White Rice Flour: why 142 g per cup is wrong
King Arthur Baking (Ingredient Weight Chart) publishes 142 g per US cup of white rice flour. This site rejects that figure and publishes 160 g instead, from Bob's Red Mill Flour Weight Chart (density 0.6763 g/mL, matching the composition of the substance). The reason:
Eleven percent below the four-way convergence of Bob's Red Mill's own chart, two USDA Branded Foods entries for Bob's products, and USDA composition data — all landing at approximately 160 g/cup. Also fails internal consistency: KA lists brown rice flour at 128 g/cup, only 10 percent below their white figure of 142, but producer and USDA data show brown rice flour typically 15-25 percent below white due to the bran-heavy particles packing less efficiently. KA's white figure is compressed toward brown in a way inconsistent with the physical difference between endosperm-only and bran-and-germ-inclusive rice flours.
The arithmetic
| Source | 1 cup | Density | Status |
|---|---|---|---|
| King Arthur Baking (Ingredient Weight Chart) | 142 g | 0.6002 g/mL | Rejected on physics |
| Bob's Red Mill Flour Weight Chart | 160 g | 0.6763 g/mL | Published here |
The published figure and its sources
The full sourcing for white rice flour, 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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