Q. I've been making hard candies at home, but I haven't had a lot of luck giving them a sour flavor. I've tried lemon and orange juice. What are my other options?
Because the juices you've been using are mostly water, they're not going to give your candies the sour kick you want. Your best bet is probably citric acid powder, also called calcium citrate or sour salt.
Citric acid is an organic acid derived from citrus fruit. It's very strong and has a variety of uses. It keeps canned fruit from discoloring and it lends sour flavor to fermented sausages. It can even be used to clean out your dishwasher, so keep that in mind and use it sparingly.
Using citric acid in candy making can be tricky. Like all acids, citric acid will act as a “doctor” when cooked with sugar, preventing crystallization. This process, which breaks down sucrose into fructose and glucose, is critical to candy-making, but must be carefully controlled or your candy will be sticky and brown at a lower temperature.
If you want to use citric acid as a flavor, you should use it sparingly and add it only after the candy has been cooked to the desired stage. Use 1/8 teaspoon citric acid per 2 cups of sugar and work your way up from there. Or you could make a sour coating by dredging your candies in 1/4 teaspoon of citric acid mixed with a cup of sugar.
Citric acid powder can be purchased from the King Arthur Flour Baker's Catalogue at www.kingarthurflour.com; search for sour salt. It costs $5.95 for 3.4 ounces.