For centuries, coffee has played a far more important role in the world than most people realize. Of course, it’s one of the most popular beverages in disparate cultures around the globe. Coffee has launched financial dynasties, fomented revolutions and started nearly as many mornings as the sunrise. To fully understand the allure of coffee, you have to look at it in several aspects.
Coffee Flavour
The chemicals alluded to above – and their countless interactions during roasting and brewing – are responsible for the taste, aroma and other qualities by which we judge a cup of coffee. Coffee tasters have catalogued hundreds of distinct aromas and flavours in coffee. Each cup of coffee you drink is unique, the result of a process begun in the nutrient-rich soil in which coffee beans are grown and accomplished only after meticulous processing and roasting when the ground coffee is combined with hot water. Along the way, the flavour and aroma of coffee are affected by hundreds of factors, including:
- Quality and nutrients in the soil
- Amount of rain and sun during the growing season
- Variety of coffee plant
- Elevation at which the coffee grows
- Ripeness of the coffee cherries at harvest
- How the coffee cherries are processed
- Storage of the coffee beans before and during shipping
- Age of the coffee beans
- Roast parameters like speed and temperature
- Length of time between roasting and brewing
- Blend of coffee beans used to make the coffee
- Relative coarseness of the coffee grind
- Method of brewing, including water temperature and length of brewing time
- Temperature of the coffee when you drink it
Each one of these factors can profoundly affect one’s sensory experience of coffee for better or worse. Specialty roasters seek out coffees that are grown and processed to the highest standards and apply their knowledge and experience to determine the optimal roast level (and blend, if applicable) for each coffee they sell.
What is your favourite coffee roast?
The degree to which coffee beans are roasted is one of the most important factors that determine the taste of the coffee in the cup. Before roasting, green coffee beans are soft, with a fresh “grassy” smell and little or no taste. The coffee roasting process transforms these raw beans into the distinctively aromatic, flavourful, crunchy beans that we recognize as coffee.
Other factors of course enter into the complex equation that determines your coffee’s taste. Two coffee varieties, from different countries of origin or grown in different environments, are likely to taste quite different even when roasted to the same level (especially at light to medium roast levels). The age of the coffee, the processing method, the grind, and the brewing method will also affect the taste. But the roast level provides a baseline, a rough guide to the taste you can expect.
The most common way to describe coffee roast levels is by the color of the roasted beans, ranging from light to dark (or extra dark). As coffee beans absorb heat in the roasting process, their color becomes darker. Oils appear on the surface of the beans at higher temperatures. Because coffee beans vary, color is not an especially accurate way of judging a roast. But combined with the typical roasting temperature that yields a particular shade of brown, colour is a convenient way to categorize roasting levels.
Roast level preferences are subjective. The roast level you like may depend on where you live. In the United States, folks on the West Coast have traditionally preferred darker roasts than those on the East Coast. Europeans have also favoured dark roasts, lending their names to the so-called French, Italian, and Spanish roasts that dominate the darker end of the roasting spectrum.
Light Roasts
Light roasts are light brown in colour, with a light body and no oil on the surface of the beans. Light roasts have a toasted grain taste and pronounced acidity. The origin flavours of the bean are retained to a greater extent than in darker roasted coffees. Light roasts also retain most of the caffeine from the coffee bean.
Light roasted beans generally reach an internal temperature of 180°C – 205°C (356°F – 401°F). At or around 205°C, the beans pop or crack and expand in size. This is known as the “first crack” (for the “second crack,” see below). So a light roast generally means a coffee that has not been roasted beyond the first crack.
Some common roast names within the Light Roast category are Light City, Half City, Cinnamon Roast (roasted to just before first crack), and New England Roast (a popular roast in the northeaster United States, roasted to first crack).
Medium Roasts
Medium roasted coffees are medium brown in colour with more body than light roasts. Like the lighter roasts, they have no oil on the bean surfaces. However, it lacks the grainy taste of the light roasts, exhibiting more balanced flavour, aroma, and acidity. Caffeine is somewhat decreased, but there is more caffeine than in darker roasts.
Medium roasts reach internal temperatures between 210°C (410°F) and 220°C (428°F) — between the end of the first crack and just before the beginning of the second crack.
Common roast names within the Medium Roast level include Regular Roast, American Roast (the traditional roast in the eastern United States, roasted to the end of the first crack), City Roast (medium brown, a typical roast throughout the United States), and Breakfast Roast.
Medium-Dark Roasts
Medium-dark roasts have a richer, darker colour with some oil beginning to show on the surface of the beans. It has a heavy body in comparison with the other roasts.
The beans are roasted to the beginning or middle of the second crack — about 225°C (437°F) or 230°C (446°F). The flavours and aromas of the roasting process become noticeable, and the taste of the coffee may be somewhat spicy.
Among the most common names for a medium-dark roast are Full-City Roast (roasted to the beginning of the second crack), After Dinner Roast, and Vienna Roast (roasted to the middle of the second crack, sometimes characterized as a dark roast instead).
Dark Roasts
Dark roasted coffees are dark brown in colour, like chocolate, or sometimes almost black. They have a sheen of oil on the surface, usually evident in the cup when the it is brewed. The coffee’s origin flavours are eclipsed by the flavours of the roasting process. The coffee will generally have a bitter and smoky or even burnt taste. The amount of caffeine is substantially decreased.
To reach the level of a dark roast, coffee beans are roasted to an internal temperature of 240°C (464°F) — about the end of the second crack — or beyond. They are seldom roasted to a temperature exceeding 250°C (482°F), at which point the body of the beans is thin and the taste is characterized by flavours of tar and charcoal.
Dark roasts go by many names. As a result, buying a dark roast can be confusing. Some of the more popular designations for a dark roast include French Roast, Italian Roast, Espresso Roast, Continental Roast, New Orleans Roast, and Spanish Roast. Many dark roasts are used for espresso blends.
Source: coffeecrossroads, Brian Lokker
