Do random questions about food often cross your mind every now and then? Well, what about this question, why are brownie skins so dang shiny?

Good news, Youtuber and chef Adam Ragusea has given us an answer to this thought. The science behind the gloss on a brownie skin.

Ragusea is known for “culinary investigations” and experiments. Ragusea speaks with a Harvard professor, Dr. Pia Sörensen, to find out the science behind the shininess. Sörensen, a PhD in Chemical Engineering and Applied Materials, hypothesizes that the thin layer of brownie skin forms from a foamy layer of air bubbles suspended in relatively starch-starved liquid batter. The idea being that the starch settles into the brownie’s guts, leaving a wafer-thin meringue on top.

Watch video below.

So, what did you do at work today? pic.twitter.com/VQzjh2lugn

— Adam Ragusea (@aragusea) January 20, 2021

So, the verdict? Ragusea finally lands on the skin’s smoothness as the reason for its shine. He notes, for example, that the bottom of brownies are often pretty shiny too; as well as smooth, from being pressed up against a pan. And because the skin is so smooth, light is able to reflect off of it directly; as opposed to a rough surface, which scatters the light.

The more you know.

H/T| Nerdist.com
Photo| iStock