<<Disclaimer: Verify this information before applying it to your situation.>> In addition to supermarkets that carry Jewish foods, you will usually find potato starch at Oriental markets. If there are any Japanese markets in your area, they'll definitely have it. Although they're usually marked in English as well, potato starch is called "katakuriko" in Japanese. I have found several different brands of Japanese potato starch, varying from about $2 to $4.50 per cup and 1/2 (12 ounces?). For my uses, I haven't noticed a difference between them, although the expensive stuff is in more humidity-resistant packaging and I would guess would stay fresh longer. I don't know if there is a noticeable difference between the price grades when used for tempura (Japanese fritters) as I rarely make it. As for potato flour, I have only found it at health food stores. Best wishes, Kirsten Klinghammer [log in to unmask]