Coffee Roasting Basics

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Coffee beans have a long journey from plant to brew. The coffee bean is the pit of a coffee cherry. This pit is separated from the flesh of the cherry in a variety of processes, and then the green bean is prepared for the roasting process. In roasting, our aim is to transform this raw earthy green bean into a darker brown coffee bean, full of aromatic flavor. The roasting process is similar for any of our coffees, but origin of the bean, roasting time, temperature, cooling time, and degassing time can all impact how the coffee flavor develops.  

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1. Drying stage

From the onset, the coffee beans need to be dried. Coffee beans have around 10% humidity, which all needs to be extracted before any roasting occurs. This drying stage will turn the coffee beans from the raw green to a soft yellow as the water within the bean is slowly cooked off. To do this, our beans are placed into a rotating roasting drum at approximately 320⁰F for anywhere up to about 8 minutes. This is enough time to dry out the coffee beans without burning them. Once dried, our beans move onto roasting. 

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2. Roasting stage

The roasting stage is where the magic happens. Nearly all of the flavor, color, and character of the beans is developed during this stage. In the same roasting drum, the temperature now rises to somewhere around 390⁰F-450⁰F for up to 15 minutes. As the temperature heats up, we begin approaching a "first crack". Much like popcorn in a microwave, pressure builds up in the coffee beans as the liquid content turns to gas.  It is at this point that the 'Maillard reaction’ slowly occurs as the temperature rises. The Maillard reaction is when the sugars and amino acids in the coffee bean react together to make hundreds of new color and aroma compounds (melanoids). It's from this reaction that the familiar smell and taste of the coffee bean is created. Different roasts all have slight differences in the temperature, timing, and once the desired roast is achieved, the process needs to be repeated with precision to maintain the same result. The Cooling stage is also critical to the process to maintain a balanced end effect. 

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                  3. Cooling stage

                            When grilling meat, it is always wise to let the meat "rest" after cooking. this allows the juices to                                 settle, and the steak slowly continues to cook from the high temperature. A steak taken off the grill                                  at medium rare, might be medium after resting for a few minutes. In roasting coffee, the same                                      is true, but our desire is the opposite. Once we have achieved the ideal roast, it is critical to                                         reduce the temperature quickly to ensure the beans do not continue to cook. They fall out                                             of a chute from the roasting drum and are immediately hit with a fan to cool them to                                                 room temperature. In less than 5 minutes, all of the roasting needs to have                                                                concluded. At this point, the coffee beans are ready, we allow a short time to degas                                                     the beans and then package fresh for use/purchase.

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                                           3 Different levels of roasting

                                                                  Coffee is segregated into 3 different categories for roast, and the table below will act as a                                                                   general rule of thumb for all of them. 

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          Level of Roast         Acidity                      Body                      Sweetness

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               Light Roast                      Crisp and light acidic taste                 Mellow body                           Very subtle sweetness

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               Medium Roast                 Medium acidity and bitter taste           Medium, balanced body         Some hints of sweetness

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               Dark Roast                      Very bitter taste                                Very full body                        More obvious sweetness

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