Ingredient
Xanthan gum
Why bottled dressings and sauces use xanthan gum, what it actually does, and when a home cook can skip it.
What it is
Xanthan gum is a fermented polysaccharide used in tiny amounts — often 0.1–0.5% — to thicken and keep water and oil from separating. On a label it appears near the end because very little is required.
Why packaged food uses it
A bottle of ranch must pour the same in July and January, after a truck ride. Xanthan gives cling on lettuce and stops a watery layer from forming. It is a shelf-stability tool more than a flavor.
Do you need it at home?
Usually no. A dressing you will eat this week can rely on egg yolk, mustard, or simply shaking before each use. If you want bottle-like cling, a pinch (start under 1/8 teaspoon per cup) mixed into the dry spices first will disperse more evenly than dumping it into liquid.
When there is no good substitute
If the product is a fat-free dressing that is still thick, xanthan (or another gum) is doing almost all of the body. Flour or cornstarch will taste pasty in a cold dressing. In that case Recipe Solver will say the homemade version will be thinner, or it will use a dairy or oil base instead of pretending a gum-free copy is identical.
Scan a packaged food
Recipe Solver rebuilds from the package — not a generic recipe from the name.