<<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
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