Monthly Archives: February 2012

How Does a Keurig Work?

The Keurig has been on the Coffee Whisperer’s test bench for about two months now.  I’m impressed.  Does it make the absolute best cup of coffee that I’ve ever had?  No.  But it does create a perfectly drinkable cup with the lowest effort of any coffee system, including instants.  How does the K system make this happen?  How does it turn ground coffee into brew in under a minute?  It does this by blending together two traditional ways of making cafe:   It is part drip, part espresso.  A glimpse inside a K cup will illustrate this.

This cutaway view will show you what you’d see if you tore a used K cup apart … there’s a paper filter bonded to the top of the cup.  The cup holster assembly punches a hole in the top foil and pops a smaller passageway  in the bottom.  The 192 degree hot water is pushed through the top hole under pressure and moved through the grounds.  While not extremely high pressure, it IS greater than standard drip coffee makers that rely on gravity to pull the hot water down through the coffee and filter medium.  This pressurized process allows the 8- 10 ounces of water to move through the device in under a minute, extracting the flavors of the final product.  So while there are qualities of a drip system in place, the water mimics the characteristics of a pressurized espresso system.

The difference comes into play when it’s time to clear the spent grounds.  A espresso machine will require a swift rap on a knock box or trash bin to release the coffee “puck” and then a rinse under running water to clean the portafilter.  Then there’s some brushing to clean the metal screen that distributes water from the group head.  The Keurig requires a lift of the handle and cup removal.  We’ll talk later about the need or wisdom of running an empty shot through the machine as part of regular maintenance.  But here’s the real magic of the Keurig:  it’s EASY.  It’s easy to use, and easy to clean.  No brainer, grab a cup and you’ve got it  … coffee maker.  That is indeed the attraction of this system, you can’t make a fresh cup any easier.  Are there some downsides?  Any compromises?  Yes, sure.  But you get a solid cup without a bunch of hassle.  Actually no hassle.

And that’s how a Keurig works.   Basically.    There’s buttons and features and stuff.  But if you’re interested in how the coffee comes out….well, there you are.