To reduce the dangerousness of mixing foreign materials therein and produce a beam jam, excellent in aromatic flavor and capable of retaining taste close to the natural one by placing a fruit, etc., of a plant in water, etc., heating the fruit, boiling down the fruit, then filtering the soup and adding an adequate amount of the resultant soup stock to a raw material for a bean jam or a custard cream.

A fruit, a flower, a leaf, a root, etc., of a plant such as a citron, a Ume (Japanese apricot), a cherry, a beefsteak plant, a tangerine orange, a mushroom, a carrot, a sesame or a sea tangle or an animal skin, a meat, a bone, etc., such as a fish, a shellfish or a crab is placed in water containing a small amount of liquors, spirit of wine, etc., mixed therein, heated, boiled down and then removed from the fruit, flower, leaf, root of the plant or the animal skin, meat, bone, etc., with a filter. An adequate amount of the resultant soup stock is subsequently added to a raw material for a bean jam or a custard cream and the prepared mixture is used as mixing water to afford the bean jam or custard cream.