Chestnuts are an unusual fruit, rich in complex carbohydrates (starch) as cereals. They are a good source of fiber, potassium and B vitamins, especially B1 and B6. Cooking converts the starch into simple sugars, which give the characteristic sweetness. For hundreds of years have chestnuts rappersentato the main food source of the populations of the Apennines during the autumn and winter. The marmalade is made with chestnut puree. Given the low acidity is a very perishable product, and keep well requires a high percentage of sugars, usually 60%. The chestnut jam is very sweet so a product can be worn alone with cottage cheese or yoghurt, or to prepare desserts, or as a filling for crepes.