Marshmallows are made with sweeteners and emulsifiers. Sweeteners such as corn syrup, sugar or powdered marshmallow root are mixed with corn starch, egg whites or gelatin.
First, the sugar is dissolved in water and brought to the “hard ball” stage of candy, which is around 240 degrees Fahrenheit. Then, gelatin is added, and the liquid is whisked into beaten egg whites. The hot liquid must be added slowly and whisked continually to not cook the egg whites. Third, the mixture needs to cool on a greased container. Finally, the marshmallows can be cut with an oiled knife and stored in an airtight container for up to two weeks.