Put about three tablespoons of baking soda into a couple of cups of boiling water in a saucepan. Add your unpeeled hazelnuts to the boiling liquid and let them go for about three minutes. The water will turn black and look dreadful Take out one hazelnut to test in cold water. The skin should slide right off. If it does, dump the whole mess into a colander in the sink and run cold water on the nuts. Rub them and the skins will come right off. I saw it with my own two eyes.