The rind of Brie cheese is made of edible white mold, specifically a type of fungus called Penicillium camemberti (also known as Penicillium candidum). This mold is intentionally added during the cheese-making process and forms a soft, white, bloomy rind that helps ripen the cheese from the outside in, giving Brie its creamy texture and characteristic flavor. So yes, it's fungus—but the delicious, friendly kind! And it's totally safe (and yummy) to eat.