Roasting coffee beans. Caramelization. Maillard reactions. And the secret Southeast Asian recipe for great coffee.
To get a good coffee, we have to start all the way from the beginning. From the quality of the coffee beans that are picked, to the temperature, technique and time used for roasting coffee beans, they all affect the taste and aroma of the cuppa we just brewed.
Roasting coffee beans is particularly interesting. Our cup of coffee has 800 over organic compounds. How bitter they are, and how much of a punch they pack depends on the science that is found in the beans when we are roasting coffee beans.
During roasting, as the temperature rises to 140°C/284°F, the Maillard reactions begin. Dried green coffee beans contain 8-12% protein. The amino acids in the proteins react with the sugars under heat. They form new flavor compounds that react with more amino acids to form larger molecules.
As the temperature rises to 160°C/320°F and higher, caramelization begins. The sucrose in the bean is broken down by heat into its simple sugars fructose and glucose. Water molecules are lost as the sugars become dehydrated, and what is left of the sugar molecules combine to form a larger molecule. These large molecules react further to form new compounds and polymers,
In both reactions, the brown of the bean turns progressively darker, and a wide range of flavors and volatile compounds are released. This gives us the complex range of flavor and volatile compounds that we have come to associate with the taste and aroma of coffee.
We can influence this range of flavors and aromas. In parts of Southeast Asia for example, butter and sugar are added to the roasting coffee beans. The additional proteins, amino acids and sugars give a boost to the Maillard reactions and caramelization.
In Singapore and Malaysia, butter or margarine is added, thus lending an “especially rich, dark character”, giving us a drink that has a “subtle creaminess” (see the first photo). And in Vietnam, the beans are coated with butter and a small amount of sugar to produce a “butter roast” that gives Vietnamese coffee (see below) its distinctive character.
Choose to be butter and like me to discover more. All you need is a minute a day to explore the world’s marvels through the phenomenon of food!
photos: in order – istockphoto/WS_Low; depositphotos/laengauer; nioloxs; istockpoto/fpdress; depositphotos/nuchylee