The Physics of the Perfect Coffee Pour

Every day, over a billion cups of coffee are consumed, including French presses, espresso, and cold brewing.

Physicist Arnold Mattissen from the University of Pennsylvania has a bias towards the art of pouring coffee. He manually pours hot water over ground beans, filters it into a pot or mug, and believes that applying fluid dynamics principles could improve the process even further.

Dr. Mathijssen, along with two like-minded students, conducted research on optimizing the pouring method. Their scientifically-backed advice is to pour water in high, slow, and steady streams to maximize extraction and enhance the flavor of the coffee without any additional costs.

Results from a recent survey published in the Journal Physics of Fluids show how the coffee pouring process in the kitchen can lead to new scientific directions in different culinary techniques. This demonstrates how science can improve the art of cooking.

Dr. Mathijssen, who primarily studies biological flow physics, began experimenting with food during the Covid-19 shutdown when he lost access to his lab. This led to exploring the physics involved in various cooking techniques, including pasta stickiness and whipped cream structures. His interest in kitchen physics remains high.

While Dr. Mathijssen has returned to the lab, his passion for kitchen physics continues. The coffee research was inspired by scientists in his group who kept detailed notes on daily coffee brewing experiments in the lab, noting details such as bean origin, extraction time, and flavor profiles.

Graduate student Ernest Park designed a formal experiment using silica gel beads in glass cones to simulate pouring water into coffee grounds from different heights, capturing the dynamics with a high-speed camera.