Let’s face it – if you drink coffee and have a Keurig machine you can only make so many seed starters, necklaces, Christmas ornaments, lamp shades, mobiles, wreaths and craft organizers with your K-Cups before you start throwing them out again. Plus it’s dangerous to cut the top off every one with a sharp knife. It’s just a matter of time before you slice open a finger!
And anyways you can do so much more with the coffee grounds if you like plants, and I’m a gardener so I definitely like plants! Coffee makes the ideal natural compost for just about anything organic.
Add coffee grounds to your house plants by working the used grounds into the first ½ inch of your potting soil and the grounds will help retain moisture as they break down and feed your plants.
Dump the coffee grounds into your flower gardens or vegetable garden and the grounds will help loosen up the soil.
Want to try growing mushrooms? Used coffee grounds are the ideal medium – GOOGLE mushroom coffee grounds.
If you fish you can raise your own bait with an earth worm bed, and yes they love used coffee grounds!
And you don’t think there’s enough coffee in K-Cups to mess with? 100 K-Cups typically contain over 2-1/2 pounds of coffee grounds and 100 K-cups a month is only about 3.3 cups of coffee a day. At the rate I drink coffee I easily consume 60 pounds or more a year! That’s a lot of organic material for my garden.
With this many K-Cups, I think the ideal solution is to come up with a quick and efficient way to empty used K-cups. And it needs to be something that does not involve using a sharp knife. It took a little bit of 3D modeling and some trial and error but I came up with my 3D printed K-Cup Recycle Shell I call the K-Cup Blaster.
What about the waste plastic? My town feeds its garbage into an incinerator and the waste heat is turned into electricity.
In addition to this shell you will need:
A short piece of 2” Dowel – Home Depot sells a 4’ long 2” dowel for less than $9.00
A cheap rubber Mallet – I bought one at Home Depot for $4.97 plus tax.
A Ball Mason Jar with a screw on lid ring – I had one of these laying around.
And of course – plenty of used K-Cups!
Step 1: 3D Print or Purchase the K-Cup Recycle Shell
For those with a 3D printer I've made my 3D file available for free at:
Note: I had mine printed in nylon and I do not know how well this model will work printed in PLA or ABS plastic!
If you don't own or have access to a 3D printer, you can buy our K-Cup Recycle Shell printed in strong and flexible nylon directly from Shapeways for $32.95:
Shapeways Printed K-Cup Recycle Shell
Step 2: Cut Your 2" Dowel
You need to cut off about a 2.6" length of 2" dowel. Unfortunately I could only find these in 48" lengths but at least it's cheap - less than $9.00 at Home Depot.
You'll also need a ball mason jar, lid ring and a rubber mallet. I do not recommend a regular nail hammer because you'll be banging on top of glass! I bought a cheap rubber mallet for $4.97 plus tax from Home Depot.
Step 3: Assembly
Assembly is easy. When I did the 3D design I sized the plastic to fit inside the lip of the jar and inside the lid ring.
You just sit the lip of the K-Cup Blaster inside the lip of the jar then screw down the lid ring.
And it's important to use the lid ring. It keeps the K-Cup Blaster lip securely fastened to the mason jar.
Step 4: Usage
Usage is pretty straight foreword.
- Assemble the parts.
- Place the mason jar on a towel.
- Drop your K-Cup into the K-Cup Blaster, lid side down.
- Drop in the wooden dowel.
- Bang on the dowel with your rubber mallet - it will take 2 or 3 wacks with the mallet to empty your K-Cup. It's surprising how much effort it takes to crush a K-Cup!
- Lift out the wooden dowel and crushed K-Cup and start over.