Candymaking is chemistry at its absolute coolest. In the span of just 60 degrees on a candy thermometer, sugar syrup can turn from wispy strands to gelatinous balls to brittle shards, yielding sweets that range from rock candy and fudge to gummies and lollipops in the process. Here, classic candies get the gourmet treatment—no artificial dyes or unpronounceable stabilizers—just good old-fashioned sugar, water, and some knockout flavor combinations to take your candy crush to a sweet new level.
Sugar is straight-up wild, man—at least when you turn up the heat. Granulated sugar (sucrose) is composed of fructose and glucose molecules, which, at room temperature, are all stuck together in a neatly organized pattern. But expose sugar to heat, and those molecules separate, leaving the molten sugar syrup in a woozy, unstable state.
Sugar has an affinity for its natural, orderly crystalline structure; if left to cool undisturbed, the molecules will realign, stacking into chunky, distinctly visible crystals, like the Peppermint Rock Candy. Stirring the cooling sugar syrup interrupts this process; the sugar forms tiny crystals that are too small to be detected on the tongue, resulting in candy with a smooth and creamy mouth-feel, like the fudge at right. Introduce air to the equation, and the texture changes completely, yielding the crackly Pistachio- Rose Brittle; stirring in fat also leads to changes in texture (see “Totally Tubular Texture,” below).
While certain ingredients do impact the texture of candy, the most important factors in the formation of different candies are temperature and time (see “The Six Sugar Stages,” below).
It’s all about water—or the lack of it. Sugar and water are the build-ing blocks of candy; the longer and hotter they’re cooked, the more evaporation occurs. The less water, the more concentrated the sugar solution, which allows the sugar molecules to tightly pack together into a compact, hard candy, like the Red Hot Lollipops. While a candy thermometer is the most reliable tool for testing temperature (scroll down for our favorite model), veteran candymakers swear by the venerable cold-water test. Literally cooking by feel, this method involves dropping a small dollop of the hot syrup into a glass of very cold water, letting it cool slightly, then touching it to determine the texture. The resulting feel is assigned to one of six stages, the gospel of candymaking.
Thread Stage (215°F TO 230°F) Soft, loose, short strands
Soft-Ball Stage (234°F TO 240°F) Soft, pliable, sticky ball
Firm-Ball Stage (245°F TO 250°F) Firm, malleable ball
Hard-Ball Stage (252°F TO 266°F) Solid ball that will flatten if pressed
Soft-Crack Stage (270°F TO 290°F) Long strands that are firm but flexible
Hard-Crack Stage (295°F TO 310°F) Stiff strands that are firm and brittle
Making candy at home doesn’t require a separate pantry full of gear, but these special tools and items will make the process easier.
Your grandmother’s retro candy thermometer (likely hiding in the back of your kitchen drawer) will work perfectly for these recipes; if you’d like to level up, we recommend the clip-on Taylor stainless steel paddle thermometer, available at amazon.com.
If you plan on storing candy for an extended length of time, consider purchasing silica gel packs, which when popped into storage containers will absorb moisture and keep your candy structurally sound and looking beautiful. Find them at amazon.com.
Whether you like it gooey-chewy or crackly-crunchy, texture plays a huge role when it comes to enjoying your favorite candy. Chewy candies like caramels and gummies owe their smooth, satisfying texture to interlopers. Known in the candy circuit as “interfering agents,” these ingredients (such as corn syrup, fats, and acids) alter candy texture by butting in and preventing sugar crystals from reforming in an orderly fashion. Acidic ingredients, such as lemon juice and cream of tartar, damage the chemical bonds, preventing the molecules from re-attaching and causing graininess. Fats like butter and cream also interfere with crystallization, keeping caramels soft and satiny.
On the crunchy end of the spectrum, the Pistachio-Rose Brittle has a surprising ingredient to credit for its crackly texture: air.
While some candies, like saltwater taffy, are aerated manually, honeycomb toffee and brittle are aerated through the magic of chemistry. Adding alkaline baking soda to naturally acidic sugar produces thousands of tiny bubbles; these carbon dioxide pockets get trapped in the solidifying candy as it cools, creating a sponge-like, porous texture.