Margarine was invented in 1869 by Hippolyte Mège Mouriès, a French food research chemist, in response to Napoleon III's request for a wholesome butter alternative. It is not entirely clear whether the primary aim was the improvement of the life of the working classes or the improvements of the economics in the supply of food to the French army. In a laboratory, Mège Mouriès solidified purified fat, after which the resulting substance was pressed in a thin cloth that formed stearine and discharged oil.
For the new product, Mège Mouriès used margaric acid, a fatty acid component isolated in 1813 by the Frenchman Michel Eugène Chevreul. Analyzing the fatty acids that are the building blocks of fats, he singled out one and named it margaric acid, because of the lustrous pearly drops that reminded him of the Greek word for pearls i.e. margarites or margaron.
In the early days margarine contained two types of fat - a large proportion of animal fat and a small proportion of vegetable fat. Today margarines are mainly composed of vegetable oils.
Like butter, traditional margarine contains 80% fat and 20% water. In the late 1970s the first ‘light’ spreads were developed with only half the fat content, but with the same flavour and texture as the traditional product. Compared to full-fat margarine, lower-fat versions have more and bigger water droplets. To stabilise the water droplets, the water was thickened with starch, just as you would add corn flour to thicken a sauce. Nowadays, consumers are offered spreads with even lower fat levels to fulfil the increasing need for lower-calorie versions.
But, whatever type of margarine you prefer, you can be assured that it is made from vegetable oils.