There’s nothing better than a steaming shot of espresso to wake up your senses. The best way to enjoy espresso is by making it yourself at home with a good grinder and a home espresso machine. One of the most important ingredients in good espresso is freshly roasted beans. Ever wonder what goes into the roasting process and what some of the terminology means when it comes to various roasts available on the market today? In this article, we'll discuss all of this and more.
Espresso coffee originated in Italy in the late 1800s (see our blog for more of the history). While it’s made from the same coffee beans as regular coffee, espresso is far stronger and richer in taste and aroma. This is thanks to the way that espresso is prepared. The original espresso extractions were from dark roasted beans which have a stronger, more robust flavor and were perfect for standing up to the large temperature fluctuations in the first espresso machines. Dark roasting persisted for years as the way to roast coffee beans for espresso.
One of the best things about espresso today is that it’s not limited to a certain type of coffee roast. Better yet, with every roast type that you try with espresso, you’ll get a totally different result each time. Now, let’s take a look at how coffee roasting can change the taste, aroma, and texture of your espresso. The roasting process is what separates good espresso from the extraordinary.
As you probably know, coffee beans are available in light-roast and dark-roast forms, and every combination in between. Each one of these roasts has a distinctive flavor, smell, body, and caffeine content. Each coffee varietal and type exhibits its own unique characteristics including body, texture, and flavor. Flavor profiles can range from sweet to earthy, fruity to floral, and nutty to chocolaty. The texture of coffee has been described as smooth, syrupy, and creamy while the body can be heavy, light, or anywhere in between. The way a coffee is roasted will affect each of these characteristics. The lighter the roast, the more natural flavor, texture, and body of the beans can be sensed. The darker the roast, those characteristics tend to evolve into something different. Roasting can give new personality to a coffee. A good roastmaster studies the beans to determine which roast level highlights the best qualities of a coffee bean to bring you the most enjoyment in a cup of coffee.
First, characteristics of flavor greatly depend on the coffee bean. Similar to wine, the variety and type of grape determines the flavor highlights of the wine. Most coffee beans fall into two species (Arabica and Robusta); Robusta is a sturdier species which can withstand harsher growing conditions, has a greater yield, and is less susceptible to pests and disease which results in a lower cost. It also has a higher caffeine content and more antioxidants than Arabica, but tastes bitter to most drinkers. Arabica is a milder coffee but tends to be more problematic to grow as it is susceptible to pests and disease. Because of the smoother and milder flavor of Arabica, it is more highly sought after. Second, not only does it matter the species of coffee, but flavor characteristics are influenced by where the coffee beans are grown, at what elevation, how they are processed and dried, and upon the roast applied to them.
Roasting coffee is a very interactive process. In addition to the aromas given off during roasting, there are also auditory cues in the form of "cracks," and visual cues in the form of color and sheen. Green coffee beans tend to smell green, like grass. The longer they are roasted the more they smell, first, like coffee, then as the coffee beans are roasted, the small amount of moisture still inside begins to heat and expand. As the moisture expands it causes the coffee bean to make a cracking noise. The color of the beans will change from pale green through light brown and, if left long enough in the roaster, to black. The natural oils inside the bean are extracted in the darker roasts imparting a shiny layer.
Light roast beans are easy to tell apart from other coffee beans thanks to their pale brown color. They’re also the driest beans since you’ll find almost no oil on the surface.
The reason behind these two characteristics is that light roast beans are heated for the shortest time out of all coffee roasts. The temperature for roasting these beans doesn’t go higher than 355°F – 400°F, just before ‘first crack’, where the moisture begins to leave the beans. The beans will appear less green or tan, beginning to look like the color of a cinnamon stick. They are completely dry with no oils being secreted.
The best light roasts usually come from the mountainous regions and dry valleys of Africa and South America. Light roasts are sometimes referred to as Cinnamon Roast, Half City New England Roast, and Light City Roast.
Medium-light roast coffees are roasted just into the first crack stage, around 405℉ to 415℉. This is where the beans will start to get a little darker and show flavors from the roasting process usually toasted nuts or brown sugar. These beans will be completely dry with no oils being secreted.
A medium roast coffee is slightly darker than a light roast because it’s roasted at a higher temperature. That’s usually between 410°F – 445°F, well into the first crack stage. The beans will still be dry. The roasting begins to mask less desirable flavors found in the beans.
To find the best medium roasts, go for Hawaiian beans, which are famous for their fruity and delicate tastes. South American beans are also great candidates for medium roasting.
When you try medium roast coffee in espresso, you should end up with a fuller color and flavor than that of a light roast. This roast may also be referred to as Breakfast, American, City, and Regular.
According to baristas and coffee experts, medium-dark roasts are the best candidates for espresso. They’re roasted to just the beginning of the second crack, at around 435℉ to 455℉ . Unlike the previous three roasts, medium-dark roasts have an irresistible aroma that’s a true indicator of the coffee’s taste because all flavors are due to the roasting process with no natural flavor remaining. The beans will be dark brown with just a slight sheen of oil on the surface. The texture of a medium-dark roast is often described as full, rich, and dense.
Medium-dark roasts are available with a wide array of subtle flavors that vary depending on the origin of the beans; Hawaii, Asia, or South America, for example. Other names for this roast are After Dinner, Full City Roast, and Vienna.
The last type of coffee roast is the dark roast, which are also used for espresso and espresso-based coffee drinks. They are roasted well into and sometimes past the second crack stage to a temperature of around 465℉ to 485℉. Coffee beans become deep brown, almost black, with a very oily exterior. This is because, during the roasting process, the heat strips the coffee beans of most of their moisture. As a result, the biggest percentage of caffeine content also melts away. These coffees are ideal for mochas, cappuccinos, and lattes.
Beans planted at higher elevations, more than 3,000 feet, are the best options for dark roasts. So, it's a good idea to choose from Nicaraguan, Cuban, or Hawaiian coffee in this case. Dark roast coffees are referred to as Italian, French, Continental, New Orleans, or Espresso Roast.
In summary, not every bean can or should be roasted at every level. Every bean has its sweet spot that balances acidity with nuanced flavors. A great roaster will run small batches at different roast levels and sample the results using different methods. Not every bean regardless of its roast level is meant to be used in espresso.
The answer to the question of which roast is right for you is – it depends. It depends on what flavors you would enjoy tasting in your espresso, and more importantly, what equipment you have at home to get the most out of the beans you choose. In the next article we'll look at current home espresso machines that have the ability to do pressure profiling wherein the brewing pressure (and temperature) is controlled by the barista during the extraction.