Classic Old-Fashioned Peanut Brittle Recipe

Note from my kitchen: I tested many variations over the years. This version delivers the ideal buttery crunch with no tricky techniques — just a candy thermometer and a heavy pan. A generous batch comes together in under an hour. If you want the candy-shop classic, this is the recipe.

The two most important things are preparation and temperature control: measure everything before you begin and trust your candy thermometer. Have the butter, baking soda, and vanilla at arm’s reach, because once the syrup reaches hard-crack stage you’ll need to move quickly. Lining the pan with parchment makes cleanup easy, and spreading the brittle thin yields that perfect, light snap.

What You’ll Need

For the brittle

• 2 cups granulated sugar
• 1 cup light corn syrup (light corn syrup gives a pale, honey-colored brittle; avoid dark corn syrup for this recipe)
• ½ cup water
• ½ teaspoon salt
• 2½ cups raw peanuts (use raw peanuts — pre-roasted nuts will overcook at these temperatures; you can substitute chopped raw almonds for an almond brittle)

To finish

• 2 tablespoons unsalted butter
• 1 teaspoon vanilla extract
• 2 teaspoons baking soda (this creates the light, airy texture — don’t skip it)

1. Prep everything first

Before turning on the stove, line an 11×15-inch (or similar) baking sheet with parchment and place it on a heat-safe surface. Measure the butter, vanilla, and baking soda into small bowls so they’re ready to add immediately. Clip your candy thermometer to the side of a heavy-bottomed pan. Once the syrup reaches the final temperature, you’ll have only seconds to work, so having everything staged is essential.

2. Cook the sugar mixture

Combine the sugar, light corn syrup, water, and salt in the pan. Stir just until the sugar is moistened, then stop stirring — excessive stirring can cause crystallization. Cook over medium heat until the mixture reaches 250°F (soft-ball stage), which usually takes 20–25 minutes. Keep the heat moderate for an even, controlled cook; rushing with higher heat risks burning.

Tip: If you don’t have a thermometer, the water test will tell you when the syrup is at soft-ball stage: drop a small amount into cold water — it should form a soft ball that flattens when pressed.

3. Add the peanuts

When the syrup reaches 250°F, stir in the raw peanuts. The addition will cool and thicken the syrup slightly — that’s normal. Continue cooking and gently stirring so the peanuts toast evenly without scorching. Watch for the thermometer to climb to 300°F (hard-crack stage), about 8–10 more minutes.

Tip: The color will deepen to a light golden caramel. If the mixture becomes too dark or smells burnt, remove it from the heat immediately — burnt brittle turns bitter fast.

4. Add butter, vanilla, and baking soda

When the mixture reaches the hard-crack stage, remove the pan from the heat and quickly stir in the butter, vanilla, and baking soda. The mixture will foam as the baking soda creates tiny air pockets — this gives the brittle its lighter texture and snap.

5. Pour

Immediately pour the foamy mixture onto the prepared baking sheet. Use a heatproof spatula or the back of a spoon to spread it into a thin, even layer. Working quickly helps ensure an even thickness and consistent crunch.

Safety reminder: The pan and syrup are extremely hot. Do not touch or taste until fully cooled.

6. Cool and break

Allow the brittle to cool completely at room temperature for about an hour. Avoid refrigerating it, which can introduce moisture and make the candy sticky. Once cool, lift the parchment and break the brittle into pieces using your hands or the back of a spoon. Store in an airtight container at room temperature for 2–3 weeks.

Tip: In humid kitchens, include a small silica gel packet or a sheet of wax paper between layers to help keep the brittle crisp.

Storage instructions

Making treat tins

Peanut brittle makes a classic addition to holiday tins alongside cookies and candies. Because the brittle is fairly brown in color, pair it with brighter or differently colored treats for visual contrast. Popular companions include thumbprint cookies, fudge, and light-colored candies or cookies. Pack items snugly but separately so flavors don’t transfer.

Troubleshooting