Cake flour is almost equivalent to pastry flour save one very small distinction, and even then the distinction is questionable. Shock, it’s gluten. Cake flours have a lowered gluten content material of 7-10%. Very similar to pastry flour, it’s finely milled and out there bleached or unbleached. The distinction between cake and pastry flour is trivial, and as you in all probability seen, the gluten content material vary is almost equivalent save for one measly p.c (perhaps).
The ranges in gluten share account for the variations between producers, the wheats they use, and slight variations of their processing. It’s attainable for a cake flour, like King Arthur, and an all-purpose flour, like Bob’s Purple Mill, to have the identical gluten share (on this case 10%).
Be aware that all-purpose isn’t as finely milled, so the distinction between these merchandise may be noticeable, and they aren’t interchangeable. Nevertheless, concerning cake flour and pastry flour—two finely milled, low-gluten flours—even a educated pastry chef can be hard-pressed to note the distinction within the remaining product. Should you want cake flour however your retailer solely has the pastry selection, go forward and purchase it. For all intents and functions, they’re interchangeable.