Pay close attention to the temperature (305 degrees F to 310 degrees F) while heating the ingredients, for if it isn't high enough when you stop the heating, you will wind up with sticky candy, and if it is too high then you will have burnt candy.
Use an instant read thermometer and take frequent temperature readings, especially once the temperature hits 260 degrees F and above, for the rate of temperature increase accelerates as the small amount of residual water is evaporated rapidly during the last few minutes of heating.
Note that this recipe can be used to make other flavors of hard candy simply by substituting the flavor concentrate of your choice for the root beer concentrate. One example is to use Mapleine® concentrate for maple flavored hard candy.
The best type of molds to use when pouring the hot syrupy candy are silicone molds as they are typically safe up to 450 degrees F. They also provide easy non-stick release of the pieces of candy once it has cooled to room temperature. Mold size per individual piece of candy should be relatively small for hard candies, in the range of 2 to 3 milliliters (ml) in volume.
If you don't have an appropriate candy mold you can line an 11" x 17" baking sheet with parchment paper and simply pour the hot syrupy candy onto the parchment paper and let it spread out to a thickness of about 1/8". Dust the surface generously with powdered sugar. Then break up the candy into bite size pieces after it cools to room temperature
Ingredients:
1 1/2 cups of white sugar
3/4 cup of light corn syrup
1/2 cup of water
2 tsp. of root beer concentrate (you might later try experimenting with the amount of the concentrate you use after first using this recommended amount)
food colorings (optional but desirable)
powdered sugar (normally essential for dusting the hard candy once made to keep the pieces from sticking to each other [or to other surfaces])
silicone candy mold(s) (optional)
cellophane candy wrappers (optional)
sealable plastic bags, or an air tight container with parchment paper separation layers to store the hard candy pieces if they are not wrapped
Directions:
Mix the sugar, corn syrup and water in a heavy bottom saucepan. I use a French tin lined very heavy copper saucepan which is ideal when making delicate sauces or candies that might burn inside the saucepan if there is uneven heating of the saucepan bottom, resulting in uneven temperatures in different areas of the bottom of the saucepan. A heavy bottom saucepan avoids that problem by making heat distribution and thus temperature more even on the inside bottom of the saucepan.
Measure out the root beer (or other) concentrate and any food coloring and mix them together in a small container. I recommend using food coloring to enhance candy appearance. For this recipe use four drops of yellow food coloring, three drops of red food coloring and three drops of blue food coloring. That will result in a light brown color to the transparent candy.
Heat the sugar, corn syrup and water mixture slowly on medium heat to between 300 and 310 degrees F. Use an instant read thermometer lightly inserted periodically into the boiling candy mixture in different locations.
When the mixture is at or slightly above 305 degrees F, turn off the heat.
Add the root beer concentrate and the (optional) food coloring and stir to mix well.
Pour the hot syrupy candy into high temperature resistant silicone molds or onto a parchment paper covered baking sheet.
Dust the top surface generously with powdered sugar.
When the candy is cooled to room temperature release the pieces from the mold(s) onto a baking sheet that is covered with 1/4 cup of powdered sugar. Then finish coating the pieces of candy by hand with the powdered sugar.
If you used a parchment paper lined baking sheet instead of a candy mold you must break up the root beer candy into bite size pieces by hand after dusting/coating the top surface with 1/4 cup of powdered sugar. After breaking be sure to coat all the surfaces of the candy pieces by hand with the powdered sugar.
Be sure to have the entire surface of each piece of candy covered with powdered sugar. Store layers of the candy pieces, separated by layers of wax paper or parchment paper, in an air tight container.
Alternatively, if you buy cellophane type candy wrappers (a very good idea ... see Amazon®) you can wrap the candy pieces individually and store them in most any type of air tight container, or even in sealable plastic freezer or sandwich bags.
Finally, note that commercial root beer barrel candy is not dusted in powdered sugar. It is simply wrapped in sealed cellophane. You can approximate that too but only if your final cooking temperature is 310 degrees F to eliminate all residual water from the hard candy. Then you wrap the pieces in cellophane and also use an air tight storage container, for we don't have means to seal the cellophane wrapping at home like what we find with commercial hard candies. Ergo, ambient high humidity can make exposed candy sticky from absorbed moisture, and that is most undesirable.
Enjoy!