Cooking-oil spray
1 1/3 cups citrus juice (pasteurized orange or pink grapefruit; or fresh blood orange, lime, or lemon), strained
3 cups granulated sugar
6 ounces liquid pectin, such as Certo (you’ll need two 3-oz. packs)
2 tablespoons fresh lemon juice
Coarse sugar (such as Hain Organic); or use granulated

Line an 8-in. square baking pan with microwave-safe plastic wrap, pressing it up sides and leaving a 1-in. overhang. Spray plastic wrap with cooking spray. Pour citrus juice and granulated sugar into a 6-qt. pot and stir to combine. Clip a candy thermometer to inside of pan. Cook over medium-high heat, stirring constantly and slowly, until mixture registers 238° (just before the soft-ball stage, when it will harden), about 20 minutes. Add pectin and cook 1 minute more, stirring constantly. Remove from heat, stir in lemon juice, and immediately pour into prepared pan. Let set until cool and firm, about 1 1/2 hours. Lift from pan using plastic wrap and cut into 1-in. squares, circles, 3/4- by 1 1/4-in. rectangles, or 3/4- by 2-in. half-moons. Dip in coarse sugar. Store in an airtight container up to 1 week, dipping again right before wrapping if necessary (particularly with the more acidic flavors like lime, lemon, and grapefruit, which tend to get a little weepy). Box it: Crystal clear boxes, from $6.2 5/25; clearbags.com