For steam peeling to take place it is necessary that the thermal treatment satisfies the following conditions: (a) that the cooking value reaches at least 17 s at 100°C, what would thermally weaken in a sufficient way the cellular structure, (b) that the temperature reaches at least 100°C, what would let that the internal vapor pressure developed during the peeling process be sufficient in the decompression stage to produce the mechanical failure of the thermally weaken cells; then the skin and part of the potato pulp up to where the peeling front advanced would be easily pulled off by the pressurized water applied after peeling.