This is a guest post by Keith Douglas. Learn more about how you can guest post for Daily Shot Of Coffee.
If you have spent time watching espresso being made, then you’ve heard the telltale build up of water pressure, followed by that lovely release that leads to a nice, foamy cup. The basics are actually quite simple, and they are time-tested.
Therefore, of course, those with a bit of engineering expertise have taken the time to improve the process. If you have been in a home goods store lately, you have likely noticed the rise in popularity of pod espresso machines. As such, you may have asked yourself a simple question “How do pod espresso machines work?” The answer is actually quite simple, but still interesting.
Let’s Start With Coffee Brewing 101
To understand how a pod espresso machine works, you must first take the time to go back to Coffee Brewing 101. Coffee is a marvelously simple beverage, requiring little more than hot water and ground-up beans.
The basic process has been unchanged by time, even if a few technological tools have made it a bit easier. One simply takes a copious amount of hot water and pours it over the grounds. The water then, bit by bit, seeps through the beans and a filter, dripping down into a large pot. The beverage itself is nothing more than the filtered combination of the grounds and water, but produces a unique flavor.
Heat & Pressure
The modern espresso machine brought two additions to the table – heat and pressure. Like a standard coffee maker, an espresso machine provides the necessary heat for the beverage, allowing consumers to avoid the tedious process of heating up the water on their own.
Unlike a coffee machine, though, an espresso maker works to force water through the espresso grounds. A pressurized pump shoots the heated water through the grounds at an incredible rate (about 220 psi of pressure), creating a shot of espresso in under thirty seconds.
What About The Pods?
The pod espresso machine works in a manner similar to the traditional machine. The heating reservoir is still in place, as is the vaunted pressure nozzle. In fact, the pod machine only has two major differences from the traditional machine – the method of espresso storage and the level of pressure.
Unlike a traditional machine, the pod espresso maker does not require the use of loose espresso grounds tightly packed into a cone. Instead, it requires the use of one of several proprietary pod designs.
Discs, Cups or Traditional Capsules
These may be discs, cups or traditional pods, but they serve essentially the same purpose as the traditional cone. The coffee is packed in tighter, though, creating a more efficient use of grounds. These grounds will still have water forced through, of course, but in a manner that is more efficient than the traditional pressure method.
Of course, pressure is still going to be the key to a great shot of espresso, and the pod machine leaves relatively little to chance. Pod espresso makers tweak the design of the stand nozzle, allowing for more efficient water flow into the cup.
The machine makes a small puncture on either side of the pod, allowing a directed stream of pressurized water to shoot through and fill a cup. This provides a significantly smaller margin for error in the water’s path, thus reducing the amount of time necessary to fill the cup by several seconds.
Though not necessarily a huge step in efficiency, these cups do remove some of the guesswork from creating a perfect shot of espresso. The grounds held within are always properly packed, and the higher-pressure nozzle is coupled with the design of the pod in such a manner that one is virtually guaranteed a perfect shot every time.
It might be surprising to note how similar a pod machine is to a traditional espresso machine. In many ways, this is because espresso machines have always used the same basic principles as the modern pod coffee maker.
It simply took a bit of ingenuity to adapt the pod process to espresso in a manner that made sense, and the addition of the pods and cups to the brewing routine has helped amateurs to create perfect espresso shots without having to take the time to fuss over the quality or packing of their grounds.
Self confessed espresso addict and singer/songwriter Keith Douglas writes for www.TheCoffeeMeister.com to help people get into coffee. He also has a music website at www.KeithDouglasMusic.com which has nothing to do with coffee but does have some cracking songs on it
Photo by d50studio.