Can Mason Jars Handle Boiling Water?

Mason jars have long been a staple in kitchens, craft rooms, and DIY workshops across the globe.

One common question that surfaces when utilizing mason jars for various projects is: “Can Mason Jars Handle Boiling Water?”

Whether you’re looking to make homemade jam, create a DIY candle, or perhaps try to sterilize the jars for safe food storage, the question is highly pertinent.

This article aims to delve into the science and safety guidelines concerning mason jars and boiling water, shedding light on best practices and potential risks.

Can Mason Jars Handle Boiling Water?

Yes, according to their official website, Mason jars can handle boiling water

These jars are made from annealed glass (and sometimes tempered glass), which means they can withstand hot temperatures and are suitable for holding hot boiling liquids.

However, there are a few precautions you need to take. 

Ensure the Mason jar is at least at room temperature before you pour boiling water into it, or place it in a pot filled with boiling water. 

This step helps to reduce the risk of thermal shock, which can occur when a mason jar is exposed to sudden, drastic temperature changes.

It’s best to preheat the jar before pouring boiling water into it to minimize the risk of breakage or cracking. 

It’s even better if you let the jar heat up along with the water, instead of putting boiling water straight into a cold jar.

Older or damaged mason jars are more prone to cracking or breaking when exposed to high heat, which can be dangerous. For safety reasons, always choose heat-resistant, high-quality jars.

By taking these precautions and using the right type of mason jar, you can confidently expose mason jars to boiling water.

Also read: Can You Freeze Mason Jars?

What are Mason Jars Made of?

The primary material used in mason jars is glass, often heat-treated for strength and resistance to temperature fluctuations. 

This helps to reduce the risk of cracking or breaking when subjected to boiling water or temperature changes.

Glass is an ideal choice because it is non-reactive and does not corrode when exposed to acidic or salty foods. 

Mason jars are often made from simple soda-lime glass. However, some brands, like Ball Mason Jars, may use tempered glass for increased strength and durability. 

Tempered glass is designed to handle temperature fluctuations better than regular glass, reducing the risk of cracking or breaking when subjected to boiling water or temperature changes.

The lid of a mason jar typically consists of two parts: the metal band and the flat disc with a rubber seal. 

The metal band screws onto the jar’s threaded neck while the flat disc sits on top, sealing the jar’s contents. 

The rubber seal on the underside of the flat disc creates an airtight seal when the band is tightened. 

This seal is vital for preserving food and preventing the growth of harmful bacteria.

Also read: Can Mason Jars Go In The Oven?

Can You Pour Boiling Water into a Mason Jar?

Yes, you can pour boiling water into a mason jar.

However, it is important to take some precautions. This will avoid thermal shock or breakage due to sudden temperature changes.

Remember to : 

  • Make sure the jar is at least at room temperature. It’s even better if you let the jar heat up along with the water.
  • Avoid pouring boiling water directly into a cold jar.
  • Gradually heat the mason jar before pouring hot liquids like coffee or tea.
  • Check the jar for cracks or other damage before using it.
Also read: Are Mason Jars Microwave Safe?

Things to Remember Before Placing Mason Jars in Boiling Water

Here are a few things you need to remember before placing the mason jars in boiling water: 

Clean the Jars 

Wash them with hot, soapy water, and rinse them thoroughly. 

Drying them is not necessary, as they will be preheated in boiling water anyway. 

This helps remove any dirt or bacteria that could compromise your preserved food.

Preheat the Jars

 Do this before placing them into boiling water for processing. This is important to avoid cracking or breaking due to thermal shock. 

You can preheat the jars by submerging them in hot water at 180° F.

Just remember that the jars should be fully immersed, and use a jar lifter to safely remove them from the hot water.

Take Care with the Lid and Band 

While Mason jars are designed to withstand high temperatures, it’s best to avoid placing the lid directly on a jar that’s already immersed in boiling water. 

The sealing compound on the lid can soften when exposed to heat, and if it’s too soft when applied to the jar, it may not create an airtight seal. 

Wash the lids and bands in hot, soapy water, and place them on a clean towel or paper towel to dry before using them.

Ensure there is Enough Water in the Canner

The jars must be fully submerged in boiling water, with at least one inch of water covering the top of the jars. 

This is important for creating the necessary vacuum seal and preventing the jars from being exposed to air during the processing time.

Use a Boiling Water Canner if Possible 

Boiling water canners are specifically designed for safely processing Mason jars. 

They are deep enough to ensure that there is at least one inch of briskly boiling water above the jar tops.

If you don’t have a boiling water canner, you may still be able to use a large pot, but choose one with a flat bottom, tight-fitting lid, and a suitable rack for the jars.

Also read: Wide Mouth vs. Regular Mouth Mason Jars

Can You Double Boil Mason Jars?

Yes, you can double-boil mason jars, but there are some precautions you need to take. 

When using mason jars in boiling water, it is crucial to avoid rapid temperature changes as this can cause the glass to shatter. 

To prevent this from happening, always place the mason jars in cold or room temperature water and then heat the water gradually with the jars inside.

When double boiling, you may want to use a separate container for the hot liquid, such as a glass measuring cup or a smaller jar. 

This way, the heat from the boiling water below will gently distribute around the mason jar, preventing it from getting too hot too quickly. 

You should also be cautious not to overfill the mason jar, as the contents could expand during heating, potentially causing the jar to crack.

How to Place Mason Jars in Boiling Water for Sterilization

Sterilization is a crucial step to ensure your jars are clean and safe for canning or storing food. Here are the easy-to-follow steps that will guide you through the process:

Inspect and Clean the Jars and Lids 

Before you start, examine your mason jars and lids for any cracks, chips, or damages. Next, wash them using warm soapy water.

Make sure you rinse them thoroughly to get rid of any soap residue.

Fill a Large Pot with Water 

Choose a pot big enough to accommodate all your jars, with enough space between them to prevent them from touching each other. 

Fill the pot with water so that it covers the jars by at least an inch.

Submerge the Jars and Lids 

When using a canner, avoid putting the jars directly on the bottom of the canner. 

Doing so can cause uneven heating and may result in damage to your mason jars. 

Instead, use a canning rack, which helps distribute heat more evenly and prevents your jars from breaking.

Place your mason jars and lids on a canning rack and carefully lower them into the pot. 

Ensure that the jars are fully submerged in the water. If you don’t have a canning rack, you can place a towel on the bottom of the pot to prevent the jars from directly touching the pot’s base. 

This will help to avoid any potential breakage due to the heat.

Bring Water to a Boil 

Put the pot on the stove and bring the water to a rolling boil.

Cover the pot with a lid, as this will help to maintain a consistent temperature inside.

Sterilize the Jars 

Once the water is boiling, let the jars and lids sit in the boiling water for 10 minutes.

This will ensure they are properly sterilized and clean, ready for use.

Carefully Remove the Jars 

After sterilizing, turn off the heat and carefully remove the jars and lids using jar lifters or tongs. 

Place them on a clean towel or cooling rack to dry and cool down. Make sure not to touch the insides of the jars or lids, as this could introduce contaminants.

Now, your mason jars are sterilized, and you can confidently use them for canning or any other purpose without worrying about the presence of harmful bacteria or germs.

Watch the video below: 

How to Seal Mason Jars After Sterilization

To do this, fill the jars with your desired contents, leaving about 1/4 inch of headspace at the top. This allows room for the vacuum seal to form as the jar cools.

For example, recipes like fruit jams may require a smaller headspace than pickles or salsa. The standard headspace guidelines are as follows:

  • 1/4 inch for jams, jellies, and preserves
  • 1/2 inch for fruits and tomatoes
  • 1-1.25 inches for pickles, relishes, and other low-acid foods

When filling Mason jars, it’s helpful to use a canning funnel to avoid spillage and ensure the proper headspace.

Remember to use canning jar tongs to safely handle the hot jars during the process.

After filling the jars, wipe the rim with a clean, damp cloth to remove any residue that may interfere with the seal. 

Place the lid on the jar such that the sealing compound on the lid comes into contact with the jar’s rim. 

Screw on the ring until it is tight, but not too tight to allow air to escape during the sealing process.

How to Place Sealed Mason Jars in Boiling Water for Canning

The water bath canning method is recommended by the National Centre for Home Preservation to ensure the jars are adequately heated and sealed to prevent foodborne pathogens.

Follow the procedure below to place sealed jars for canning: 

  • Once the jars are sterilized, carefully remove the jars using a jar lifter and set them on a clean towel to cool. 
  • Do not boil the lids of mason jars, as the rubber sealing bands might perish, which could allow air into the jars and contaminate the contents. Instead, place the flat lids in a saucepan and cover them with water, then bring it just to a simmer over medium heat.
  • Use tongs to remove the lid and seal from hot water, and place them on a clean surface to air dry.
  • Once everything is dry, it’s time to fill your mason jars with the food you want to preserve. 
  • Use a jar funnel and a ladle to fill the jars, leaving the appropriate amount of headspace as per your recipe. Wipe the rim of each jar with a clean, damp cloth to ensure a proper seal.
  • Next, place the sterilized lid on the mouth of the jar and screw on the ring until it’s tight. Be careful not to overtighten, as this could prevent the jar from sealing properly.
  • Place the sealed mason jars on the rack, evenly spaced, and fill the pot with enough water to cover the tops of the jars by at least 1-2 inches. Turn the heat to high and bring the water to a rolling boil. 
  • Once boiling, set a timer for the processing time specified in your recipe. During this time, maintain a steady boil and secure the pot lid.
  • Once the set time is over, wait for five minutes. Use a jar lifter to remove the jars one by one. 
  • Place them on a towel or a cooling rack and leave one inch of space between them. 
  • Leave them as they cool down for 12 or 24 hours undisturbed.
  • Wash off any residues on the outside of jars, label them, and store them away.

Watch the video below 

What Are the Different Foods I Can Can Using the Boiling Method?

The boiling water method is mostly suitable for high-acid foods like fruits, fermented foods containing lactic acid, and vinegar pickles. 

Let’s dive into the different food categories that you can preserve using this method.

Fruits

Fruits have a high acid content, which makes them ideal for the boiling water canning method.

You can preserve fruits like peaches, pears, apples, cherries, and berries. 

The process involves submerging fruit-filled mason jars in boiling water, which then creates a vacuum seal, keeping your fruits fresh and ready to consume later.

Vegetables

While many vegetables have a low acid content and are better preserved using the pressure canning method, there are some exceptions. 

Pickled vegetables like cucumbers, beets, and carrots are great candidates for the boiling method because the added vinegar increases their acidity. 

This process maintains the crunchiness and taste of the vegetables, extending their shelf life.

Fermented Foods

Fermented foods like sauerkraut, kimchi, and pickled okra contain lactic acid, which makes them suitable for canning with the boiling water method. 

By storing these foods in mason jars and using the boiling water method, you can preserve their flavors, textures, and nutrients for a longer duration.

Jams, Jellies, and Spreads

Homemade jams and jellies made from high-acid fruits are perfect for boiling water canning. 

This method retains their taste, color, and consistency, allowing you to enjoy your favorite spreads throughout the year.

Frequently Asked Questions about Boiling Water in Mason Jars

Below are some commonly asked questions people have about putting Mason jars in boiling water.

What Is Inversion Canning?

Inversion canning is a method used to preserve foods by flipping filled and hot-sealed mason jars upside down right after sealing. 

This method is discouraged due to safety concerns, as it may not kill all harmful bacteria in the jars properly.

What Is the Difference Between Canning and Sterilizing Mason Jars?

Canning is the process of preserving foods in mason jars, while sterilizing is the act of cleaning the mason jars to eliminate bacteria before canning. 

To sterilize mason jars properly, you should place them in boiling water for at least 10 minutes.

Can You Put Tea, Coffee, and Soup in a Mason Jar?

Yes, you can put tea, coffee, and soup in mason jars, especially when using heat-resistant jars. 

Always take precautions to avoid thermal shock by allowing your jars to reach room temperature before adding hot liquids.

Why Did My Mason Jar Not Seal After Sterilization?

If your mason jar did not seal after sterilization, it could be due to a faulty lid or a rim that is not properly cleaned. 

Make sure your lids and rims are free of debris and check for any dents or damage before sealing.

Do You Need to Use a Lot of Water While Pressure Canning?

When pressure canning, you must use enough water to create steam and pressure for proper sterilization and cooking. 

In general, you should begin with about 2 to 3 inches of water in your canner when using mason jars.

Will Boiling Water Break a Mason Jar?

Boiling water may break a mason jar if it’s exposed to sudden temperature changes or if it has existing damages like cracks or chips. 

Always inspect your mason jars and preheat them to minimize the risk of breakage.

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I’m Jueria and I am a regular contributor on cookeryspace.com. In my articles, I share time-saving techniques, appliance wizardry, and health-friendly recipes to bring taste and wellness to your table. So raise a glass (or a spatula) with me, to good health and good food, made easy!