Margarine is an imitation butter spread. It is made of hydrogenated oil and water. Margarine can be substituted 1:1 with butter because it is made with the same percentages of oil (80%) and water (20%). It is generally “healthier” than butter in the sense that it has significantly less saturated fat. Although, margarine lacks the taste that butter is able to impart in many recipes.
Margarine is made from partially hydrogenating vegetable oils. Hydrogenation creates a solid fat by decreasing the amount of cis-double bonds (increasing saturated fat levels). These double bonds decrease the amount of van der Waals forces by creating less linear molecular configurations, which reduces the amount of contact between the triglycerides and results in less stability. Hydrogenation removes these elements causing an increase in intermolecular attraction and stability.