Does cornstarch contain gluten?

Ask Peggy

Ask Peggy

DEAR PEGGY: I have celiac disease, and I wonder if I can substitute cornstarch in recipes that call for flour. —H.P., Clifton Park, New York

It's now estimated that one in every 133 Americans has celiac disease, an immune response to the gluten found in wheat, barley and rye. For celiac sufferers, eating gluten-filled foods can damage intestines and affect nutrient absorption.

Corn doesn't contain gluten, so you can substitute cornstarch in sauces and soups that use flour as a thickener. But there are a few things to remember:

  • Cornstarch is a more powerful thickener than flour, so you'll need less. Start with half as much cornstarch for the flour listed in the recipe.
  • Cornstarch breaks down faster than flour, so it must be added at the end of cooking. Combine cornstarch with cold water until smooth and stir into the sauce or soup. Bring to a boil; cook and stir until thickened.
  • Sauces and soups thickened with cornstarch that are chilled and reheated may not maintain the same consistency as when they're fresh.
  • The protein in flour gives breads, cakes and baked goods their structure. Since cornstarch lacks this protein, it can't be used as a substitute in baked goods. Experiment with rice, tapioca and buckwheat flour and fine cornmeal instead.
  • Many new gluten-free foods can be found on grocery store shelves. Look for gluten-free cake, bread and cookie mixes as well as the alternative products mentioned above.