Coffee vs Espresso
Coffee, perhaps the most widely consumed beverage across the world aside from tea, has been around for over a thousand years.
People brewed coffee in virtually the same way for much of that time, until an Italian inventor discovered a new way to brew coffee in the late 1800s. This method became known as Espresso. While they both produce a sort of coffee, Espresso and traditional brewing are prepared in very different ways.
What Is the Difference Between Coffee and Espresso?
Most coffee drinkers prefer one over the other, but not many know why. Some people assume that because they vary so much in flavor, consistency, and caffeine, they must come from different types of beans. In reality, the same coffee beans go into brewing coffee and espresso. The real difference lies in the preparation of the beans and the brewing method used.
The Roasting Process
Preparation is the first part of what differentiates coffee and espresso. Up until the roasting process, the beans that go into coffee and espresso are one and the same. Even after the roasting process, the beans could theoretically be used in either process.
You can roast traditional coffee beans to many different degrees. Lighter roasts will produce very different flavors and consistencies than darker roasts (more on this below). Most coffee drinkers stick to light to medium-dark roasts for their coffee, though dark roasts are not uncommon for coffee lovers who enjoy an intense flavor.
For espresso, you typically roast beans to a very high degree. This produces beans that are less acidic and more oily, which is ideal for the espresso process. Darker roasts also produce more durable beans that will be able to withstand the immense pressure of the espresso machine without vaporizing.
Coffee beans ground for traditional brewing are ground to a moderate degree. Not so little as to have the water miss most of the bean, but not too much as to clog up the filter. There needs to be enough space between the grounds to allow the water to pass through freely with no added pressure. Since regular drip coffee (or pressed coffee like in a french press) is exposed to the hot water for much longer than an espresso, too fine of grounds would increase the saturation and make the end product too bitter.
With espresso, you expose hot water to the grounds for about 30 seconds, so it is important to have very fine grounds to maximize the extraction of the flavor and caffeine. Since espresso machines add an immense amount of pressure, there is no need to have gaps between the grounds. The tightly packed grounds maximize the surface area and allow for better extraction.
The Brewing Process
Drip Coffee/ Pressed Coffee
Although espresso and regular coffee are prepared in somewhat different ways, the biggest difference lies in how they are brewed. With drip or pour-over coffee, hot water is exposed to the ground coffee with no added pressure. The coffee then runs through a paper filter and is collected in a reservoir at the bottom.
Pressed coffee (such as with an aeropress or french press) is where the coffee grounds are exposed to the hot water in a vessel. Then the coffee grounds are “pressed” to the base of the vessel, leaving just the coffee.
Pressed coffee and drip/pour-over coffee are slightly different in that in the later there is no filtering of the coffee through a paper filter. Some coffee aficionados prefer the press since they believe the paper filter absorbs some of the flavors of the coffee.
The reason why these methods have been around for so long is that they require minimal equipment. Espresso machines are relatively complex and require a lot of technology which, until recently, was far too expensive for the average consumer.
Making espresso requires a very specific process. Once the coffee is finely ground, it is tightly packed into what is commonly called a “coffee cake”. The machine then pushes near-boiling water through the coffee cake under extreme pressure.
The pressure in an espresso machine is typically around 9 bars, but can go up to around 15 bars. 9 bars is the same as about 130 pounds per square inch (psi), or 218 psi for 15 bars. For reference, the pressure in a car tire is only about 35 psi.
The immense pressure, near-boiling water, and fine coffee grounds allow the machine to make coffee that is much more concentrated than with regular coffee.
With espresso, the concentrated coffee and caffeine allow it to be mixed with milk, water, or other additions to make a wider variety of drinks. Traditional coffee has a much higher volume, which limits one's ability to make it into other beverages.
The End Product
Regular coffee, because of the different ways it can be prepared and different types of roasts, has a much wider variety of flavors. Lighter roasts are more fruity, floral and tend to be more acidic or “bright”. Darker roasts are smoother, earthier, and full-bodied. The variety of flavors and control over the process is why many coffee drinkers prefer traditional coffee.
The darker roast and shorter exposure of espresso beans remove a lot of the acidity from the drink. This allows the espresso to be strong and concentrated, but not too bitter. Most coffee lovers describe espresso as bolder and more aromatic than regular coffee.
One aspect of espresso that is nearly non-existent in traditional coffee is the crema. This layer of foamish material is why many coffee drinkers prefer Espresso. It also indicates the quality of the espresso.
Crema is the result of several chemical processes in the espresso machine. First, the pressure of the machine “degasses” the bean and releases the CO2. The water’s change in PH level as it interacts with the coffee grounds also interacts with the oils on the grounds and produces CO2 microbubbles. As the coffee exits the machine and goes into the cup it goes from a high pressure environment to a low pressure one--which allows the CO2 in the bean to break through the cell walls.
Crema is a sign of quality (but not necessarily tasty) espresso. The lack of it indicates that the beans are old and the oil has all evaporated, or that the barista mishandled the espresso process.
How Does the Caffeine Vary Between Coffee and Espresso?
A common misconception is that espresso has more caffeine than coffee. While espresso may have a higher concentration of caffeine, the total amount of caffeine in a serving is far less.
How much caffeine is in a shot of espresso does depend on the type of bean and roast, but it varies much less than regular coffee. A single shot of espresso typically has about 40 to 75 milligrams of caffeine. A double shot of espresso typically has 80 to 150 mg of caffeine. This is why many coffee shops will put a double shot into most of their espresso drinks.
The caffeine content of a regular coffee depends a lot on the serving size. An 8oz cup of coffee usually contains about 80-185 mg of caffeine. A larger serving size of 12 or 16oz can have as much as 225mg of caffeine--nearly 5x that of a small shot of espresso.
The caffeine in espresso vs coffee is one of the biggest misunderstandings around the relationship between espresso and coffee. So if you are looking for more caffeine, coffee is the way to go. If you want a small jolt of caffeine, then espresso is the way to go.