Living in Australia, we're pretty blessed to have espresso coffee available in most cafe's and shops. Thanks to a strong Italian influence, especially in the development of early 'cafe culture', espresso style coffee is very mainstream, and has been for over 25 years.
I do believe that once you've had this Italian style coffee, it is hard to go back to regular drip filter coffee, although French plunger coffee can be fantastic too. Of course, when you need a 'pick-me-up', any coffee will do!
What is the difference between drip and espresso coffee? Italian coffee is made very differently. It uses a high pressure to force water through the ground beans. Interestingly, whilst the water is very hot, it is not boiling. And the beans themselves are ground very fine and smooth. Contrary to some commercial presentation, this style of coffee is not dependant on one type of bean or roast. It is the process of making the beverage that makes it espresso coffee, nothing else. When a cafe refers to a dark, or stronger roast as an espresso roast, it is no more than an idiosyncrasy of marketing. All coffee beans used to make Italian coffee could be called espresso beans or roasts.
Espresso coffee has a foamy, creamy top made of protein, vegetable oils, and sugars. These all come from the beans, as do the dissolved solid that make up a higher percentage in Italian coffee. This process of coffee making produces a beautiful, intense flavor and aroma.
There is both an art and a science to making a good cup of espresso coffee. Modern coffee chains, particularly the franchises, use standardized temperatures and methods, whereas in Italian communities it is a combination of experience, intuition, individuality, and tradition. The franchises don't even come close to the quality of the coffee made by a good barista using the traditional Italian approach. Having said that, there are a lot of ordinary (and some downright bad) baristas out there who could possibly do well with following a more standardized approach.
To make good espresso coffee, you have to be careful about the temperature of the water used. If it is too cool, the result will be sour. If it is too hot, it can be bitter. Similarly, if you are heating milk to mix with it, burning or overheating the milk will affect the quality of the drink. This is particularly true when using soy milk - overheating it can cause it to separate, and the taste is very bitter and unpleasant. Unfortunately, this is sometimes the case with inexperienced baristas.
The shot of coffee made by the espresso coffee maker also has to be used immediately. When it is left for any length of time, it begins to oxidize, and the quality deteriorates. Most commercial coffee houses have policies taking this into account. And it's a good thing to remember if you're making coffee with home equipment.
Founder of Atitlan Network