What is it?
Instant flour is low-protein flour that has been “pregelatanized” so that it can dissolve quickly and smoothly in liquids, regardless of temperature.
It’s usually used to to thicken gravies, sauces, and soups, but it’s also occasionally used in baking. Instant flour’s low protein content discourages the creation of gluten, which makes baked goods, particularly pie crusts, tough
Don’t have it?
In a pinch you can substitute all-purpose, cake, or pastry flour for instant flour. If you’re using instant flour to thicken sauces or gravies, all-purpose flour will work fine, but you’ll probably need to stir more vigorously to keep lumps from forming. If you’re using instant flour in a baking recipe, your best bet is another low-protein flour like pastry or cake flour.