Key points of coffee roasting techniques: coffee roasting degree resolution chart can easily analyze the roasting principle.

American Coffee Association (SCAA) Roast Degree Standard This standard uses infrared caramelization tester technology (Agtron) to measure the color of coffee beans to determine the degree of roasting of coffee, and the color from light to dark into eight equal parts made of eight standard color blocks for the coffee industry as roasting identification.

The above colors are for reference only. According to the preference of countries to distinguish the roast degree This is also the earliest coffee roast degree distinction, due to the taste preferences of coffee roast degree in various countries and regions are different, so it is called national or regional roast degree, such as Italian roast, French roast, etc... However, these different preferred baking degrees were integrated and arranged from light to dark to form a baking degree discrimination index, but because the standard was too general, different baking masters had different opinions on baking degrees.

The above colors are for reference only In recent years, Taiwan has mostly focused on the explosion changes during baking to determine the degree of baking.

roasting degree Time point of beans------------------------------------------------------------

Coffee roasting through the burning of fire, the release of coffee aroma, each bean contains the character of the sour, sweet, bitter to the fullest extent, from the tasteless raw beans, to the cup of endless flavor-roasting, is each coffee bean in the long journey, outline the character, the most important stop to nurture the aroma. Whether in a professional roaster, on your own fire or in an oven, coffee beans must undergo several chemical changes during this intense dialogue with the fire at temperatures as high as 450 degrees Fahrenheit (232 degrees Celsius) for about 12-16 minutes, emitting a second popcorn-like crisp sound and losing 15 - 25 percent of their weight. The baking process, like popcorn full of flavor and pleasant bouncing sound. From raw beans, light, medium roast to deep roast, water release again and again, weight loss, volume slowly expand bulge, coffee beans color deepened, fragrant oil gradually released, texture also becomes crisp. Green beans-Each coffee cherry contains two green beans, and the aroma is still deep inside, waiting to be discovered. Green beans contain large amounts of chloric acid, which gradually disappears during baking, releasing familiar and pleasant fruit acids such as acetic acid, citric acid, and malic acid found in wine. Baking just right will bring out these wonderful sourness in moderation, whereas baking too much will completely mask them. Bake 5-7 minutes, beans begin to release water, light green to orange color, exudes creamy roasted vegetables unique aroma. Light Roast-When the beans emit the first soft sound, the volume expands at the same time, and the color changes to a delicious cinnamon color, so it is also called cinnamon raost or half-city roast. Acidity dominates the flavor of light roasted beans, texture and taste are not fully developed, so generally used as canned coffee, can not satisfy the real coffee connoisseur. Medium Roast-When roasted for 10-11 minutes, the coffee beans take on an elegant brown color. New Yorkers like to kick off the day with medium-roast coffee beans, rich milk and sugar at breakfast, hence the name breakfast roast or city roast. Medium roast can preserve the original flavor of coffee beans, but also can release moderate aroma, so Blue Mountain, Colombia, Brazil... For coffee, choose this method of roasting. At 12-16 minutes, the oil begins to surface, beans are burned by the fire pattern to a bright dark brown, called full-city roast, some people think, at this time coffee acid, sweet, bitter to achieve the most perfect balance point, coffee beans character is also clearly characterized. Deep Roast-The darker the color of the coffee beans, the sweeter the flavor. When the oil has been caramelized, the bitterness returns to sweetness and the remaining flavor is endless. It is best for brewing strong Espresso coffee. Therefore, it is also called Italian Roast. Moderate roasting gives life to coffee beans, turning them into sour, sweet, bitter and astringent when they are eaten. However, people who are sensitive to caffeine may wish to choose deep-roasted beans as much as possible, because caffeine will slowly escape during the roasting process, so the deeper the roasted beans, the lower the caffeine content. Tasting suggestions are personal opinions, and the main drinking method varies from person to person.

Source:

Barista-HHC Blog