Line a 10x12-inch cookie sheet with heavy-duty aluminum foil. In a heavy pot, mix together the 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 the baking soda and stir quickly. The mixture will foam, then turn a golden color. Quickly pour on the foil-lined cookie sheet. When cool, break into pieces.