Why This Recipe Works
To make homemade marshmallows, we heat a mixture of water, sugar, and corn syrup and beat it with unflavored gelatin until the mixture transforms from a translucent liquid into a white, fluffy goo. We found that when the mixture is thick enough to coat the whisk of a stand mixer, it will set up firm. We spread the mixture into a pan (lined with greased foil for easy removal), let it set up, and cut it into cubes. We found that the gelatin is key for structure. Without it, you’d end up with something like marshmallow crème.