Xanthan gum
A thickener made by fermenting sugar with a bacterium. A pinch thickens hot or cold liquids without cooking, holds through acid, salt and freezing, and stays clear — 0.1–0.2% of the liquid's weight gives a jus body or keeps a vinaigrette from splitting; 0.3–0.5% makes it coat a spoon.
neutral · thickens cold · slick if overdone
If you can't find it
Baking and free-from aisles.
Cooked in; much more of it
You lose the cold, clear thickening.
Goes with
vinaigrettefruit puréesaucegluten-free flour
Knowing it
- Where to buy
- Supermarket baking aisles, for gluten-free baking, and modernist suppliers. A small tub lasts years.
- A little history
- Found by a US Department of Agriculture team, and in commercial production by the early 1960s — long an industrial staple before chefs took it up.
- Worth knowing
- Weigh it: a gram in 500g of liquid is already 0.2%. Sprinkle it into the vortex of a running stick blender, or mix it with the sugar or oil first, or it forms clumps. Past about 0.5% sauces turn slick and snotty.