Enjoying a cup of coffee is one of the little pleasures in life that many of us appreciate. Typically, we either brew the beverage at home or have our favorite barista make it for us.
For many people, enjoying a coffee-based beverage begins with opening a bag of roasted beans. However, you might have noticed that some bags are labeled “espresso” or “espresso blend.” You quickly start to wonder if there is a difference between the beans.
The truth of the matter is that there is no difference between an espresso bean and a coffee bean. A coffee bean is just a coffee bean. However the “espresso” label offers some advice to consumer on how to brew the beans.
Typically if a bean is labeled as “espresso” it means that the beans can handle the high pressures (7-9 bars) of water being exerted on them. They are also typically dark roasted.
With that said, these types of beans still work with other methods of immersion. However, the lower quality beans made specifically for immersion brewing won’t work well for pulling a shot of espresso.
Let’s look at roasting process and how it can affect the beans.
It All Starts With Green Beans
It doesn’t matter what type of coffee you are enjoying, they all start out as green beans. Even monsoon coffee, which is eventually a pale yellow, begins as a green bean.
Before the beans are ground and brewed, roasting must take place. During the roasting process, all of the sugars and oils are unlocked from within the bean. It is the roasting process that gives the coffee its distinct flavor and aroma.
The Basics of Roasting
As the name would suggest, the green beans are exposed to high temperatures during the roasting process. The amount of time that they are subjected to the heat is what makes the difference in the roast level.
You likely have a preference between light, medium and dark roasts. The light roast tends to allow you to experience more of the flavor of the bean while the dark roast is strong and robust. The medium roast is somewhere in the middle and is the most preferred.
You can read a more detailed overview of roast levels in this article.
Roasting Steps, Temperatures, and Times
During the roasting process, all of the characteristics, aromatics, and flavors within the bean will be created and balanced. When done properly, it will give you that perfect taste you’re after, regardless of whether you’re looking for an espresso shot or if you want to make the perfect latte.
The First Stage
It all starts with green beans that are dried slowly. During this process, the beans will turn to a yellow color and take on the aroma of popcorn or baked bread. The first stage should not be rushed because you will build on it to create the perfect roast.
The First Crack
The coffee is roasted at 400°F. During the first crack, the bean will turn to a light brown color and double in size. The weight of the bean will also drop by about 5% as some of the moisture is released.
The fact that it is called the ‘first crack’ is descriptive of what occurs. There is an audible and physical crack that takes place due to the evaporation of moisture and the expansion of the coffee bean. As the moisture inside of the beans heats, it forms steam and the resulting pressure causes the bean to crack open.
There is also typically a change in the aroma when the first crack is about to occur. Some people describe it as the scent of baked bread that changes to a sweeter, caramelized aroma. When this begins to occur, you need to start thinking about the following steps that will take place.
Prior to the first crack occurring, an endothermic reaction is taking place. The bean is essentially absorbing heat. As the moisture escapes the bean, the color changes to yellow and eventually, to brown. Once the first crack occurs, it shifts from an endothermic to an exothermic reaction.
After the first crack occurs, the temperature is increased to about 425°F. The light brown bean will turn to a medium brown and the weight will continue to drop. The resultant change in the bean is from a chemical process known as pyrolysis. CO2 is released from the bean and the chemical composition begins to transform.
The Second Crack
This next step occurs after a brief endothermic resting period. During this step, a secondary audible cue will be provided. In most cases, the second crack is a lot more forceful and louder than the first crack. Think of the first crack as a snapping sound and the second crack as more of a cracking or popping.
Balancing a Roast
In order to get a proper roast, you must take the green bean through both the first and the second crack. At that point, you need to maximize the potential of roasting while at the same time, minimizing acidity and bitterness.
One of the biggest and easiest mistakes when roasting coffee beans is to over-roast the bean. Although it may be tempting to make the bean extremely dark, you are going to lose a lot of the sweetness and aroma that make the brew pleasant to drink.
This isn’t only a mistake that is made by home roasters, many companies that roast coffee also overshoot the roasting process.
A shot of espresso should be a pleasant and fulfilling experience. Most people, however, shy away from drinking straight espresso because it lacks sweetness. More than likely, they only use the espresso in milk-based beverages, such as cappuccinos or lattes. Otherwise, you may add excessive amounts of sugar to the finished product.
Maximizing the Potential of the Beans
During the final phase of the roasting process, the sugars in the coffee bean will start to caramelize. Caramelization will result in a dark color but it will also reduce the sweetness.
In order to strike the perfect balance, you should roast the bean long enough so that the caramelization begins to take place. At the same time, you don’t want to roast the bean too lightly or you may end up with a bitter flavor.
The general recommendation is to stop a little less than half way into the second crack.
It’s important to reiterate that there isn’t much of a difference between products labeled “espresso” or “espresso blends.” Coffee beans are just coffee beans with different levels of roast. Products labeled espresso are typically best suited to be brewed with an espresso machine.