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How to Sterilize Glass Jars: Useful Tips to Remember

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Why should you sterilize glass jars before using them to store your preserves and jams? This is because sterilizing jars is essential to your product’s success and longevity. Sterilizing is an important part of food preservation to eliminate fungi, yeasts, or bacteria. This helps in protecting the food stored in the jar. Jars that are not properly cleaned will contaminate the food, causing it to spoil quickly.

Sterilization is a simple process so there is no reason to omit it in the canning process. In this article, we are going to show you how to clean and sterilize glass jars properly along with important reminders and tips when sterilizing. So keep on reading to know more!

Table of Contents

Things to Note Before Sterilizing Your Glass Jars

Here are important reminders you should take note of before you sterilize glass jars.

Do Not Boil Metal Lids and Their Rubber Rings

Never boil your jar’s metal lids and their rubber sealing rings. Always check the interior of the metal lids and see if they have a ring inside before sanitizing your jars. Although the rubber or plastic will not completely melt, the lid will no longer fit properly onto the jars.

The extreme boiling water’s heat can destroy the lid’s rubber ring which can result in a broken seal. This can lead to contamination of your jar’s contents. Simply submerge the lids and rings into simmering water for ten minutes to clean them thoroughly. You can also use the water you used for sanitizing the glass jars to clean the lids and rings once the water has slightly cooled. You can also check this guide on how to sterilize canning lids.

Empty glass container
Source: Pixabay

Make Sure That Your Sterilizing Area is Clean

Sterilizing glass jars is pointless if your working place is not clean. Even though you have cleaned your jars, they can easily be contaminated with bacteria from the surrounding areas. If you will be setting your glass jars on dish towels for drying, make sure that the dish towels are clean.

If possible, can your preserves immediately after sterilizing your glass jars. If the sterilized jars are left for an hour or more, you should sterilize them again before you can your products. And when you can, do not put hot products into cold jars or cold products into hot jars.

Source: Pinterest

Use Oven Mitts

Sterilizing means subjecting your glass jars under high temperatures so you need to make sure that you handle your jars with care. Use oven mitts too to avoid burning yourself.

Source: Pinterest

Cleaning Your Jar

Before sterilizing your glass jars, make sure to clean them first. You have two options for cleaning your jars: rice soaking and scrubbing.

Rice Soaking

  1. Take ¼ cup of raw and uncooked white rice and then put it inside each jar. We do not recommend using partially-cooked rice.
  2. Add 3 drops of dish soap into each jar.
  3. Fill ¾ of the jars with hot (not boiling) water.
  4. Close the jars and then shake them for 20-30 seconds.
  5. Drain the rice and then rinse the jars. It is recommended to rinse them 2 or 3 times to ensure that no grain will be left inside the jars.
  6. Discard the grains and air dry your jars.
Source: Pinterest

Scrubbing

  1. Get your bottle brush. Use one with soft bristles to prevent the brush from scratching your glass jars’ inside. This also ensures that no areas will be left for microorganisms to grow.
  2. Wet your brush using hot water.
  3. Scrub each jar’s interior. Make sure that you brush all areas by pivoting your bottle brush’s handle. 
  4. Rinse your jars by filling them with hot water. Swish the water around to make sure that all areas of your jar’s interior will be washed. Pour the water out and do another round of rinsing. Pay attention to any particles forming in the water.
  5. If the particles are not going away, add 2 drops of dish soap and 1 teaspoon of salt to the jar. Fill ⅓ of the jar with hot water. Cover it and then shake it for 20 seconds.
  6. Let the jars dry on a strainer. Make sure to store them upside-down.
Source: Pinterest

How to Sterilize Your Glass Jars

Now, let us proceed to the five methods on how to sterilize glass jars.

Using a Microwave

The first method is by using a microwave. This is ideal for regular glass jars but not for jars with metal lids and Kilner-style ones.

  1. All you have to do is clean your jars and then rinse them. Make sure that they are not dry when you put them in your microwave.
  2. Microwave them for 30-45 seconds based on your jars’ size.
Source: Good Housekeeping

Using a Dishwasher

This sterilization method is good if you own a steam dishwasher or if your machine has a setting for high temperature. You can use this method for Kilner-style glass jars and jars with screw tops, rubber rings, and clip tops.

  1. Fill the dishwasher with the cleaned jars.
  2. Run a rinse cycle and make sure that the ending time will match the time when your preserves, pickles, or jams are ready for canning.
  3. Once the rinse cycle is done, take one jar at a time and fill them with the hot preserve/jam.

The dishwasher sterilization method is obviously an easy one, but it uses up plenty of water. Plus, it is hard to time the cycle’s ending with the time when your product is ready for canning.

Sterilizing glass jars using a dishwasher
Source: Good Housekeeping

Using an Oven

This is the most reliable method to ensure that your jars are thoroughly clean before putting your preserves in them. It takes longer though compared to the other methods because the process takes about 30 minutes. The oven method also works well with jars that have rubber rings and clip tops.

  1. Heat your oven to 130°C or 275°F. Do not heat more than the recommended temperature or your glass jars might break.
  2. Lay 2 layers of newspaper on the oven’s shelves but not on its floor. For gas ovens, make sure that the newspapers are not near any flame.
  3. Arrange your glass jars inside the oven and see to it that they do not touch each other.
  4. Sterilize your jars for 20 minutes or more.
  5. Use oven mitts to remove the jars from your oven. Put them on a heating pad or a heatproof mat.
Source: Abenson

Using a Stove

The fourth method is by using a stove if you do not have a microwave, dishwasher, or oven. Below is a short video showing how to sterilize glass jars using a stove:

The actual sterilization process using a stove will approximately take around 25 minutes.

  1. Get a large pot or a boiling water canner.
  2. Place the glass jars in the pot with their top parts facing upward.
  3. Cover your jars completely with hot water (not boiling). Make sure that the water level is one inch higher than the height of your jars in the pot.
  4. Wait for the water to boil.
  5. Start timing when the water boils. Remember the suggested timing based on your location’s altitude.
  6. After the boiling process is completed, turn off your stove. Leave the jars in the pot if you will not start the canning process yet.
  7. Use tongs or jar lifters to remove your jars from the pot.
  8. Drain the jars well and then let them dry.

Recommended Boiling Time Based on Altitude

The standard way of sterilizing glass jars is by submerging them in boiling water. But, your location’s altitude will affect the boiling temperature of the water. If you are in higher altitudes, the boiling point is lower so you need to make adjustments on the time your jars will spend in the boiling water.

Ten minutes is the recommended boiling time at sea level up to 1,000-feet elevation but you have to add 1 more minute in every additional 1,000 feet.

Using Vinegar

Distilled white vinegar can be more effective in killing bacteria compared to sanitizing solutions available commercially.

  1. Fill ⅓ of your glass jar with distilled white vinegar.
  2. Add hot water until the bottle is filled up to the top.
  3. Leave the jar for 10 minutes.
  4. Empty the jars and then rinse them until the odor of the vinegar dissipates which can take 2-3 full rinses using hot water.
  5. Let the jars dry.
Sterilizing glass jars using vinegar
Source: Pinterest

Tips on Sterilizing Glass Jars

  • Leave pickles, preserves, and jams for about 15 minutes before you seal them.
  • Sterilize more glass jars than needed to avoid wasting your time from doing another sterilization process once your product is ready.
  • Remove glass jars from your dishwasher or oven only when you need them or they are going to get cold.
  • Do not use rusty or damaged jar lids because they will not produce a tight seal. You can use cellophane and wax discs instead.
Sterilizing glass jars
Source: Pinterest

Conclusion

Recycling glass jars is a great way of reducing the amount of waste we generate that destroys the environment. By recycling jars, not only are you helping save the earth but it also allows you to reduce your packaging expenses. And if you are looking for a reliable glass jar manufacturer, you can rely on Roetell. We supply a wide variety of food-grade glass containers for different applications.

If you’re looking for more Glass Jars Manufacturers, check out the following articles:

 

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