Gelatin

Gelatin is the aerator most often used in making marshmallow; it is not as light as albumen and yields a firmer, more elastic texture in finished confections. Gelatin not only aerates but also stabilizes confections by forming a gel when it sets; therefore gelatin is ideal for use in higher-moisture candies, like marshmallow, that would not hold their shape with albumen and sugars alone. Gelatin is damaged by excessive heat, so it should not be added to syrups at temperatures over 100°C/212°F. (For more information on gelatin.)