Candy Making (Hard-Crack Stage, 300 ̊F)
Purpose
This experiment demon-
strates (1) the chemistry
of candy making and
(2) the effect of temperature on the texture of candies.
Materials
• shallow baking pan (8x8x2 inch)
• heavy duty aluminum foil
• oil spray
• 435 grams (about 2 1/8 cups) sugar •1/2 cup light corn syrup
•1/2 cup water
• 2-quart saucepan or 1000 mL beaker
• candy thermometer
• stove (for saucepan) or hot plate (for beaker) • food color
• 1/2 teaspoon oil flavoring
• spatula
Procedure
1. Line an 8x8x2 inch pan with heavy duty alu- minum foil, extending foil over the
edges of the pan. Oil the pan lightly.
2. Combine sugar, corn syrup, and water in a 2-quart
saucepan or a 1000 mL beaker. Place a candy ther- mometer in the pan. The thermometer should not touch the bottom of the pan or beaker. Stir the mixture over high heat until it boils.
3. Reduce heat to medium. Continue cooking over medium heat. Do not stir the mixture while it is cooking. When the syrup reaches 260 ̊F, add food color. Do not stir; boiling action will incorporate color into the syrup. Remove from heat precisely at 300 ̊F. Remove thermometer.
4. Once boiling has stopped, add flavoring. Pour syrup quickly but carefully into prepared pan. (CAUTION: mixture is very hot.) Let it stand for 5 minutes.
5. Using a broad spatula, mark candy surface in 1/2 inch squares. Retrace previous lines and press the spatula deeper each time until you can press the spatula to the bottom of the pan.
6. Cool completely. Use foil to lift candy out of the pan. Bre