To blanch means to lightly cook raw ingredients for varying amounts of time in boiling water, with or without salt and vinegar. The ingredients are then refreshed in cold water. It also means to cover with boiling water for a few seconds to facilitate peeling. Tomatoes, peaches, almonds and pistachios can be treated in this way with no damage to the flesh. Blanching is increasingly becoming synonymous with parboiling, as in preparing green vegetables for the freezer.