Espresso is a small cup of strong coffee produced on a espresso coffee machine. It is a concentrated coffee drink brewed by forcing hot water under pressure through finely ground coffee. Any type of coffee bean can be used to make espresso coffee.
The caffeine in espresso varies according to the species of the coffee plant. Coffee Robusta has about twice as much caffeine as Coffee Arabica.
Caffeine content in coffee is determined by the length of time that the beans are in contact with the water. Ideal extraction of espresso takes approximately 25 seconds. Regular brewed coffee is in contact with the water for much longer.
There are many different ways of brewing coffee, and espresso is just another coffee brewing method. When is properly brewed, an espresso will feature a layer of rich dark golden cream, called crema on the surface. This crema is one indictor of a quality espresso.
Each cup of espresso is made individually and then quickly served.
A normal single cup of espresso is approximately 1 to 1.5 ounces of beverage, using approximately 7grams (1 tablespoon) of ground coffee and brewed over about 25 seconds (25 to 30 seconds).
A normal double cup is between 2 and 3 ounces, using double the volume of coffee grounds (the same time - 25 to 30 seconds).
A single serving of espresso coffee is called a "shot". Two servings are called a double shot or Espresso Doppio.
Espresso contains about 100mg of caffeine per 2 ounce cup, but values ranged from 58 mgs up to 185mg.
An average 8 ounce cup of espresso has about 2 to 3 times as much caffeine cup as an average cup of instant coffee. An 8 ounce cup of espresso has 3 -4 as much caffeine as an 8 ounce cup of regular brewed coffee.
Reason why most people believe that espresso has more caffeine than regular is that espresso coffee is roasted much darker than drip coffee and darker roasts create compounds which are much bitterer. The bitter compounds that arise in darker roasts are not due to more caffeine.
It is known that caffeine is more quickly assimilated when taken in concentrated dosages, such as an espresso cup. Because an espresso cup has about as much caffeine as a cup of strong coffee, servings for espresso are much smaller.
Milk added to espresso will dilute the caffeine content and reduce the taste of the caffeine.
Note: All figures are approximate, this site does not provide medical advice, diagnosis or treatment.