What jus means
Jus is the French word for juice, and in cooking it refers to a thin, flavourful sauce made from the natural juices of roasted or cooked meat. When meat is roasted, it releases juices that collect and caramelise in the bottom of the tin. To make a jus, the meat is lifted out to rest, most of the fat is poured away, and the tin is deglazed with a little wine, water or stock, scraping up the browned bits, which are full of flavour. The liquid is simmered, often with more stock, and reduced until its flavour is concentrated and it has a light, glossy body.
The resting juices from the meat are added, and the jus is strained and seasoned. Unlike British gravy, a jus is not thickened with flour, so it remains thin and clear, letting the taste of the meat come through. In restaurants, jus is often made from well-reduced brown stocks, roasted bones and vegetables, which give a deep, rich result, and it is served in small amounts around the meat. Jus lié is a version lightly thickened with starch.
The phrase au jus means served with its natural juices. You will see jus on restaurant menus and in recipes for roast beef, lamb, pork and chicken.