Preserving food

How to Seal Glass Jars to Preserve Food

Max. D Gray
By Max. D Gray. Updated: October 6, 2017
How to Seal Glass Jars to Preserve Food

Sealing glass jars is very important to prevent food from becoming spoiled. There are many different techniques to preserve food, and one of the most common is vacuum sealing or packaging. There are various ways to carry it out, but most households choose to do it by sealing glass jars.

Reusing glass jars for conservation is a good way to keep the products in perfect condition for a long period of time. However, you need to make sure that you seal glass jars properly to preserve the food and prevent mold. In this oneHOWTO article we'll explain how to seal glass jars to preserve food.

You'll need:

  • Glass jars
  • Food to conserve
  • Large pan
  • Cloth
  • Water
You may also be interested in: How to make tomato sauce to preserve in a jar

Steps to follow:


The first thing you need to do to seal food in glass jars will be to sterilize the canning jars, mason jars or glass containers that you will use. This way, you'll guarantee that the products remain in good condition. You should also sterilize the caps or lids by boiling them in water for approximately 10 minutes.


Once you have sterilized the glass jars, fill them with food you want to store. Ensure that the ingredients do not reach the edge, leave some free space. You can use sealed glass jars to preserve all sorts of foods, from homemade fruit preserves and chutney to fermented foods like pickles or yogurt.


Then, tightly close the lids. If your arms aren't very strong, we recommend asking for help - you don't want to risk any mold! If you want to consider using cloth covers or airlocks, take a look at our article on how to make a fermentation jar for more instructions.


The next step to seal glass jars is to put the filled, closed jars in a pan or pot. Place a cloth at the bottomto prevent them from banging in to each other and breaking. Some people choose to skip this step, but we truly recommend it, especially if you're starting out in the world of preserving food.


Then, fill the pan with water to cover the jars. You can use tap water.


Bring the water in the pan to the boil and leave to cook for about 20 minutes. If the jars are very large or if there are lots of them you may need more time. After that, get the sealed jars out with the help of gloves, tongs or a cloth so as not to burn yourself. Let them cool down.


In order to know if the glass jars have been sealed properly, try pressing down the button or center on the lid; if you can't press it down, it's sealed.

This is how to seal glass jars to preserve food. If you have any tips, please share them in the comments section!


Here are is a recipe idea for a food you can put in a glass jar and preserve: tomato sauce.

If you want to read similar articles to How to Seal Glass Jars to Preserve Food, we recommend you visit our Food & drink category.

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1 comment
When using lumiInarc working glasses with plastic lids to conserve apple butter, how do I sterilize the lids. Thanks
OneHowTo Editor
Plastic is much harder to sterilize at home than glass due to its porous nature. One helpful trick is to microwave them on high (if they are microwave safe) for about 3 minutes. Place a secondary container of water in the microwave with them to prevent damage.
How to Seal Glass Jars to Preserve Food