Why do some coffee bags use descriptions like nuts, chocolate, and caramel? Different chemical reactions during the coffee roasting process cause different perceptions of aromas, including something called sugar browning. Sugar browning ultimately alters how we perceive flavors and sweetness in our favorite cup of coffee.
What is sugar browning?
Sugar browning is a classification of specific aromatic compounds found in roasted coffee, primarily categorized as nuts, chocolate, and caramel. Sugar browning occurs during two different chemical reactions that take place during the coffee roasting process; the Maillard reaction and caramelization.
The Maillard reaction is one of the most complex chemical reactions to take place during roasting. During it, amino acids act as catalysts with reducing sugars, resulting in a non-enzymatic sugar browning process. It’s very similar to the chemical reaction that occurs when you brown a steak, for example.
The length and momentum of the Maillard reaction will affect sugar browning to determine the body and sweetness of the coffee, as well as the complexity of the sugar browning notes found within the final product. With the steak example, more depth and complexity is achieved.
As the length of the Maillard reaction extends, simpler flavors like nut turn into more complex flavor compounds like walnut or almond. Caramel increases in complexity to maple syrup or honey. Chocolate notes develop into dark chocolate or even vanilla.
TLDR; sugars and amino acids are reactive, resulting in the non enzymatic browning of sugars present in the coffee, resulting in aromas.
Sugar browning continues within the roast as the oxidation of sugar begins under a high temperature, happening at the end of the Maillard reaction. The degree of browning and caramelization here is dependent on the temperature and end time of the roast.
Sugar browning notes achieved through caramelization are malt, nut, and butter. Caramelizing sugar actually reduces the sweetness of the end product, so it’s up to the roaster to decide how they’d like to feature the final product.
Flavor & Aroma
Now that we know our favorite coffees don’t actually have chocolate in them, how do we taste those aromatic compounds? We perceive flavor in a very complex way. This is because your taste buds can only actually understand taste sensations like sweet, sour, bitter, salty, and umami.
The nose and olfactory system come into play when perceiving more specific aromas like chocolate. The olfactory bulb picks up the aromatic compounds present within coffee, and together with the tongue, perceive flavor.
Coffees where sugar browning notes shine
Greater Goods' Pantan Musara has complex flavor compounds of brown sugar and molasses, which support a pleasant earthiness and cranberry acidity in a silky yet heavy body.
Maple syrup sweetness and cinnamon candy are balanced by a sweet orange acidity and a savory black tea in Sparrows' smooth, balanced Burundi Indoto.
Deep and bold with plenty of bittersweet chocolate, caramel, and resinous raisin, Oren’s The Bowery is terrific with or without milk.
Smooth, chocolate sweetness carries throughout Broadsheet’s El Naranjillo, while ripe apricot adds a little depth and dimension to this densely sweet selection.