If you’re a huge fan of homemade pickles and jams, then you probably have more mason jars than you know what to do with. These are highly versatile containers that are used mainly for preserving food, but they also work as fancy drinkware. The only question is, are mason jars safe to wash in a dishwasher?
Mason jars are absolutely dishwasher safe. 8-ounce mason jars go on the top dishrack, while 16 and 32-ounce jars go on the bottom dishrack. However, their plastic or metal lids should be washed by hand since dishwashing detergent may wear them down over time.
In this guide, I’ll explain the proper steps of dishwashing a mason jar, how it compares to boiling it in water, and how to wash the plastic or metal lids safely.
What Is a Mason Jar?
A mason jar, which also goes by the name canning jar or fruit jar, is a glass jar with a threaded neck. Mason jars come in a variety of sizes, but the most popular sizes are 8 ounces, 16 ounces, 24 ounces, and 32 ounces. However, if you’re a huge fan of canning foods, then you might be more interested in picking up a humungous 64-ounce or even a 128-ounce mason jar!
What makes mason jars so unique is their two-part lids. Underneath the lid is a rubber gasket that creates an airtight seal, which is a vital part in the pickling process. While the lids can technically be used only once to seal the jar, the rubber gasket, as well as the glass jar, can be used time and time again.
A Scottish farmer by the name of John Landis Mason came up with the design for a glass container with a metal screw-on lid and patented the idea in 1858. What made them so special was their transparent container, which allowed users to see what was happening on the inside. It would become a critical part of preserving winter harvests, but they became a sensation during World War II when non-combatant citizens were encouraged to plant their own crops.
Nowadays, mason jars have become somewhat of a fashionable drinking glass. Even non-picklers might have an entire cabinet filled with mason jars, which is definitely the case for many trendy cafés and restaurants.
Are Mason Jars Dishwasher Safe?
A mason jar is comprised of three main components: the glass jar, the metal or plastic lid, and the rubber gasket. All three are made of materials that are technically dishwasher safe, but that doesn’t mean you should wash them in the dishwasher.
However, the main part of a mason jar—the glass jar—is absolutely safe to wash in a dishwasher. It can be treated like any piece of glass drinkware. The main problem with dishwashing a mason jar is centered around the lid assembly.
The metal or plastic lid, as well as the rubber gasket, should stay out of the dishwasher whenever possible. Ideally, you should wash the lid assembly by hand with regular dish soap and cool running water. That way, you run less of a risk of causing the lid assembly to deteriorate over multiple aggressive washes.
How to Wash a Mason Jar in a Dishwasher
Washing a mason jar in a dishwasher is relatively straightforward. If you’ve ever loaded a dishwasher before per the manual’s instructions, you really don’t need to give two thoughts about where to place the mason jar.
For those who have no idea, the following guide is for you.
Step 1—Briefly rinse the mason jar in the sink. The goal is to get rid of the largest bits of solid debris inside the mason jar. It’s fine if there’s some jam smearing on the inside of the mason jar since modern dishwashers measure how much water to use based on the dirtiness levels of your dishes.
Step 2—Load small mason jars on the top dishrack and large mason jars on the bottom dishrack. The top dishrack is reserved for smaller items, such as glasses and saucer plates. 8-ounce mason jars and smaller should be mounted upside down on the top dishrack. Large mason jars (12 ounces and larger) should go be placed upside down on the bottom dishrack alongside plates, bowls, and cookware.
Step 3—Run the dishwasher on any setting you like. While a heavy wash cycle is ideal for getting rid of large bits of debris from inside the mason jar, you can choose any setting you like. Just make sure to add enough detergent and rinse aid (optional but highly recommended) to get your mason jars sparkling clean.
How to Wash Mason Jar Lids
It’s fine if you want to wash a mason jar’s lid assembly inside a dishwasher, but I’d recommend against doing that. Instead, you should wash the lid by hand in the sink.
Before you begin, remove the rubber gasket from the lid. There might be old food particles trapped between the gasket and the lid, which would be nearly impossible to remove by hand or even a dishwasher. Separating the two gives you access to the debris, making it easier to remove when soaking and washing the lid assembly by hand.
Use regular dish soap to wash the rubber gasket and the plastic or metal lid, rinse them under running cold water, and place them on dishrack to air-dry.
Dishwasher vs. Boiling a Mason Jar
Mason jars should be sterilized before being used for pickling or storing food items for the long term. Sterilizing mason jars reduces the risk of pathogens taking over and causing the contents to spoil. The only question is, can you sterilize a mason jar in the dishwasher?
Yes, you can. All you have to do is mount the mason jar in the dishwasher (per the instructions I’ve provided above) and run a wash cycle that uses the hottest water temperature possible. After the wash cycle is done, use sterilized tongs to handle the mason jar.
However, for the best results, you should place mason jars in a pot of boiling water for at least 10 minutes. Dishwashers can only reach a maximum temperature of around 170°F, whereas water boils at 212°F, giving it a better chance of destroying pesky germs.