How marshmallows are made
A marshmallow is about half air, whipped into hot sugar syrup and trapped by gelatin before it can escape.
- stations
- 6
- things upstream
- 12
- raw sources
- 7
- steps from the ground
- 3
The short version
Marshmallows are a foam. Sugar, corn syrup and gelatin are cooked into a syrup, cooled a little, then whipped with compressed air until the mix doubles in volume. The foam is squeezed out as a long rope, cooled until the gelatin sets, chopped into pieces and dusted with starch so the pieces do not stick.
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Cook gelatin into syrup
Corn syrup, sugar and water are cooked with the gelatin in a fast cooker. Because the syrup spends so little time hot, hardly any gelatin breaks down. A mostly-corn-syrup recipe stays smooth because the mix of sugars resists forming crystals.
112–116 °C in 20–30 minutes
Goes in -
Whip in compressed air
The warm syrup passes through an aerator, where pins on a spinning cylinder pass between pins fixed to the wall. Compressed air is injected and the shearing breaks it into countless tiny bubbles.
about 50% air
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Squeeze out a rope
A round nozzle lets the foam out of the aerator as a continuous rope. The temperature must stay just above the gelatin's melting point, or the rope slumps and the marshmallows come out oval.
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Cool until it sets
The rope travels on a belt through a cooling stretch. As the gelatin cools it forms a net of tangled protein chains that locks the bubbles in place.
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Chop to size
Blades slice the set rope into equal pieces. Other lines deposit the foam onto belts for shaped candies, or into starch trays in a mogul.
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Dust with starch
Cornstarch is tumbled over the pieces to stop them sticking to each other. They are then sealed in bags.
Goes in
Worth repeating
- The first marshmallows were made by boiling pieces of marsh-mallow root pulp with honey until thick, which is where the candy gets its name.
- Alex Doumak patented the extrusion process for marshmallows in 1956.
- Gelatin melts at around 95 °F (35 °C), just below body temperature, which gives marshmallows their melt-in-the-mouth feel.
Back to the ground
Follow every input upstream and marshmallow starts as these 7 raw sources.
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Sources
Cite this page: "How marshmallows are made." Assembly Line, 2026-11-03. https://assemblyline.org/make/marshmallow