What is Marshmallow?
Marshmallow is very unique in the world of confections - soft, fluffy, and springy at room temperature turning sticky and gooey when heated. This post will get into some of the science behind what makes marshmallow so special.
What Makes Up Marshmallow?
Marshmallow is made up of the following:
Sugar, typically in the form of sucrose, provides sweetness and structure to the marshmallow. The sugar also increases viscosity of the mixture, which is essential for producing a stable foam.
Corn syrup helps prevent crystallization of the sugar in marshmallows, resulting in a smoother consistency.
Protein - usually albumen from egg whites, gelatin, or a combination of the two - provides stability. In the case of vegan marshmallows, gelling agents that do not contain animal products (such as agar agar) are used.
Water acts as a surface for the protein to gather.
Air provides the volume.
What Gives Marshmallow its Unique Texture?
Marshmallow is considered a foam, a substance formed by trapping gas in a liquid. When marshmallow is being made, air is introduced through whipping. This creates small air bubbles surrounded by a water-based liquid. Protein (usually gelatin) gathers along the surface of the water to create a stable structure trapping the air bubbles. Marshmallow is made up of 50% air, resulting in its signature spongy texture.
What Happens When Marshmallow is Heated?
Photo by Leon Contreras on Unsplash
One of the most popular ways to enjoy marshmallow is toasted, like with s’mores. But what happens while the marshmallow is heated? Toasting a marshmallow over high heat results in a Maillard reaction (a chemical reaction between amino acids and sugar) around the edges, causing it to brown. The air trapped inside also expands as it warms and causes the marshmallow to puff up. Finally, as you continue to heat the marshmallow, the gelatin will melt and release the trapped air. This results in the gooey texture in the inside of a toasted marshmallow.
If you want to melt marshmallow without inducing a Maillard reaction - like when making rice cereal treats or icing - you can do so in a saucepan over low to medium heat, usually with the addition of fat (like butter).
How Do You Make Marshmallow at Home?
The general process for making marshmallows at home is outlined below. Please note, this does not contain ratios or quantities of ingredients, so you will want to find a specific recipe to follow if you want to make them yourself.
Mix corn syrup and sugar in a saucepan and bring to a boil until it reaches about 252 °F. Allow to cool to 100 °F.
While the sugar mixture is cooling, dissolve gelatin in a bowl of warm water.
Once the sugar syrup has cooled to about 100 °F, combine the syrup and dissolved gelatin and whip using a mixer until fluffy and stable.
Spread out the marshmallow on a work surface, allow to cool, and cut into desired shapes.
Has reading this made you hungry? Here are my recipes that use marshmallow
