What Are the Differences between a Light and Dark Roast?
Posted on Monday, December 24 2012 09:55:55 AM in Blog by Trevor Ouellette
Coffee drinking is an art, especially for the large percentage of people who consider themselves coffee-lovers. After coffee processing and before coffee brewing comes coffee roasting. A good cup of coffee is not only affected by the green coffee beans from which the extract came from but also from the process, duration, and temperature that they were roasted in. Both a chemical and physical process, roasting coffee causes the beans to expand and change in all its aspects—color, density, taste and smell. Perfectly roasted coffee beans produce the perfect cup of coffee. Without heat and without roasting, the coffee beans still have the similar chemical structure but lack the delicious taste.
Degree of Roast: Light versus Dark
The main difference between light-roasted and dark-roasted coffee beans is temperature and time. Dark-roasted beans are exposed to longer durations of high temperature while light-roasted beans are applied with less heat at a shorter time. In simple terms, darker beans are more roasted while lighter beans are less roasted. This comparison of the bean’s color is the most popular method of determining the degree of roast. On a more scientific level, a colorimeter can be used to test the heat applied to the coffee beans. The reflectance is tested with infrared light and measured with the Agtron scale.
Science, Color and Sound of Roasting
During roasting, the color of the green coffee beans change to yellow. As more heat is absorbed by the bean, the color shifts gradually from yellow to brown. Oils are produced from the surface of the bean during the later stages of roasting as the bean continues to darken unless it is removed from heat. Sometimes, the color shift becomes unreliable when it comes to aged beans. In general, beans darken as they age, thus compromising the color.
Roasters also consider the cracking sound during roasting to determine the bean temperature. There are two cracking sounds that the bean produces during roasting. These two are considered breaking or threshold points. The first crack happens during the temperature range of 205–207 °C (401–405 °F). This signals the beginning of the light roast. The second crack happens during the range of 224–227 °C (435–441 °F). This signals the beginning of the medium roast.
Commercial versus Home Roasting
Though usually done in a manufacturing nature, roasting coffee can be done in a house kitchen if one has the right home coffee items. This personal treatment of most coffee drinkers allows more handle in customizing the flavor profile of the green coffee beans. Health-wise, roasting coffee affects the caffeine and acidity content of the formula. For this reason, home roasting directly helps those with sensitive stomachs.
Home roasting has become more popular during the turn of the 20th century. As time went by, coffee drinkers have indulged in pre-roasted coffee as soon as commercial coffee roasting companies rose in popularity. Nowadays, the personal touch of coffee-making is seeing a big revival.
Home Coffee Solutions offers a wide variety of light, medium and dark roast single serve coffee and coffee beans for conventional coffee machines. Whatever your preference, we've got a coffee that will suit your tastes. Shop online or visit us in-store to find the perfect coffee roast for you.