Start to Finish: 20 to 45 minutes
Back in the day, the only place to find an achingly sweet, tooth-breakingly hard bona fide candy apple was at a circus, carnival or town fair. These days, you can buy an accurate candy thermometer in your grocery store's utensil aisle, and fresh apples of one type or another are available all year 'round.
Line a baking sheet with aluminum foil or wax paper. Spray it with a light coating of nonstick cooking spray to keep the candy apples from sticking as they cool. You can also use a bit of butter or a neutral oil such as canola or vegetable oil.
Wash your apples and dry them completely with paper towels or a lint-free dish towel. Any type of round apple will do, though Granny Smith apples offer a light tartness to counteract the sweetness of the hard candy coating.
Red Delicious apples can be oddly shaped, so it's best to save them for another use.
Twist the stems off, but do not cut or peel the apples.
Insert candy apple sticks into the stem ends of the apples. Do not use regular skewers, because they may not be able to handle the weight of the coated apple.
Mix the sugar, corn syrup and water together in a deep saucepan. The proportions do not have to be exact, but you will need approximately 1/2 to 1 cup of corn syrup and 1 cup of water for every 3 cups of sugar. Add red food coloring to get the the classic glossy red coating.
Heat the mixture over medium-high heat, stirring if you feel the need to, though this is not strictly necessary. Insert your candy thermometer after approximately 20 minutes. Your mixture should be between 290 degrees Fahrenheit and 302 F, which is called the hard crack stage.
Remove the pot from the heat and tilt it carefully to one side. Swirl your skewered apples one at a time in the deepest part of the hot mixture. Set them with their skewers sticking straight up on your lined and oiled baking sheet.
Let the candy apples cool at room temperature for one hour, or in the refrigerator for 30 to 45 minutes, and enjoy.
Add cinnamon oil or vanilla extract to your candy mixture to take the flavor up a notch.
For caramel apples, melt soft caramels and use them to coat your apples. Caramels contain natural paraffins that help them re-harden when they cool.
Roll your candy apples in finely shredded coconut, chopped nuts or crushed hard candies for an extra bit of flavor and a beautiful presentation.
Place your pot on a burner over very low heat if you're making a double batch, to keep the coating from hardening before you get all of the apples dipped.
Do not let the hot sugar mixture splash or drip on your skin when you are coating the apples, because it will adhere to yor skin, making the burn worse.