Method for preparing deep-frozen vegetable pieces, preferably potato pieces such as french fries, comprising of bringing the vegetable pieces into brief contact with an inert substance which has a temperature which is sufficiently low and for a period of time which is sufficiently long to impart to the outer layer of the vegetable pieces a temperature which is 0° C.; slowly freezing the vegetable pieces until the pieces are fully deep-frozen by bringing the vegetable pieces into contact with air.