Line a baking sheet with heavy-duty aluminum foil. In a heavy pot, mix together sugar, corn syrup, and water. Bring to a boil over medium heat. Add the peanuts. Cook, stirring often, until the peanuts smell parched, about 15 minutes. Add baking soda and stir quickly. The mixture will foam, then turn a golden color. Quickly pour on the prepared baking sheet. When cool, break into pieces.