How to make an airtight cookie jar

There’s nothing better than cookies fresh out of the oven. The warm, rich smell makes people flock to the kitchen.

What’s even better than freshly baked cookies, though, is a stash of cookies that lives on your kitchen counter and is at your fingertips whenever you want it.

However, sometimes those stored cookies get hard or go bad quickly because they are not stored properly in an airtight container. Without proper storage, those delicious cookies can become hard and crumbly.

So how do you make a cookie jar airtight? The best way to make an airtight cookie jar is to place the cookies in a Ziplock bag and then put them in an airtight jar with a silicone or rubber lid. If the jar you bought doesn’t have a seal, you can make one with a self-adhesive rubber strip or moldable glue.

Read on to learn why airtight cookie jars are so important for fresh cookies, best practices for storing your cookies, how to make an airtight cookie jar, as well as which cookie jars on the market are the best.

Why is an airtight cookie jar important?

Having the right container to store your cookies ensures that soft cookies stay chewy and crunchy ones stay crunchy. This means having an airtight container to prevent any external forces.

The number one reason cookies go bad is moisture in the jar. Too much moisture can make those (supposedly) hard cookies mushy and moldy, while moisture can also make those chewy cookies rock hard.

Airtight cookie jars are the best way to combat this moisture. Not only that, having the cookies in their own airtight container allows the temperature and humidity inside the jar to remain unaffected.

Since moisture is the biggest enemy in the cookie jar game, glass or metal containers are your best bet, as they help control humidity.

It’s best to stay away from plastic or ceramic cookie jars, as they don’t combat moisture as well as glass or metal.

How to make a cookie jar airtight

Although you can buy some cookie jars that are advertised as airtight, you might be surprised at how poorly the cookies keep.

Or maybe you have a mint condition jar that just needs some TLC and you want to use it to store your cookies. Fortunately, there are a few ways to ensure that your cookie jar is truly airtight and can preserve the integrity of your cookies.

The first step to ensure airtightness is to put the cookies in a closed plastic bag. Make sure you get all the air out and close it completely. Next, insert this sealed bag into the cookie jar.

To make sure your cookie jar is equipped to store cookies properly, you can add 1 of 2 things to the lid: a self-adhesive rubber seal, also known as a gum strip, or a moldable glue.

self-adhesive rubber strip

Self-adhesive strips, or weather stripping, are strips of rubber or foam that stick to a surface on their own. To make sure your cookie jar is truly airtight, you should steer clear of the foam and use a rubber seal.

The process of adding the rubber strip to your cookie jar lid is quite simple.  First, make sure the lid is clean of any dust or debris and completely dry.

Next, peel the backing of the rubber strip to reveal the adhesive and slowly add it to your cap making sure it adheres well before finishing the entire cap. 

That’s it! You now have an airtight cookie jar. To ensure the highest quality, be sure to store your cookies in a ziplock before transferring them to your new cookie jar.

moldable glue

Another option for making your own airtight cookie container is to use molding glue.

Using moldable glue is a little trickier than using self-adhesive strips and takes a little more time, but it’s still a great option that usually lasts a little longer without needing to be replaced.

To get started, you want to make sure the cookie jar lid is clean and completely dry.

The glue is extremely malleable and comes in what looks like a hot sauce packet, so you want to make sure you get it in a good straight line before trying to add it to the lid. 

Fortunately, moldable glue has the ability to form into any shape for up to 30 minutes , so you don’t have to work too fast when using it.

Once you have a good line, add the glue to the inside of the cookie jar lid. Make sure it fits well and that it’s not too thick or too thin.

Once the glue is well set on the lid, take the lid and close the cookie jar so that the moldable glue sits nicely between the lid and the jar.

Let it dry for at least 12 hours, but up to 24, before separating the lid and jar.

Material

It’s not just the tight lid on a cookie jar that affects the cookies, but the material of the jar itself as well.

The best materials for cookie jars are metal or glass, as they hold moisture the best. 

Ceramic and plastic cookie jars tend to allow moisture to collect inside, so stay away from these materials if possible.

Tips for Storing Cookies

Although having an airtight container is the most important thing when it comes to storing cookies, there are a few other tips that will help ensure that your cookies remain as tasty as possible:

Let them cool down completely

Before storing the cookies in a container, it is very important to allow them to cool completely.

As we’ve mentioned, moisture is the enemy of cookies and if there’s heat on the cookies when you store them, condensation will build up and ruin the texture of your cookies.

They should be at room temperature before you put them in a container.

Store them in a temperature controlled area

The area in which you store the jar can also affect your cookies.

You want to make sure to keep the airtight cookie jar in a cool, dark place or somewhere where the temperature won’t fluctuate constantly. 

The kitchen counter is fine as long as the jar is out of the sun, but the pantry is also a good place.

Store the different types of cookies separately

You should make sure to store the different types of cookies separately.

This will not only help prevent the flavors from mixing and melting, but it will also keep the texture of your cookies intact.

Putting soft cookies in with crunchy cookies will cause each one to quickly lose its desired texture.

Layer the cookies

Although this can be a bit tedious in a mason jar, layering the cookies between pieces of parchment paper also helps them maintain their texture and flavor. 

From the looks of it, you probably don’t want to do this with a glass jar, but with a metal or ceramic jar that you can’t see inside, this extra step can help preserve the cookies a bit longer.

Bread

There’s a weird trick that helps keep your chewy cookies extra chewy: put a slice of bread in the ziplock bag with them before popping them into the jar.

The cookies absorb moisture from the slice of bread, keeping them soft and chewy for days after they’ve been baked.

How long do cookies last in an airtight container?

Although there are many factors that influence this, such as the types of cookies, the place where they are stored and the airtightness of the container, the average duration of the cookies is 3 days.

Now, 3 days is the period for them to be exactly like the first day they came out of the oven.

After 3 days the texture and flavor begin to diminish, but they are edible out of an airtight container for up to 5 days.

The best airtight containers you can buy

For the ultimate glass container, the Klikel Glass Mason Jar is an excellent airtight option.

It comes with 2 jars, its airtightness is guaranteed, so you don’t need to make your own airtight jar, and it is made of glass, so the possibility of condensation is low. 

Plus, it has a nice look that makes it a great addition to your countertops.

If you want a metal cookie jar, choose the Outshine White Vintage Farmhouse Cookie Jar.

This metal cookie jar promises to be airtight so you don’t need to buy any other materials, it’s big and can hold a lot of cookies, and the metal helps maintain the integrity of the cookies. 

Also, the cookie jar is quite cute and charming with the word “Cookies” on the front and would look great in any kitchen.

Related questions

Now that we’ve gone over how to make your cookie containers airtight, let’s take a look at some related questions!

How do you store cookies in the freezer?

The best way to store cookies in the freezer is in a ziplock freezer bag or an airtight glass container. 

Just like when storing them on the counter or in the pantry, it is important that whichever way you choose to store them in the freezer, they are completely closed.

How long do cookies last in the freezer?

Cookies can last up to 6 months in the freezer.

Be sure to date the packaging before putting them in the freezer to prevent them from being eaten after their expiration date.

What is the best way to reheat a frozen cookie?

The best way to reheat a frozen cookie is in the oven. Preheat the oven to 350°F and place the frozen cookies on the cookie sheet. Cook for about 5-7 minutes or until the cookie is hot.