Espresso is a method of brewing coffee, otherwise known as an extraction method. It differs from other forms of coffee brewing in that espresso forces a small amount of hot water, at pressure, through finely ground coffee. The result is a stronger, more robust, but smaller coffee drink with a layer of natural foam on top, called crema.
While espresso is higher in caffeine, per ounce, than regular brewed coffee, one or two shots of espresso normally have less caffeine overall than an 8oz cup of coffee.
Crema is the thick layer of foam that gathers on the top of a correctly brewed shot of espresso. This foam is the result of two things: carbon dioxide that is off-gassed as the pressurized water passes over the freshly ground coffee and the emulsification of oils in the coffee that are suspended in tiny micro bubbles. Crema blooms in your cup in what is known as the guinness effect.
At Flair, we use crema as our primary success indicator. Getting crema means you have brewed your espresso correctly. Not getting crema means that you need to adjust one of the four major inputs in brewing espresso with Flair: your coffee beans, your grinder, resistance in your coffee bed, and water temperature, as seen below. Continue on to our “Before Brewing” section for more information.
To learn more about how these inputs affect your espresso, click below.