In a medium saucepan, mix together the sugar and cornstarch, then stir in the corn syrup, water, glycerin, and salt.
Mix well over medium heat. Once the mixture begins to bubble, stop stirring and insert your candy thermometer.
Brush the sides of the pot with a wet pastry brush if you see sugar crystals.
Continue to cook until it reaches 254 degrees. Swiftly remove from heat and add your baking soda, flavoring, and food coloring.
Mix to combine. To make the lemon pound cake flavor I did, you need a scant ½ teaspoon lemon extract, ½ teaspoon butter extract, and ¼ teaspoon vanilla extract.
Pour the sugar mixture on your greased slab or pan and wait until it is cool enough to touch. Roughly 5 - 10 minutes. To speed the process, you can use a bench scraper to fold the sugar mixture over itself and also begin letting air into the mixture.
Once it is cool, lightly grease your hands if desired and begin pulling, folding the candy over itself, and pulling more. You need to pull the taffy at a vigorous pace for about 10 - 15 minutes.
Pull the taffy into a long, thin rope and use your kitchen scissors or a knife to cut out your pieces. Wrap them individually in wax paper.