Vegetable oil and U.S. farmers started planting large areas that spring. Canola oil is lower in saturated fats, and higher in monounsaturates and is a better source of omega-3 fats than other popular oils. Canola is very thin (unlike corn oil) and flavorless (unlike olive oil), so it largely succeeds by displacing soy oil, just as soy oil largely succeeded by displacing cottonseed oil. A large quantity of used vegetable oil is produced and recycled, mainly from industrial deep fryers in potato processing plants, snack food factories and fast food restaurants. Recycled oil has numerous uses, including use as a direct fuel,
Vegetable oil the margarine does not melt in warm rooms, yet it needs to be completely liquid at 37 °C (98 °F), so that it doesn't leave a "lardy" taste in the mouth. Hardening vegetable oil is done by raising a blend of vegetable oil and a catalyst in near-vacuum to very high temperatures, and introducing hydrogen. This causes the carbon atoms of the oil to break double-bonds with other carbons, each carbon forming a new single-bond with a hydrogen atom. Adding these hydrogen atoms to the oil makes it more solid, raises the smoke point, and makes the oil more stable.