How Restaurants Achieve Perfectly Thickened Sauces

It seems that every time you dine out, the food is just a little better than it is when you make it yourself. Restaurants have all kinds of food prep tricks and cooking techniques that aren't often incorporated into home-cooked meals. At home, you likely use a roux to thicken up sauces, but in a restaurant, if the chef isn't using a roux or slurry, they're probably using xanthan gum instead.

No, xanthan gum is nothing like chewing gum. It's actually a powdered substance that acts as a thickening agent; you stir it into sauces that are too thin, and it gets them to the right texture without altering their taste. You'll likely find it on the ingredients list of many packaged products, and it can even be used as a secret ingredient in frozen cocktails. In food, very little xanthan gum is required because of how powerful it is, so often less than a teaspoon will do. Essentially, it's a combination of sugar and Xanthomonas campestris, a type of bacteria commonly found on certain plants like broccoli and cabbage. The bacteria ferment the sugar, then alcohol is added, turning the substance into a solid. It's then ground into powder for use in food. To thicken a sauce, you can blend in small quantities until it reaches the desired thickness.

If you want to use it at home, you can purchase xanthan gum from a reputable brand, like the Modernist Pantry Xantham Gum. (It is also available near the flour in some grocery stores.) You need very little xanthan gum to get the best results; use only about one-eighth of a teaspoon for every cup of liquid. Don't try to whisk the gum in by hand. Similarly to a roux or slurry, lumps form quickly, and unless the liquid is always in constant motion for the entire combining process, you'll end up with clumpy sauce. For the smoothest texture, add the powder and sauce to a blender, then blend the xanthan gum into the sauce. The reaction will happen almost immediately, and you can add a little more powder as needed.

Xanthan gum is popular in gluten-free cooking and baking because it does not contain gluten; it's an easy way to thicken up a gluten-free sauce because it takes the place of a traditional roux.