The science behind a simple cup of coffee is brewing curiosity across metro Atlanta as the Atlanta Science Festival returns with hundreds of hands-on events.

CBS News Atlanta stopped by Opo Coffee in Decatur, where owner Jonathan Pascual is helping festivalgoers learn how science plays a role in making the perfect cup of coffee.

Pascual demonstrated several tools used by coffee professionals, including a coffee siphon, a brewing method that uses heat and pressure, and a coffee refractometer, a device that measures how strong a cup of coffee is by analyzing how light refracts through the liquid.

“That tells us if the sample has a certain percentage of coffee solids in the water,” Pascual explained. “Then it tells us how strong it is.”

According to Pascual, an ideal cup of coffee typically measures about 1.4% total dissolved coffee solids, which helps baristas determine whether the brew is properly balanced.

Festival participants will also learn about the chemistry behind milk used in lattes and cappuccinos, including how proteins and fats react when milk is steamed to create foam and texture.

Opo Coffee has partnered with the Atlanta Science Festival for the past three years, offering demonstrations that connect everyday routines, like brewing coffee, with science.

The Atlanta Science Festival, presented by Delta Air Lines, runs March 7 through March 21 and features about 150 interactive events at more than 80 locations across metro Atlanta.

The celebration culminates with the Exploration Expo in Piedmont Park on March 21, where families can explore hands-on exhibits ranging from robotics and engineering to biology and space science.

More information about festival events is available at AtlantaScienceFestival.org.