Marshmallow Creme: why 128 g per cup is wrong
King Arthur Baking Ingredient Weight Chart publishes 128 g (4.5 oz) per US cup of marshmallow creme. This site rejects that figure. The sources it accepts put a cup at 96–104 g (3.4–3.7 oz), and it publishes that range rather than a single figure. The reason:
Marshmallow creme is corn syrup and sugar whipped with egg white into a foam that is mostly air. Fluff's maker, Durkee-Mower, says a cup of Fluff weighs slightly more than 3 oz, and every jar label weighs 2 tablespoons at 12 or 13 g, 0.41-0.44 g/mL, 96-104 g per cup. 128 g per cup is 0.54 g/mL, a quarter to a third heavier than the creme as sold. A level cup only gets there if the foam is pressed down until part of it collapses. King Arthur's own row for store-bought marshmallow spread gives a different figure again, 123 g.
The arithmetic
| Source | 1 cup | Density | Status |
|---|---|---|---|
| King Arthur Baking Ingredient Weight Chart | 128 g4.5 oz | 0.541 g/mL | Rejected on physics |
| Accepted sources (4) | 96–104 g3.4–3.7 oz | 0.4058–0.4396 g/mL | Published as a range |
The published figure and its sources
The full sourcing for marshmallow creme, including every accepted and rejected figure, the state or filling method behind each, and the physics or standards reasoning applied, is on the ingredient page.
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