The Chemistry of Coffee
The search for the perfect coffee starts with a single bean. This bean’s journey and the environments it endures can have an effect on the quality of the coffee. Finding the best coffee is more of a science than an art; along its path to your cup, chemistry has a large impact on just how good your morning joe tastes.
Let’s take an adventure with the coffee bean, from the soil it’s grown in to the mug you drink it out of:
IT ALL STARTS WITH THE BEAN
Selecting great beans puts coffee on the path to success. The best beans are ones that have benefited from decades of natural selection and breeding for the best qualities. Just as scientists scour the Amazon for plants with medicinal qualities, they have done the same with coffee to find ones with the most benefits. Some of these positive attributes include high levels of antioxidants and anti-inflammatory substances. Just as antioxidant levels are often used to measure the quality of a fruit, they are also an excellent litmus test for taste and quality in coffee beans. Beans that rate at the top of taste reviews are also those that achieve big health benefits. Research has shown that there is even a correlation between superior taste and beneficial health qualities. In essence, the better the bean is for you, the better it tastes in the end.
LOCATION, LOCATION, LOCATION
Coffee beans can be artificially engineered to contain high levels of antioxidants, but isn’t it even better if they occur naturally? Luckily, environment can have a huge effect on the antioxidants levels in a coffee bean. Coffee beans that are forced to protect themselves from harsh environments end up being the most robust. Beans develop antioxidants and anti-inflammatory substances as defenses against the elements, making them better tasting and healthier. The best beans are those that are grown at high altitudes and close to the equator, where they’ve been challenged to form the strongest defenses against harsh ultraviolet rays.
Geology also has a great deal to do with a coffee bean’s success. Coffee trees require a large supply of nutrients, which are delivered through soils formed from broken-down rocks. Soil makeup also affects a coffee’s flavor profile—though the causes of flavor are so complicated, that two beans from the same farm may even taste different. Because coffee trees require nutrient-rich, fertile soils, the ideal types are volcanic earth or deep sandy loam, which are relatively untouched by the elements (EGU).
ON THE WAY TO YOUR KITCHEN
After coffee beans are washed and dried, they are sent to be roasted. The way in which they are packed can deteriorate or preserve the bean, so this is a crucial step in maintaining the bean’s quality. Coffee beans are very sensitive to moisture and can become tainted by the aromas of neighboring goods. Still, unroasted coffee beans are typically transported in well-ventilated woven bags to allow for air circulation. Once the coffee beans are roasted, they are transported in airtight containers to preserve the aromas and other qualities that roasting is designed to illicit.
Coffee beans are roasted in order produce flavor and aroma. Prior to roasting, beans are small and green with no aroma, but after, they inflate and gain their iconic dark brown color and strong aroma (The Atlantic). Once the beans reach an internal temperature of about 400 degrees Fahrenheit, they begin this transformation, releasing their signature flavors and aromas and turning a dark brown. Various aspects of roasting—like proprietary temperature, speed of temperature increase, and roast duration—vary the roast profile and thus change the roasted bean product. Roasting is typically performed in the importing country to reach the consumer more quickly because coffee is best right after it’s been roasted.
After roasting, the beans are ground to make them usable for different brewing techniques. Different methods require different grits; for example, the finer the grind, the more quickly the coffee should be used. That’s why coffee ground for espresso is much more fine than coffee ground for a drip machine (NCA).
Once the coffee has made its way to your kitchen, it’s finally time to brew a cup. Brewing extracts caffeine, antioxidants, and key flavor compounds in order to impart great taste and health benefits. The recipe for a great extraction relies on temperature and time. Temperature can vary from 170 degrees Fahrenheit to the boiling point. The higher the temperature, the greater the extraction. Time is also a key in extraction; caffeine is extracted in the first few minutes of brewing, and then fats and aromas follow. Acids are extracted last, so brewing needs to end before these bitter ingredients make their way into your cup. Finding an ideal temperature/time combination for each individual coffee creates the best possible cup, with ideal taste and health benefits.
Finally, serve with a porcelain or ceramic mug to retain the coffee’s heat. Enjoy!