How to Reuse a Peanut Butter Jar

Upcycle Your Empty Peanut Butter Jar
If you have kids, chances are you go through lots of peanut butter. Here’s how to reuse a peanut butter jar instead of tossing it.

If you have kids, chances are you go through lots of peanut butter. Here's how to reuse a peanut butter jar instead of tossing it.

I have kids, so I will pretend that that’s why we go through so much peanut butter here in our house.

It’s definitely that, and NOT my propensity to eat a spoonful of peanut butter, dipped in a bag of mini chocolate chips, as a lifesaving snack when I’m tired and cranky.

If you, too, go through plenty of peanut butter in your house, there’s something you should know: that empty peanut butter jar is a miracle of modern upcycling.

It all has to do with the type of plastic that a peanut butter jar is made from. Peanut butter is particular, and when manufacturers wanted to start using plastic instead of glass to store it, they had to figure out a way to keep the peanut butter from going rancid inside the jar. Some plastics don’t provide enough of an oxygen barrier to keep peanut butter tasting fresh, so to solve that problem, your plastic peanut butter jar is made from PET.

DIY Density Discovery BottlesA couple of qualities about PET plastic make it excellent for upcycling (and horrible for landfills). One is that great oxygen barrier. Put something in a peanut butter jar and seal it, and that thing will stay safe from the elements. Peanut butter jars are non-reactive and biologically inert in the face of many substances, so I keep a few around just to use in science experiments and with sensory play. We upcycled peanut butter jars to make our ocean in a bottle jars, and our DIY density discovery bottles.

Second is the terrible fact that PET plastic does not deteriorate. If you put it in a landfill, it will still be there a thousand years from now. That’s tragic and gross, but it also means that an empty peanut butter jar is archival. You can make it into a time capsule. You can use it for altered art.

Just don’t put it in the dishwasher, because it will melt. To prepare a peanut butter jar for crafting, I like to fill it with soapy water, screw the lid on, and let it soak. The next day, it’s much easier to use a bottle brush to scrub out the peanut butter residue. Let the lid and jar air-dry, and then it’s ready to go.

When you no longer need your peanut butter jar, clean it out again and toss it into the recycling, from whence it will be shipped off to be made into something else.

Written by Julie Finn

I'm a writer, crafter, Zombie Preparedness Planner, and homeschooling momma of two kids who will hopefully someday transition into using their genius for good, not the evil machinations and mess-making in which they currently indulge. I'm interested in recycling and nature crafts, food security, STEM education, and the DIY lifestyle, however it's manifested--making myself some underwear out of T-shirts? Done it. Teaching myself guitar? Doing it right now.

Visit my blog Craft Knife for a peek at our very weird handmade homeschool life; my etsy shop Pumpkin+Bear for a truly odd number of rainbow-themed beeswax pretties; and my for links to articles about poverty, educational politics, and this famous cat who lives in my neighborhood.


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  1. We like to reuse PB jars, but I have found that most of the ones we get are not really water tight. I’ve decided they will make the prefect hardware holders for in the garage. I currently use glass jars, but I seem to have a case of the dropsies lately. Plastic PB jars to the rescue!

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