Old-Fashioned Peanut Brittle

✔ Updated November 10 · new old-fashioned candy recipe with step photos, exact sugar stages and a troubleshooting table

Old-fashioned peanut brittle is sugar and corn syrup cooked to a deep amber hard crack, loaded with peanuts and lifted light with a spoon of baking soda. This is the stovetop version I make every December, with exact temperatures so yours snaps, not bends.

How Do You Make Peanut Brittle? (Quick Answer)

Why You'll Love This Peanut Brittle

• Light and shattering, never jaw-breaking thanks to the baking soda foam, which fills the candy with tiny bubbles.
• Exact temperatures in °F and °C plus the cold-water test, so you're never guessing when to pull it.
• Pantry ingredients sugar, corn syrup, peanuts, butter and baking soda. That's it.
• Deep toasty peanut flavor because raw peanuts roast right in the hot syrup.
• Keeps for 2 weeks so it's my favorite thing to box up for neighbors and teachers at the holidays.

What Makes Peanut Brittle Work

Brittle is sugar science you can taste. As the syrup boils, water cooks off and the temperature climbs through the candy stages: soft ball at 235°F, firm ball at 245°F, then hard crack at 300 to 310°F, where almost no water is left and the cooled candy shatters.

The corn syrup is there to stop the sugar from grabbing back into crystals, so the candy stays glassy instead of grainy. The baking soda goes in at the very end: it fizzes against the hot syrup and fills the candy with tiny bubbles. That foam is the difference between brittle you bite and brittle that bites back.

Ingredient Notes

Exact amounts are in the recipe card below.

• Granulated sugar: plain white sugar. Brown sugar makes a softer, darker candy that burns earlier, so I don't use it here.
• Light corn syrup: the insurance against grainy candy. Golden syrup works in its place; dark corn syrup tastes stronger and hides the peanut flavor.
• Raw Spanish peanuts: the little red-skinned ones. They roast in the syrup and the skins add a toasty, old-fashioned look. Skinless raw peanuts work the same way.
• Unsalted butter: a couple of tablespoons for flavor and a tender snap. Salted butter is fine; drop the added salt.
• Baking soda: measure it before you start and keep it within reach. Fresh soda foams best, so use a box opened within the last 6 months.
• Vanilla: it hisses when it hits the hot syrup, so stand back a little and add it with the butter.

Step-by-Step Photos

Here's how it comes together. Exact amounts, times and temperatures are in the recipe card below.

Tips for Success

• Check your thermometer first. Clip it into a pan of boiling water: it should read 212°F (100°C) at sea level, and if it reads 208°F, cook your brittle 4 degrees lower too. I check mine every December before the first batch, and it has saved me from more than one chewy sheet.
• Go all the way to 300°F. Chewy brittle means the syrup came off early: my first batch, years ago, came off at 280°F because the color looked right, and it bent like taffy. Trust the number, not the color, and use the ice-water snap test as your backup.
• Adjust for altitude. Water boils cooler up high, so sugar stages do too. Knock about 1°F off your target for every 500 feet above sea level, so at 5,000 feet, pull the brittle at 290°F.
• Pick a dry day. Sugar pulls moisture out of the air, so brittle made on a rainy, humid afternoon turns tacky within hours no matter how well you cook it. I save candy making for cold, crisp days.
• Raw peanuts go in early; roasted go in late. Raw Spanish peanuts roast in the syrup from 240°F, which is where the toasty flavor comes from. If you only have dry-roasted peanuts, stir them in at 290°F so they don't burn, and skip the added salt if they're salted.
• Don't overmix the soda. A few quick stirs and pour. Every extra second of stirring knocks out bubbles, and bubbles are what make the brittle light enough to shatter instead of chip a tooth.
• Hot sugar is a burn hazard. It's over 300°F and it sticks. No little helpers at the stove for this one, long sleeves off the pan, and keep that bowl of ice water close so any splash can go straight in.
• Use a heavy pan and the right tools. A thin pan scorches the syrup at the bottom before the top reaches temperature. I use a 3-quart heavy saucepan, a wooden spoon and the clip-on thermometer I use for candy and frying, which reads fast and clips tight to the side.

Troubleshooting Peanut Brittle

Nearly every brittle problem comes back to temperature, humidity or stirring. Here's how I diagnose a batch that went sideways.

Problem	Likely cause	Fix next time
Chewy or bendy	Pulled before 300°F, or thermometer reads high	Calibrate in boiling water; cook to 300 to 305°F; confirm with the ice-water snap test
Grainy, cloudy candy	Sugar crystals from stirring the boiling syrup or crystals on the pan sides	Stir only until dissolved, then leave it; brush the sides with a wet pastry brush
Dense and tooth-breaking	Baking soda stirred too long, stale soda, or spread too thick	Stir soda in for 5 to 10 seconds only; use fresh soda; spread to about 1/4 inch
Dark, bitter taste	Syrup went past 310°F, or roasted peanuts added too early	Pull at 300 to 305°F; add roasted peanuts at 290°F
Sticky the next day	Humid kitchen or stored in the fridge	Make it on a dry day, cool fully, store airtight at room temperature
Peanuts sank, candy is thin on top	Not stirred after the peanuts went in	Stir often from 240°F onward so the nuts stay suspended

Variations

Once the method clicks, the base recipe takes all kinds of nuts and finishes. These are the ones that get made in our kitchen.

• Salted peanut brittle: a sprinkle of flaky sea salt over the hot candy. Sweet, salty and the first tin to empty.
• Cashew, pecan or almond brittle: swap in the same amount of raw nuts. Roasted nuts go in at 290°F.
• Chocolate-dipped brittle: dip cooled shards halfway into melted dark chocolate and set them on parchment.
• Spiced brittle: stir 1/2 teaspoon of cinnamon and a pinch of cayenne in with the baking soda for a warm, gently hot finish.
• Mixed nut and seed brittle: 1 1/2 cups of nuts plus 1/2 cup of pumpkin seeds or sesame seeds, added at 290°F.

Storage and Gifting

Let the brittle cool completely, then break it up and pack it into an airtight tin or jar with parchment between the layers. It stays crisp for about 2 weeks at room temperature in a cool, dry spot.

Keep it out of the refrigerator, where the damp air turns it sticky. For gifts, I fill cellophane bags or small jars the same day I make the candy, so it stays as snappy as possible. It freezes for up to 3 months in a sealed container; thaw it sealed so condensation doesn't settle on the candy.

More Candy and Easy Dessert Recipes

For a peanut treat with no thermometer, my microwave peanut butter fudge takes 10 minutes, and my peanut butter cornflake cookies are a no-bake favorite with the same sweet, salty crunch. Brittle is one of the first things on my Christmas recipes list every year, and there are plenty more quick treats in our easy desserts collection.

Frequently Asked Questions

Why is my peanut brittle chewy instead of crunchy?

It came off the heat too early. Brittle needs to reach the hard-crack stage, 300 to 310°F (149 to 154°C), so almost all the water cooks out of the syrup. Check your thermometer in boiling water, and confirm with the cold-water test: a drop should form hard threads that snap cleanly.

Why do you put baking soda in peanut brittle?

Baking soda reacts with the hot, slightly acidic syrup and releases carbon dioxide, which foams the candy full of tiny bubbles. Those bubbles make the brittle light, porous and easy to bite. Without it you get a dense, glassy candy that is hard on your teeth.

Can I make peanut brittle without corn syrup?

Yes, but it takes care, because corn syrup is what stops the sugar from crystallizing. Swap it for an equal amount of golden syrup or honey, add 1/4 teaspoon of cream of tartar to the sugar, and don't stir once it boils. Honey versions brown faster, so watch the thermometer closely from 280°F.

Can I use roasted peanuts instead of raw?

You can, but the timing changes: raw peanuts go in at 240°F and roast in the syrup. Dry-roasted peanuts are already cooked, so add them at about 290°F, just before the hard-crack stage, or they turn dark and bitter. If they are salted, leave out the 1/4 teaspoon of salt.

How long does peanut brittle last?

Stored airtight at room temperature, away from heat and sunlight, it keeps crisp for about 2 weeks, with parchment between the layers so the pieces don't stick. Skip the fridge, where the cold, damp air makes it sticky. It also freezes well for up to 3 months in a sealed container.

Why did my peanut brittle turn out sticky?

Two usual causes: either the syrup did not reach 300°F, so it still holds moisture, or humidity got to it after it cooled. Make brittle on a dry day, let it cool fully before boxing it, and store it airtight. Sticky brittle still tastes great crumbled over ice cream.

Can I make peanut brittle in the microwave?

You can, with a timed high-power method, but the stovetop version here gives the deepest toasted-peanut flavor and far more control. Microwaves vary so much in power that timed recipes often come out chewy or scorched. With a thermometer on the stove, you hit 300°F every time.