Whipped cream is cream that is whipped by a whisk or mixer until it is light and fluffy. Whipped cream is often sweetened and sometimes flavored with vanilla. Whipped cream is often called Chantilly cream or crème Chantilly (pronounced [kʁɛm ʃɑ̃tiji]). Whipped cream is an aerated colloid produced when air is incorporated into cream containing at least 35% fat. During whipping, partially coalesced fat molecules create a stabilized network which traps air bubbles. The resulting colloid is roughly double the volume of the original cream. If, however, the whipping is continued, the fat droplets will stick together destroying the colloid and forming butter. Lower-fat cream (or milk) does not whip well, while higher-fat cream produces a more stable foam. Cream is usually whipped with a whisk, an electric or hand mixer, or a food processor. Results are best when the equipment and ingredients are cold. Whipped cream is often flavored with sugar, vanilla, coffee, chocolate, orange, and so on. Many 19th-century recipes recommend adding gum tragacanth to stabilize whipped cream; a few include whipped egg whites. Various other substances, including gelatin and diphosphate (E450), are used in commercial stabilizers. Whipped cream may also be made in a whipping siphon, typically using nitrous oxide as the gas, as carbon dioxide tends to give a sour taste.[10] The siphon may have replaceable cartridges or be sold as a pre-pressurized retail package. The gas dissolves in the butterfat under pressure, and when the pressure is released, produces bubbles and thus whipped cream.