What is Espresso?
The word espresso comes from the Italian words caffè espresso which literally means pressed-out coffee. Espresso is brewed by forcing very hot water under high pressure through coffee that has been ground to a consistency between extremely fine and powder. This process extracts a very flavorful concentrated coffee beverage. In Italy, good espresso is defined by the four Ms – Miscela, Macinazione, Macchina, Mano. These four words loosely translates to: blend of coffee beans, the grinding process, the machine, and the person making the espresso.
Espresso was developed in Milan, Italy in the early 20th century, but up until the mid-1940s it was a beverage produced solely with steam pressure. A simple espresso machine uses a pot, a filter, ground coffee and a spout. The as water in the pot is heated pressure builds inside the pot, and the only way for it to escape is up the spout, through the coffee and out of the spout in the top. Since the end of the spout is under water, the pressure forces the hot water up through the spout. Modern day espresso machines have really caught on since the invention of the spring piston lever machine. This machines commercial success changed espresso into the beverage we know today. Starbucks has taken espresso production to a new level and the market continues to grow each year.
How does Espresso Differ from Coffee?
So what makes espresso so much different than regular coffee? For starters it has a thicker consistency than standard drip coffee. It also contains a higher amount of dissolved solids than drip coffee per relative volume. And probably the most noticeable thing when you pay $6 bucks is that the serving is much smaller. Espresso is usually measured in shots, which are between 25 and 30 ml (around 1 fluid ounce) in size. Espresso is also chemically complex and somewhat volatile, with many of its chemical components quickly degrading from oxidation or loss of temperature. Just by looking at it, the most distinguishing characteristic is “crema”. Crema is the reddish-brown foam that floats on the surface and is composed of vegetable oils, proteins and sugars. Crema has elements of both emulsion and foam colloid.