Cooking has an alternate world, one filled with liquid-nitrogen ice cream, mango caviar and aerated-foam hollandaise sauce. Some call it molecular gastronomy, others call it progressive cooking, and still others know it as modernist cuisine. Chances are you know some of the ingredients used to make these whimsical dishes. Xanthan gum is one such ingredient. Xanthan gum, a corn-sugar derivative, has been used since 1969 to emulsify, stabilize and thicken foods. Xanthan gum thickens sauces, soups and liquids, hot or cold, almost instantly, and helps keep other ingredients, such as herbs, uniformly distributed throughout whatever you add it to.
Weigh the sauce, soup or liquid you want to thicken on a kitchen scale in ounces.
Set the scale to display the weight in grams, if possible. Multiply the weight of the liquid in ounces by 28.3495 to arrive at its weight in grams if your kitchen scale doesn't display grams. Make a note of the weight of the sauce in grams.
Multiply the weight of the sauce in grams by 0.002 if you want to lightly thicken the liquid; multiply the weight by 0.007 if you want to moderately thicken the sauce; multiply the weight by 0.015 if you want to heavily thicken the sauce. For example, if you want to moderately thicken 8 ounces, or 226.796 grams, of liquid, multiply 226.796 by 0.007 to arrive at the amount of xanthan gum needed. Round the amount needed up to the next 10th of a gram.
Weigh the xanthan gum needed to thicken the liquid on a gram scale. Using the example in Step 3 that shows how much xanthan gum you need to moderately thicken 8 ounces of sauce: 226.796 times 0.007 equals 1.58752, rounded up to 1.6. You would weigh 1.6 grams of powdered xanthan gum on a gram scale.
Stir the sauce, soup or liquid you want to thicken after you finish cooking it and sprinkle the powdered xanthan gum over it. Whisk the xanthan gum into the liquid. The liquid will thicken in 20 to 30 seconds.
Keep the sauce warm until needed, season it to taste and serve it or store it in an airtight food-storage container for up to two days in the refrigerator.