The temperature that you heat the sugar to before pulling it off the heat source, and the additional ingredients that you add.
Approx 285 degrees (F) for toffee, 250 for caramel, and 240 for fudge. The higher the temperature, the more sugar is dissolved in the mixture creating firmer, smoother consistencies.
* 1 pound unsalted butter (preferably Plugrá)
* 1 cup white sugar
* 1 cup brown sugar
* 1 Tbsp. corn syrup
* 1 1/2 to 2 cups raw almonds , chopped finely or ground loosely (with skins on)
* 2 tsp. vanilla extract or 1 vanilla bean (scraped or split so the seeds will come out inside the toffee)
* 1 tsp. salt
* Fleur de sel , for finishing (optional)
* Melted chocolate , for dipping (optional)
Melt butter in a heavy-bottomed pot on stove top. In separate bowl, mix together white sugar, brown sugar and corn syrup, add to melted butter. Add 1/4 cup water. Cook mixture on medium-high heat, stirring with a wooden spoon. Using a candy thermometer—most can clip onto the pot—cook until 240°, stirring hard and fast to make sure nothing is sticking to the pan and your toffee doesn't burn. At 240°, add the almonds. At 260°, lower the heat and finish cooking until your candy thermometer reads 300° and reaches the soft ball stage. It should take about 15 to 20 minutes total to reach the 300° mark. The mixture should be a beautiful, bubbly, golden brown color. At 300°, turn off heat immediately.
Add vanilla (if adding vanilla beans, you must fish them out when you pour the toffee before it cools) and add the salt. Stir quickly. Pour the mixture out onto a marble slab that has been greased with butter, or grease 2 rimmed baking sheets (10" x 15" or around that size). Smooth out the toffee to 1/4-inch thickness. After about 5 to 10 minutes, you can score the toffee with a knife in order to break it up later. Using hot water and wiping the knife clean after every slice can help in scoring the toffee. You may now let the mixture cool. When cool, you can sprinkle with a dash of fleur de sel (French sea salt), break them up and wrap them in cellophane or an airtight container to maintain the freshness.
1 qt. heavy cream
1 lb. butter
1 lb. brown sugar
2 1/3 c. white sugar
1 pt. dark Karo
1/2 tsp. salt
1 tsp. vanilla
Mix sugars together and add Karo. Cut in butter and 1/2 of cream. Let come to a boil. As it stars to boil, add rest of cream. Cook approximately 1 1/2 hours or until soft ball stage (no more than 250 degrees F), stirring constantly. When done, remove from heat. Add vanilla. Pour in buttered pan and place in refrigerator until firm or overnight. Cut and wrap in wax paper. While cooking, try some on ice cream.
For Chocolate Fudge:
1 1/2 c Milk
4 oz Unsweetened chocolate (sqs)
4 c Sugar
3 tb Light corn syrup
1/4 ts Salt
3 tb Butter or margarine
1 1/2 ts Vanilla
Combine milk and chocolate in medium-size heavy saucepan; cook over low heat until chocolate is melted. Add sugar, corn syrup and salt and cook, stirring constantly, to boiling.
Cook, without stirring to 234F on a candy thermometer. (A teaspoonful of syrup will form a soft ball when dropped into cold water.) Remove from heat at once. Add vanilla and butter or margarine, but do not stir in.
Cool mixture in pan to 110F, or until lukewarm; beat with wooden spoon until mixture thickens and begins to lose its gloss. (This will take about 15 minutes.)
Spread in a buttered 8x8x2" pan. Let stand until set and cool; cut into squares. Makes about 2 pounds.