Potato Starch Is The Key Ingredient In Kim-Joy's Cookie Cats
Kim-Joy, a British baker who appeared on "Great British Baking Show" back in 2018, has a thing for baked goods with character, and she's so fond of feline-themed ones that in 2023 she published a cookbook called "Bake Me a Cat: 50 Purrfect Recipes for Edible Kitty Cakes, Cookies and More!" complete with an exclamation point to show she's very, very enthusiastic about the subject. One of the cookie recipes depicts the southbound end of a northbound cat complete with seamlessly hidden sprinkles symbolizing ... ugh, we shudder to think what. Another, far more appetizing recipe, is for something she calls "3-D Cookie Cats" which she calls a German-style cookie, although the dough made from all-purpose flour, powdered sugar, and butter is pretty much just good old British shortbread. She also includes what she calls a "secret ingredient," that being potato starch.
Potato starch isn't Kim-Joy's secret alone — other bakers, too, have used it to make their cookies more moist and tender, even if they're not forming them into animal figures. This starch helps to create a texture that Kim-Joy describes as "super tactile" and compares to edible play dough. It does this by replacing part of the flour that would otherwise be used to make dough, thus reducing the overall gluten level. This low-gluten dough can be worked for a lot longer which allows you to perfect (or, as K-J would probably say, "purr-fect") your cookie cat shapes.
How does potato starch stack up to cornstarch?
Kim-Joy's cookie cat dough is very similar to that used in other shortbread or spritz cookie recipes, but many of these call for cornstarch instead of the potato starch she favors. Why, then, does Kim-Joy swear by potato starch instead? Well, as she shares with Epicurious, she once tried cornstarch in her recipe and found the cookies to taste "drier and much less crumbly." Okay, we're not quite sure how they could be both, but potato starch does retain more moisture.
Some home bakers, however, seem to feel that potato starch isn't always the best option for cookies. Cookies made with potato starch not only have a slightly grittier texture than cornstarch ones, but in some cases the ingredient can also give the dough a chalky taste or even lend a potato-like flavor. The best argument in favor of cornstarch, however, may be that it's often more readily available and cheaper than potato starch. What's more, it, too, has a celebrity baker in its corner: Rose Levy Bernbaum, author of "The Cookie Bible," touts cornstarch as her "secret ingredient" for shaped cookies. Just like potato starch, it can replace part of the flour with a gluten-free ingredient, plus, as she tells Epicurious, it also helps break down the gluten in the flour so the cookies don't toughen up as you work the dough.