What Are K-Cups? How Do K-Cups Work?

What are K-cups?

If you ever asked yourself ‘What are K-cups?’ or wondered ‘What is in a Keurig K-cup?’, hopefully, this post will answer your questions. Take a look at the video above (and try to ignore the cheesy 1970’s music that Keurig decided to use). The video does an excellent job of showing how the Kcup is designed at the factory, and how it works in the brewing system. In addition, I’ve also provided some additional information about how the K-cup works and the cost of operation not included in the Keurig video.



It is highly likely that you’ve walked right by a stack of Starbucks Kcups or Green Mountain Coffee Kcups in your local grocery store, and you didn’t even realize it! Kcups are the coffee dispenser used by the company who makes the Keurig coffee maker.  A Keurig machine brews just one cup of coffee at a time utilizing a K-cup dispenser shown below.

Starbucks French Roast Kcup

Starbucks French Roast Kcup

The Kcup is a little plastic container that is about two inches tall that fits down inside the top of your Keurig machine. At first glance, it resembles a single serving of half-and-half or Coffeemate creamer more than something that can potentially brew the best cup of coffee you’ve ever had.

What is Kcup

What is Kcup

The magic occurs inside the Kcup, however, using Keurig’s patented technology.

Let’s walk through what is in the Kcup.

1) The air tight seal and cup lock out oxygen, light, and humidity. This helps lock in freshness and flavor.

2) Inside the Kcup is a little mini paper filter which ensure that no coffee grounds seep through like they can tend to do in a regular coffee maker. Keep in mind that if you use one of the accessory filters that can allow you to put your own coffee in the filter, sometimes those filters will allow a ground of two of coffee to seep into your coffee cup. The pre-sealed K-cups, however, do not allow this to happen.

3) Inside the filter for the kcup is coffee that has been ground to ensure it is too large to pass through the filter and in just the right amount to deliver the strength of coffee the consumer desires. Light to medium strength kcups tend to contain approximately 10 grams of coffee while bold or extra dark kcups tend to have approximately 12 grams of coffee inside. The darker roast and extra 2 grams of coffee help the bold kcups deliver a stronger tasting coffee.

4) Water is delivered into the kcup for brewing through a needle that punctures the top of the kcup when the Keurig coffee maker lid is closed after inserting the kcup. You should use distilled water for the best tasting cup of coffee. This keeps inpurities from depositing scale on your brewer, and it also improves the taste. The water is steamed by the Keurig machine to the point of boiling, and then it is injected into the kcup. When you insert the kcup into the Keurig machine, a needle also punctures the kcup from the bottom. The pressurized water brews the coffee while also forcing the brewed coffee out the bottom of the kcup filter, and then into your coffee mug. The air-tight lid prevents any of the brewed coffee or coffee grounds from seeping out the top, and the filter prevents any coffee grounds from filtering into the bottom portion of the kcup prior to pouring into your cup.

How the Kcup Brews Coffee

How the Kcup Brews Coffee

Above is a diagram describing how this process works. The idea is ingenious, and fortunately for all of us, it doesn’t work on just coffee. Take a peek around our site for a thorough list of all the teas, hot cocoas, cappuccinos, and ciders that are available in Keurig Kcups. Also, take a look at some of the alternatives available to buying Keurig kcups. There are many disposable and reusable Kcup imitations that have been developed that will allow you to use your own coffee.

Why would you want to use your own coffee in a K-cup instead of in your regular coffee maker?

1) Quite simply – flavor.

2) Because a traditional coffee brewer makes coffee for more than one cup of coffee at a time, each cup of coffee does not use the precise amount of coffee necessary for each cup of coffee that you pour to provide maximum quality and flavor. The coffee also has a tendency to sit for awhile in your pot, so the coffee can either become too cool or take on a burnt taste if left in the coffee pot for too long.

3) Cost – For example, I like Green Mountain coffee, and if I buy the 12-count at my local grocery store (which is the largest size they sell), my kcups cost approximately $0.67 each. On Amazon, I can get the 12-count for $0.62 each. If I buy them in a higher quantity on Amazon, of say, 50 per box, I can lower my cost to $0.60 each.

But let’s do some quick math here. If I buy a 12 ounce bag of Green Mountain Coffee breakfast blend, the cost is $15.28 for a bag on Amazon. There are 28.35 grams in an ounce which means in a 12 ounce bag of Green Mountain Coffee, there are 340.56 grams. Since your average Kcup contains 10 grams, that means I can get 34 cups of coffee out of the bag if I use one of the reusable (Mycup or i-cup) dispensers available from Keurig, Ekobrew, My-Kap, and others, I can get the cost per cup down to $0.45 per cup! If you drink just one cup a day every day, buying a bag instead of the Kcup will save you $80.30 over the course of a year!

There are some drawbacks here. Convenience, the hassle of having to fill the K-cup filter yourself every morning instead of just popping the pre-sealed Kcup into the brewer, and the possibility of some grounds seeping into your coffee mug are all things that you must weigh if you are going to consider using something other than the standard sealed Kcup.

Whichever way you go, you can be assured that your coffee will taste way better than it ever did coming out of a traditional coffee maker. And, instead of having to brew a minimum of 2-4 cups in your coffee maker, and ending up throwing out half of that because you didn’t drink it all, you’ll only be brewing what you are actually drinking. So whichever type of Kcup you decide to use, you will STILL be saving money over the use of your traditional coffee maker! So, pour yourself a cup and enjoy!