The Coffee Beans used for making espresso are usually blends of 2 types. Coffea Arabica is regarded as the more prestigious while Coffea Canephora (AKA Robusta) is the easier to grow and therefore costs less. Arabica is the less acidic kind with a rounder, chocolaty, hazelnut taste. The Robusta is higher in acidity and more bitter. The key is to blend both and achieve a sensuous balance, with Arabica constituting the majority of the composition. Some coffee producers prefer to use the more refined and expensive Arabica as the sole variety.
Like grapes for winemaking, coffee beans have different characteristics depending on location, altitude, weather etc. Coffee beans from Brazil tend to be sweet and robust while Colombian beans are more delicate and fruity. Brazil produces the most amount of Arabica. Central American countries such as Costa Rica and Guatemala produce coffee beans with an acidic, chocolaty hint. India produces spicy and bitter coffee while African countries such as Ethiopia and Kenya produce beans with fragrant notes and flowery hints. Asia produces the most amount of Robusta.
The Process from the plant to cup is long and boring. Besides having good quality beans, the main thing that counts is the roasting. After the harvesting and drying, the beans are selected for the roasting. Some coffee producers prefer to create the blend of different beans before the roasting so as to assure a homogenous aroma and taste. The process is called torrefazione or tostatura and turns the green coffee beans dark. It begins with a drying phase, which sucks out the moisture and takes up half of the roasting time. Then comes the roasting, where coffee producers can opt for varying degrees of roast from light to dark. Again, the roasting is the most important part of making good coffee. That is why the best espresso is Italian (Neapolitan). It is made there specifically with a taste in mind. After the roast, the beans are cooled off and then ground. The grinding is also an important step and a slightly finer ground is preferred for espresso.
La Macchinetta (Moka Pot)
Invented by Renato Bialetti, it can also simply be called “la caffettiera”. Moka is a coffee maker that's composed of three parts. The bottom is filled with water up to where it meets the valve. The middle piece is a filter for placing the ground coffee. The top chamber collects the freshly brewed coffee. Once heated on a stove, the pressure from the steam pushes the water through the filter into the second chamber containing the ground coffee. The top chamber collects the freshly brewed coffee. Moka pots are most commonly found in Italians' homes. Moka pots can make good coffee but they lack the necessary pressure to create the all-important “crema” (cream that is found on top of truly great espresso).
La Caffettiera Napoletana (AKA Cuccumella)
This is the traditional, old-school Neapolitan coffee maker. This is a Neapolitan flip coffee pot which is not used much anymore due to the time consuming process and experience required to use it. The coffee made in this type of pot usually has a slightly different grind, in between an espresso and drip coffee (American style). The pot is composed of a few pieces. It has a bottom part, which holds the water. The middle chamber holds the ground coffee and has a filter on top. The top chamber is a container with a serving spout. After the water is brought to a boil, the pot is taken off the stove and flipped upside down. The hot water that was in the bottom container is now on top and starts to filter through the ground coffee and drip into the serving pot. During the 2 - 3 minute process, some people put a “cuppitiello” or small cap made of aluminum or even newspaper over the spout to cover it and prevent the hot air from escaping to keep the coffee hot.
Piston Driven Espresso Maker
Though no longer used, this ornate machine requires the operator to manually pull the lever to allow the water to pass through the ground coffee. These machines are tough to use but nice to look at with their brass, copper, or chrome exterior and the characteristic eagle perched on top.
Pump Driven Espresso Maker
This is the most common machine seen in an Italian coffee shop, which is called a “bar”. In my opinion, these machines make the best espresso. There is no manual pressure applied. Instead, a motor driven pump provides the necessary force to brew the coffee in about 20 seconds. A circular container attached to a long handle is filled with the ground coffee and gently patted down. It gets placed into the machine and what comes out (if made properly) is enough to make you believe in God.
Lavazza Espresso Point Capsule Machine
A patented coffee maker that is extremely easy to use. You pop in a cartridge containing ground coffee and press a button. That's it. And the coffee is pretty good, too.
Automatic Espresso Machines
These machines come in Semi Automatic, Automatic, and Super Automatic and essentially are idiot proof.