Roux Roux Roux () is flour and fat cooked together and used to thicken sauces. Roux is typically made from equal parts of flour and fat by weight. The flour is added to the melted fat or oil on the stove top, blended until smooth, and cooked to the desired level of brownness. Butter, vegetable oils, bacon drippings or lard are commonly used fats. Roux is used as a thickening agent for gravy, sauces, soups and stews. It provides the base for a dish, and other ingredients are added after the roux is complete. The fat is most often butter in
Flour imported from Japan and the Japanese name Zenryufun(全粒粉) is used. It is possible to determine ash content from some US manufacturers. However, US measurements are based on wheat with a 14% moisture content. Thus, a US flour with 0.48% ash would approximate a French Type 55. Other measurable properties of flour as used in baking can be determined using a variety of specialized instruments, such as the farinograph. Flour dust suspended in air is explosive—as is any mixture of a finely powdered flammable substance with air ("see" dust explosion). Some devastating explosions have occurred at flour mills, including an explosion