Answer by
bl834 (1317)
For thickening purposes, you can substitute cornstarch, powdered arrowroot, flour, and in some cases even dried potato flakes depending on what you're making. Don't use arrowroot powder if it's a dairy-based sauce (it gets slimy) but it's the best choice for subtly-flavored dishes. Tapioca tends to thicken quicker than the other options so have patience with the subs.