What is espresso? Is it a type of coffee bean or blend? A grind size? Another word for coffee?
While the term espresso, or expresso as some people unfortunately pronounce it, is regularly thrown around, it is seldom clearly understood.
Espresso is an Italian method of brewing coffee that produces a dark, dense shot of concentrated coffee topped with a golden layer of crema.
This brew has become cherished around the world, dominating many morning routines including our own. And we think it is safe to say the world wouldn’t be the same or function the way it does without the millions of espresso shots pulled each day.
This article will consider the question ‘What is espresso?’ to understand what an espresso is and why it is savored around the world. So sit back, sip and savor all the different elements that make up espresso.
What is Espresso?
In short, espresso is a concentrated form of coffee that is made when hot water is forced through fine coffee grounds at high pressure. The resulting shot has a thick, almost syrupy body, like liquid honey, and is topped with a layer of crema. The crema adds to the rich, robust flavor and leaves a lingering aftertaste.
Espresso was born out of a desire to reduce the brewing time of coffee. Coffee was already a popular beverage but would take a long time (around 5 minutes) to brew. The solution was an espresso machine that could brew coffee in a matter of seconds.
The invention of espresso machines is usually accredited to Angelo Moriondo from Turin, Italy. In 1884, he patented a steam-driven coffee machine that was more of a batch brewer. Little seemed to come of the Moriondo brewer.
In 1901, Luigi Bezzera, from Milan, entered the scene. He patented several improvements to Moriondo’s design, including introducing a portafilter and brew heads, thus creating a single-serving espresso machine that brewed directly into a cup.
Bezzera lacked the money to take the design further, and in 1903 Desiderio Pavoni bought the patent. He added a few more improvements, including a pressure release valve and steam wand, and then began to produce the machine. The machine was fiddly and still struggled to deliver a consistent shot.
Fast track a few years to the end of WWII, and Achille Gaggia invented the first lever espresso machine, and with it, the saying ‘pulling a shot.’ It was here that crema was also discovered. Ironically, early drinkers were suspicious of this ‘scum’ floating on their coffee. It was only after Gaggia began referring to it as Café Crème that the perception changed. And thus, modern espresso was born… and the rest is history.
How Is Espresso Made? (Extraction Theory)
The SCA defines espresso as:
“Espresso is a 25–35ml (.85–1.2 ounce [×2 for double]) beverage prepared from 7–9 grams (14–18 grams for a double) of coffee through which clean water of 195°–205°F (90.5°–96.1°C) has been forced at 9–10 atmospheres of pressure, and where the grind of the coffee is such that the brew time is 20–30 seconds.”
The SCA highlights several key elements required to create espresso, which we will go into more depth below. Disclaimer: we will go into full-on coffee geek mode, so if that is not you, feel free to skip over this section.
The brew ratio is the ratio of ground coffee to espresso in the cup. This element is one of the most critical things to control the quality of espresso produced. Water is a solvent, so it dissolves all the flavors in coffee. The more water you put in, the higher your extraction will be. But this does come at the cost of strength, texture, and mouthfeel. So you need to find that sweet spot- a well-extracted shot that still has enough texture and body. Most beginners start with a brew ratio of 1:2 to 1:2.5.
Whether you are brewing coffee or espresso, the ideal brewing temperature is 195-205 F. This is the best temperature to ensure optimal extraction. Too cold and your espresso will be under-extracted and sour; too hot and it will be over-extracted and bitter. If you have invested in a decent espresso machine, it should maintain this water temperature throughout brewing.
Some espresso machines allow you to alter the temperature to tweak it depending on the roast level of the coffee beans.
The SCA recommends the water pressure be at 9-10 bars. For those of you, like me, who have forgotten all those high school science lessons, nine bars of pressure is the same as nine times the pressure at normal atmospheric pressure.
Nine bars seems to be the sweet spot before the pressure of the water would compact the puck further, preventing water from moving through.
Many espresso machines have a pre-infusion function, which introduces water at a lower pressure to evenly wet the coffee before the higher pressure is applied. Pre-infusion helps to encourage even extraction.
To brew espresso, you need to use finely ground coffee compacted via tamping. Espresso grind is one of the finest grind sizes, with the exception of Turkish. The fine grind size increases the surface area for hot water to extract all the good stuff out of the coffee. And because the brew time is so short, this is necessary.
The brew time is considered the time from when you start the espresso machine to when it stops. Ideally, the brew time should be around 25 to 30 seconds.
As you can see, good espresso is all about finding the perfect balance between grind size, temperature, and pressure.
The Anatomy of an Espresso Shot
An espresso shot comprises three layers: crema (golden layer on top) the body and the heart (dark liquid on the bottom).
The top layer of an espresso is the crema. This is something that is unique to espresso and is the sign of a properly extracted shot. Crema is made up of bubbles of CO2 that have been surrounded by water and oils. This layer is strong and bitter and leaves a lingering aftertaste.
The second layer of an espresso is known as the body. This is largest portion of a shot and is where a lot of the complexity lies. The body is made up of soluble solids, gases, and insoluble solids. Each element plays a part in contributing to the final flavor, texture, and mouthfeel of the shot.
These three components combine to produce a complex flavor profile with sweetness and clarity.
The final layer of an espresso shot is known as the heart. This is really the foundation of the shot and is a thick, dense syrup that carries the deep flavor and acidity.
How Does Espresso Taste
Many consider espresso to be the very essence of a coffee drink. It has all the same flavors of coffee but intensified. It is rich, bold, sweet, acidic, and has low bitterness. The flavor profile will depend on the roast you are using. However, there are some general characteristics true of all espresso.
Firstly, if you want to order a straight espresso, you need to decide which type of espresso shot you want. An espresso shot is served in special espresso cups known as Demitasse cups.
Secondly, there is a long list of espresso-based drinks you can order.
Caffeine Content in Espresso
Espresso is renowned for being high in caffeine. And while this is true in theory, in practice, it depends on how much you drink. Espresso is generally served in much smaller sizes than coffee, so it often has a similar amount of caffeine in it to brewed coffee.
For any espresso or espresso-based drink, there are around 63 milligrams for a single shot of espresso and 125 milligrams for a double shot of espresso. In comparison, an average cup of brewed coffee contains approximately 95 milligrams of caffeine.
In context, health experts recommend a maximum daily intake of 400 milligrams of caffeine per day for healthy adults. So you do the math; the amount of caffeine in a cup of coffee (either espresso or brewed coffee) makes up around a quarter of your daily recommended caffeine consumption. See our guide to caffeine in a cup of coffee for a more in-depth rundown.
Espresso vs coffee
While technically, espresso is a method of brewing coffee, here we are going to compare the difference between espresso and coffee. Several key differences set the two brewing methods apart.
Grind Size: Espresso uses a fine ground size to increase the surface area, so more coffee beans are exposed to the water. Drip coffee uses a coarser grind size due to the longer brewing time.
Ratio: Espresso is brewed with a high ratio of coffee to water, typically 1:2 coffee to water, resulting in a robust and syrupy shot. Drip coffee uses a lower ratio of coffee to water; anywhere from 1:12-17 coffee to water.
Brewing Method: Espresso is brewed quickly, using an espresso machine to force water through finely-ground coffee in under 30 seconds. Drip coffee is brewed slowly by pouring hot water over the grounds. Brewing takes several minutes.
Pressure: As mentioned above, espresso requires high pressure to brew and develop crema. Brewed coffee relies on gravity to drive the water through the coffee bed.
Serving Size: Espresso is served in much smaller sizes, typically a single to double shot (1 -2 oz). A drip coffee is usually served as an 8oz cup of coffee.
Taste: An espresso shot is concentrated and bold, whereas a brewed coffee is less intense.
The difference between espresso and coffee is quite marked, resulting in two very different ways of drinking coffee. The espresso brewing method is far more complicated and requires the use of specialized equipment (like espresso machines) and precise brewing parameters to produces a decent espresso. In contrast, brewing coffee is often more simple and forgiving.
What is Espresso?- To wrap up
So what is espresso? Espresso is a concentrated form of coffee made when hot water is forced through finely ground coffee beans at high pressure.
It is easy to see why espresso has become a morning ritual for many worldwide. The hissing machine, the dark, dense liquid trickling through, the layer of golden crema floating on top. It is, in many ways, the very essence of the coffee bean. We hope this article has encouraged you to go out and try an espresso- you won’t look back!
Yes, espresso is made with a much higher ratio of coffee to water, resulting in a concentrated and bold shot. It is much stronger than a typical brewed coffee.
No, we wouldn’t recommend it. Brewing espresso requires finely ground coffee beans with a high surface area to extract all the delicious flavors out of the coffee beans. If you use coarse coffee grounds, your espresso will be under-extracted, weak, and lacking crema.
While espresso beans are the same as coffee beans, an espresso roast tends to be a darker roast to minimize the acidity. Lighter roasted beans can be used for espresso, although they tend to be more acidic. If you plan to drink espresso straight, a single-origin espresso roast is an excellent place to start.
If you want to brew espresso-based drinks, the other popular option is to buy an espresso blend, which blends different coffee beans to achieve a more balanced flavor profile. See our guide to the best espresso beans for some good options.