Refilling Keurig K-cups

(Update: I have published a summary of all my posts on Reusable alternatives to K-Cups, which includes a detailed table of the features of the Keurig My K-Cup Reusable Coffee Filter, the Ekobrew Refillable Cup for Keurig K-cup Brewers, the Solofill Refillable Cup For Keurig K-Cup Brewers, the My-Kap Kaps for refilling K-Cups, and the EZ-Cup refillable cup for Keurig brewers).

Keurig single-cup coffee brewers are handy for certain applications.  I work in a university building where lots of staff and volunteers have access to the coffee pot.  Certain times of the year, my crew and I spend about 15 minutes of every hour in the building.  If we brew a pot of coffee, someone else inevitably drinks most of it before we get back at the kitchen, or our stints in the field result in coming back to cold or over-cooked coffee. The Keurig is a perfect solution — brew a very quick, fresh single cup when we have our little interludes.

The issue we have is with excess packaging. The used plastic K-Cups are not recyclable.  I wrote to Green Mountain Coffee Roasters, which owns a large share of Keurig Corp. and manufactures K-Cups, regarding plans to make the K-Cups recyclable. They replied:

“We are not satisfied with the current environmental impact of the K-Cup packaging used with the Keurig system.  We have signed an agreement with one of our materials suppliers for the Keurig K-Cup product to jointly fund research on the application of renewable materials for the K-Cup.  One option may be to develop a brewing system that uses a photobiodegradable K-Cup with a non-metalized lid.”

Bravo to Green Mountain that they are actively pursuing a solution! But then, this company does so much for sustainability, their efforts don’t surprise me.

Reuse is a form of recycling, so I decided to find out if I could refill a used K-Cup with my own coffee successfully.  It’s pretty straightforward — just make sure that the product used to reseal the cup is Glad’s Press and Seal.  This stuff is not like regular plastic wrap, and works like a charm.

Here’s how you do it:

1. Get all the foil off the rim of your used cup, and make sure the rim is dry before applying the Press and Seal.
2. Try to rinse as much coffee out of the filter in the cup as possible.  It doesn’t really seem to matter too much whether the coffee is rinsed out when it’s still wet or if it’s dried out.
3. Grind the coffee very fine — there is not much time for the water to soak the grounds and you need as much surface area exposed as possible.
4. Fill the cup to about 3-5 mm from the top with ground coffee — you can tap the cup to settle the grounds, but don’t pack it down. I tried it and it created overflow due to the force of the water going through the grounds. This amount of coffee is probably similar to the extra bold K-Cups,which have more coffee in them than the regular K-Cups; I personally find most of the regular ones produce pretty insipid brew.  Likewise, although I prefer light roasts, they come through as weak in the Keurig, so darker roasts are best.  But experiment — your tastes may vary. Overall, I use the Keurig for convenience — it’s not for outstanding coffee, no matter what you use.
5. Cut two small squares of Press and Seal per K-Cup.  I’ve tried both one and two layers, and two work better.  The squares only need to be large enough to overlap the edge and stick to about 10 mm of the sides of the cups.
6. Holding a square taut, place it on the top of the K-Cup so it is nice and tight, and press along the rim.  Then seal it along the underside of the rim and the side of the K-Cup.  Repeat with other square.
7. Viola! Ready to use.  Important: when you place the refilled K-Cup in the brewer, make sure to line up the hole on the bottom with the pin in the brewer.

The limiting factor in the number of times a K-Cup can be refilled is clearly the inner filter. Eventually, it will get too clogged with fine particulates; I suppose it might also rip or get a hole. Misaligning the bottom hole (step 7) will also retire a K-Cup.  So far, I have reused a single K-Cup 5 times without any noticeable change in the flavor of the coffee.

Refilling K-Cups in some ways defeats the convenience of the Keurig system, but since I grind coffee daily at home, refilling a couple of cups is no big deal.  Green Mountain also sells a product called My K-Cup, a plastic and mesh filter assembly for ground coffee that is used in place of a K-Cup.

Finally, my spent K-Cups are also repurposed, seeing a new life as filter cups for my pitfall traps, where insects collected in fluid-filled containers inserted flush with the soil must be strained and dried before being examined and identified. K-Cups work perfectly for this, as the bug-containing cup at left shows.  Samples can even be stored in them, as the cups are also easily labeled with a felt tip marker.

I imagine you could also start seeds in the K-Cup (the space between the bottom of the filter and the bottom of the cup could hold some water which would wick up the filter, and the hole in the bottom would provide drainage). Creative types could find other uses for old K-Cups.  Feel free to post them in the comments!

Posted in Coffee-related products,K-Cups/Keurig brewers: alternatives