Homemade Peanut Brittle Recipe

When you're craving something sweet and salty, there's nothing better than a little peanut brittle. Like its name suggests, peanut brittle is a hard, thin sheet of glossy, smooth, buttery caramelized sugar candy that's studded with roasted peanuts and cracks easily into bite-sized, melt-in-your-mouth pieces. If only peanut brittle were as easy to make at home as, say, chocolate chip cookies. Well, the good news is, it totally is! 

This recipe for homemade peanut brittle, which is brought to you by private practice registered dietician and recipe developer Kristen Carli, takes about half the time of your typical chocolate chip cookie recipe. It also comes together in a single batch with just one saucepan and one baking sheet. As a matter of fact, this recipe for homemade peanut brittle is downright easy to make, according to registered dietitian and recipe developer Kristen Carli, provided you equip yourself with one simple tool: a candy thermometer. A candy thermometer is just like any other cooking thermometer, except its temperature typically reads up to 400 F, and it comes with a probe that can withstand being in boiling sugar syrup (via The Grubwire).

"It's very important to have a thermometer and to use it to measure the temperature at each stage [of this recipe for homemade peanut brittle]," according to Carli. If you don't have a candy thermometer, let this delicious recipe for homemade peanut brittle be your inspiration to pick one up. In all likelihood, you'll be able to do so at your local grocery store, which you'll need to visit if you need to pick up some light corn syrup or unsalted roasted peanuts. Those are probably the only ingredients in this recipe that you might not have at the ready. The other ingredients — sugar, salt, vanilla extract, butter, baking soda, and water — all tend to be the sort of staples you usually have on hand.

To get started making your homemade peanut brittle, the first thing you'll want to do is forget everything you've heard about why you're not supposed to grease your baking sheets. When it comes to cookies, you should not grease your pans. Doing so can potentially make the cookie batter spread out too thin, thereby burning the cookies — and no one likes burnt cookies! When it comes to candy making, however, go ahead and grease up an extra large baking sheet with butter. When your homemade peanut brittle comes right off the baking sheet, you'll be so glad you did.

Peanut brittle gets its name from the brittle consistency of the candy that binds the peanuts together. That consistency requires a sugar syrup that's been cooked to what's known as the "hard-crack" stage, according to Science of Cooking. The "hard-crack" stage refers to what happens when you add a bit of sugar syrup to some cold water. This will result in "threads" that will crack if you try to bend them. From a scientific standpoint, the hard-crack stage means that the syrup is just about water-free (via Science of Cooking).

To make your sugar syrup for your homemade peanut brittle, simply stir the water, sugar, and corn syrup together in a medium-sized saucepan over medium heat, and continue stirring until you see the syrup bubbling. Once boiling, stop stirring, but keep an eye on the thermometer. You're waiting for it to hit 240 F.

Without peanuts, peanut brittle is just, well, brittle. But knowing when, and at what temperature, to add the peanuts is critical to the success of your homemade peanut brittle. Accordingly, once the sugar syrup's temperature reads 240 F, it's time to add the peanuts. Stir them in to combine, and continue stirring constantly over medium heat until the thermometer gets to 300 F.  

When the thermometer reads 300 F, immediately remove the saucepan from the heat source, then stir in the butter, baking soda, salt, and vanilla extract. If you're wondering what baking soda is doing in this recipe for homemade peanut brittle, Carli explains that the "baking soda helps to create the candy texture that snaps when you break it into pieces."

Immediately after stirring in those last few ingredients, pour the mixture onto your prepared baking sheet, spreading it into a thin, flat layer — one that is thin enough so that the peanuts really stand out from the syrup. Allow your homemade peanut brittle to cool off to room temperature, which should take about 15 minutes. You can test whether it's ready by hitting it lightly with a large wooden spoon. If it cracks, go ahead and crack the whole thing into bite-sized pieces, which are ready to eat immediately. Store any leftovers at room temperature in a plastic bag.