Combine sugar, corn syrup, and water in a heavy 4–quart pan.

Stir over heat only until the sugar is dissolved.

Cook until mixture reaches the softball stage (236°).

Add the peanuts.

Cook until mixture becomes golden brown and reaches the hardcrack stage (290°), stirring occasionally.

Remove from heat and stir in soda thoroughly.

Pour at once onto buttered cookie sheet.

Spread to a thin layer.

Cool, then break into pieces.