[gravypod]

Coffee is a combination of the following ingreedients:

   * Water
   * Beans filled with caffine

Water can be recived from a good filtering system [0], mixed with a choosen water profile (common development of breweries), run through an electric water heater, taken to tempature of 195F to 205F, then finally pushed through the ground beans.

An espresso is usually steamed so you'd do the same process but use forced steam then run the evaporated gass through a condensation colum.

It's very doable and probably would yield more ROI/cup because you'll better be able to use time, power, and grindes to better deliver. Also the user experiance of walking up to a wall, clicking a few tick boxes, swiping a card and instantly getting some liquid spit into a cup that is exactly what you ordered sounds a lot nicer for some people.

[0] - http://www.homedepot.com/p/Triton-DI100-GPD-Aquarium-Water-F...