any hidden bacteria have been killed.
Before sterilizing, wash jars in hot soapy water. Jars that have been left in storage for several months usually have become dusty.
Why Do You Need To Sterilize Jars Before Canning?
The purpose of sterilizing canning jars is to destroy any microorganisms present on the jar’s surface. These microorganisms can cause spoilage of the food you are preserving and can also cause illness.
Most people sterilize their glass jars because it’s the best way to ensure that no harmful microorganisms will contaminate their food.
Sterilizing the jars with high heat helps to ensure that the food inside retains its quality and doesn’t spoil. Sterilization of jars also helps to prevent botulism, a potentially deadly form of food poisoning.
How To Sterilize Jars For Canning
Sterilizing jars is important for safety, but also to get a proper seal on your canned goods.
A lot of canning recipes require hot food to be ladled into hot jars. In that case, sterilize your jars just before you use them.
New jars that will be pressure canned, don’t need to be sterilized.
The pressure canning process will bring the temperature high enough that it is not necessary. However, if you are using your new jars for hot-packed canning goods, go ahead and sterilize them.
Sterilization requires additional time to heat up, but the process for heating jars is the same.
This is the Pressure Canner that I Use.
Here are four ways in which you can sterilize these jars right at home.
Sterilize Jars in Boiling Water
The easiest way to sterilize canning jars is to use a boiling water bath. This method is also the recommended method for preserving fruits, jams, and jellies.
- To sterilize your jars using a boiling water bath, simply fill a large pot (you can even use your water bath canner) with enough water to cover the jars by 1-2 inches.
- Place the jars in the pot and bring the water to a rolling boil.
- Boil the jars for 10 minutes, then remove them from the water using canning tongs or a jar lifter.
How To Sterilize Jars for Canning in the Oven
Another method of sterilizing old or new jars is to heat them up in the oven.
If you don’t want to deal with boiling water, the oven works great as well. It does take longer, so it’s a great method if you are able to do a dozen jars at a time.
- To sterilize your jars in the oven, preheat the oven to 225 degrees Fahrenheit.
- Place the clean jars on a baking sheet and place them in the oven.
- Bake the jars for 20 minutes, then remove them from the oven onto a clean towel and let them cool.
How To Sterilize Jars in Microwave
You can also sterilize your jars in the microwave. This is a quick and easy method, but can be a problem with some microwaves, due to low power.
I almost fried my microwave using this method, so use caution. If your microwave overheats, use a different method. Only sterilize 2-3 jars at a time.
I was trying 5 jars at a time, and the microwave got too hot. Don’t sterilize the screw bands or canning lids in the microwave. Microwaves and metal don’t mix.
- To sterilize your jars in the microwave, simply place the clean cold jars in the microwave.
- Heat them on high for 2 minutes. Be very careful removing jars from the microwave. Use oven mitts to remove them, as they will be hot.
- Place on a dry towel to cool.

How to Sterilize Canning Jars in Dishwasher
Another easy way to sterilize canning jars is in the dishwasher. This is a great option if you’re short on time or don’t want to deal with boiling water.
Sterilizing canning jars in the dishwasher is an easy way to sterilize a large number of jars at a time (Looking at you, pasta sauce).
- To sterilize your jars in the dishwasher, put the clean jars on the top rack of the dishwasher and run it on the hottest setting.
- The jars will be sterilized when the cycle is finished.
This method probably takes the longest, but it’s also the least amount of work. If you have the foresight to sterilize your jars before you need them, use the dishwasher.
When canning foods, always sterilize metal lids in boiling water.
Place lids in a bowl, and pour boiling water over them. Let them sit for 5-10 minutes. This helps to ensure a good seal.
What Happens if You Don’t Sterilize Canning Jars?
If you don’t sterilize your canning jars before using them, you run the risk of contaminating the food inside. This can lead to spoilage and potentially illness.
Additionally, jars that have not been properly sterilized are more likely to break during the canning process.
It’s always best to err on the side of caution and sterilize your jars before using them.
This will help to ensure that your food is safe to eat and that the jars don’t break. I’ve had jars break on me while canning. It’s always such a disappointment to have to throw away that food.
FAQs for Sterilizing Jars for Canning
What is the fastest way to sanitize Mason jars?
The quickest way to sanitize Mason jars is in the microwave. Simply place the clean jars in the microwave and heat them on high for 2 minutes. Let the jars cool before using them.
Can you sterilize canning jars without boiling?
Yes, you can sterilize canning jars without boiling them. You can sterilize jars in the oven, microwave, or dishwasher. Simply follow the instructions for each method carefully to ensure that your jars are properly sterilized.
In the canning world, there are a lot of contradictions on what are the right way of doing things. Food safety is very important, but don’t let fear hold you back.
Canning has been done for generations. The canning knowledge that I have has been passed down for generations. My mom taught me, the methods that her mom taught her.
I’ve also learned a lot of canning techniques from my mother-in-law.
Sterilizing your canning jars is an important step in the canning process.
This article has outlined four different ways that you can sterilize your jars right at home. Whether you’re using a boiling water bath, the oven, the microwave, or the dishwasher, make sure to follow the instructions carefully to ensure that your food is safe to eat.

Learning how to sterilize canning jars can save you a lot of trouble in the long run.
Plus, like anything else in this world, there is always more than one way to do something.
Find out what works best for you and go with that! Once you’ve decided which way you prefer to sterilize canning jars, you can start using that method in your own home.