What is Espresso Coffee?
We all have those questions that we are embarrassed to ask. Most of us believe that we’re coffee aficionados, but may have learned that term before fully understanding the meaning behind it. While there’s no harm in this, I’m also telling you that there’s no embarrassing question when it comes to coffee.
With that in mind, have you ever asked yourself what is the difference between coffee and espresso?
Most Common Misunderstanding of Espresso
Think about all the different ways you can make coffee. A French press, pour over coffee, and Keurigs, all create unique and different tasting coffee. Espresso is not a variation in the bean, it is a difference in the way you create the coffee. So while all espresso is technically coffee – not all coffee is espresso.
Q: But I thought espresso beans and coffee beans were different?
A: Espresso is not a different type of bean, nowadays most Roasters have a special process for beans that are designed to become espresso. Commonly, roasters will defer to using higher-quality robusta beans to add extra caffeine.
Q: What separates Espresso from other brewing methods?
A: While other methods brewing take time, because they rely on the slow filtering of hot water through the grounds, espresso expedites the process for a fresh cup of coffee. Espresso machines pressurize and push extremely hot water through a very finely packed coffee cake (or puck). This method gives you an extremely complex and caffeine pack shot of coffee in a short amount of time.
Q: Do I need to buy an expensive espresso machine?
A: You do not need an expensive espresso machine to pull a quality shot of espresso. It takes time and patients to learn how to pull a good shot. However, having a quality espresso machine will help with the consistency of the shots.
The Importance of Pressure
The lever of an espresso machine is the key to creating a great shot of espresso. Pressure is extremely important for coffee brewing, it helps develop the crema and oils that go into a fantastic shot. Most of the coffee brewing methods rely on gravity to drive the water through the grounds to make the cup of coffee. If you’re using a French press or Moka pot, the actual pressure applied is minimal compared to most brewing methods. We measure this pressure in “bars”. Your typical espresso machine put shots at around 9 bars, which is roughly equivalent to 130 PSI. Coffee aficionados know that, to have a technical “perfect shot of espresso”, the espresso machine should be pushing 15 bars of pressure.
Creating Espresso: Espresso Grounds & Espresso Pucks
Using fresh espresso grounds to pull your shots is extremely important. It is important to purchase a quality bean grinder so that you can use very fine grounds in each shot. During the brewing process – the more coarse the grounds, the bitter the coffee.
However, Espresso is different. The coffee ground cake (or also called the coffee puck) will determine how well the espresso was extracted. The coffee puck provides more surface area of beans to the water. This creates a more efficient brewing process to create a quality shot in a short amount of time. Note that grounds that are too fine can clog and slow the extraction process.
Characteristics of a Good Espresso Shot
Espresso is traditionally a dark brew served in a small china cup that can fit around 50 ml or about 1.6 Oz. When properly prepared there will be a thick top layer of brown crema, which is the pinnacle of a coffee foam.
What is Crema?
This is the foam on top of a shot and serves as a visual indicator of a well-extracted espresso shot. When the water is pressurized enforced and to the coffee cake a few reactions happen:
- The hot water blends with the coffee oils
- Bicarbonate ions in the water go through a chemical reaction from the exposure to water.
- The change from a high-pressure environment to a low-pressure environment causes bubbles in the espresso.
When all these things happened the top layer of the espresso shot becomes crema. Crema disappears after 30 to 40 minutes depending on how the shot was pulled.
If pulled correctly the actual espresso under the crema will have a very different, but unique taste, feel, and scent. When pulling a shot is shorter. Of water exposure draws out less acid than other typical brewing methods. however, it still retains between 60 and 70% of caffeine per cup.
Even though espresso takes almost 30 seconds to brew it provides a significant amount of caffeine. The process also preserves more of the coffee oils that you would not find in a regular cup of coffee.