Study Inspects How Roasting Affects The Perfect Brew – CoffeeTalk

A recent study by Zachary Lindsey, an assistant professor of physics at Georgia’s Berry College, has found that the perfect cup of coffee is a blend of factors that balance flavor and zing. The researchers analyzed the relationship between coffee beans’ chemical and physical attributes through various roasting and brewing scenarios, focusing on natural and washed processed Ethiopian beans. They examined five varieties of roasts across brew times of one, two, and ten minutes using a machine with a 15:1 water-to-coffee ratio.

The results, published in the journal Scientific Reports, offer a detailed look at 30 unique coffee combinations on microscopic and chemical levels. High-performance liquid chromatography (HPLC) was used to assess the molecular makeup of soluble compounds like caffeine and chlorogenic acids, while scanning electron microscopy (SEM) imaged whole and ground beans to provide observers with a close look at porosity and grain size.

Refractometry, the measurement of light bending, was used to learn brewing extraction yields. The study found that attributes such as caffeine content are the result of intricate relationships between how coffee is roasted and how well its organic compounds can dissolve into water. Light and medium roasts on average measured higher levels than darker variants across the roasting spectrum samples, due to the amount of caffeine that is lost during the process. Darker roasts, however, maintained higher caffeine levels than lighter roasts when porosity and extraction yields were uniform across all varieties.

While the ideal coffee brew is ultimately a matter of personal taste or access to ultrasonic frequencies, Lindsey suggests a medium roast blend for the most caffeine per cup.

Read More @ Popular Science