Muesli and granola are virtually indistinguishable on the grocery store shelf. Despite sharing many common ingredients and remarkably similar histories, however, the two oat-based cereals are actually quite different.
A Swiss physician developed muesli in the early 1900s. The original dish was made by combining a small amount of raw, rolled oats with an equal amount of ground almonds, a bit of lemon juice, some condensed milk and a large, freshly grated apple. Modern muesli is typically made up of raw oats, nuts, seeds and dried fruit. The dry mixture is traditionally soaked in milk and consumed raw.
Granola was developed in the United States in the 1890s. Although it usually contains oats along with nuts, seeds and dried fruit, granola can also be made from barley, rye or any other suitable grain. The mixture is tossed with canola oil, butter or some other fat, sweetened with honey or maple syrup and baked until the ingredients form crunchy clusters. Granola is often served with milk or yogurt.