In a large heavy saucepan, combine sugar, corn syrup and water. Bring to a boil over medium heat, stirring occasionally. Cover and cook for 3 minutes or until sugar is dissolved. Uncover; cook on medium-high heat, without stirring, until a candy thermometer reads 300° (hard-crack stage).
Remove from the heat; stir in extract and food coloring (if using anise oil, keep face away from mixture as the aroma will be very strong). Pour into a buttered 13-in. x 9-in. pan. When cooled slightly but not hardened, cut into 1-in. squares. Cool completely. Store in an airtight container.
We recommend that you test your candy thermometer before each use by bringing water to a boil; the thermometer should read 212°. Adjust your recipe temperature up or down based on your test.