Use and Substitutes
Tapioca starch is industrially extracted from cassava; making it at home is unnecessarily involved. The best substitute depends on the use case.
For thickening
Replace 10 g tapioca starch with 10 g corn or potato starch. Always mix with cold liquid first. Don't boil potato starch for long, or it loses its binding power.
For stretchy gluten-free doughs
Replace 100 g tapioca starch with 70 g potato starch plus 30 g cornstarch. The result will be a little less stretchy, but stays light and crisp.
For cheese-pull or chewy texture
Tapioca is hard to fully replace; potato starch comes closest. Start with 80% of the stated amount and only increase if needed.
Basic rule
Never sprinkle starch directly into hot liquid — it clumps.