Creating airtight containers is incredibly cheap and easy and will help your food last for much longer. I've had avocados in these jars stay green for weeks! I often use them to do a big salad prep on Sunday, and then have jars for lunches throughout the week.

This Instructable might not be fancy or have a ton of steps, but it has honestly been the most life-changing hack when it comes to my food preparation, and I hope others will find it as useful as I have!

Supplies

Mason Jar
Thumbtack
Electrical Tape
Ziploc Air Pump (under $10 and available at places like Amazon and Bed, Bath, and Beyond)
Scissors

Step 1: Prick the Mason Jar Top

Using your thumbtack, create a small opening in the lid of the Mason Jar (or equivalent).

Step 2: Fill Up Your Jar

Add the food that you want to keep fresh, whether it is guacamole, herbs, vegetables, etc.

Step 3: Seal the Jar

Place a sliver of electric tape over the hole. I have found the best results come from making this sliver as small as possible. I would cut at where my finger is in the above picture, so that the sliver is half the width of the tape.

Step 4: Suck Out the Air

Using the Ziploc pump, seal the air from the container but pulling on the lever. When you press on the lid, it should not move at all.

Step 5: Enjoy Your Airtight Containers!

Store everything in your heart's desire in these containers, and enjoy long-lasting food. The video shows a very satisfying whoosh when the jar is opened.