This recipe comes from a community cookbook published in Atlanta in 1985. It’s the kind of cookbook bound with plastic rings and with the names of the people who submitted the recipes below each one. I love these kinds of cookbooks — they give a peek into people’s kitchens and the recipes they love to make. This particular cookbook is where I got my candied pecan recipe, which I make during the holidays, and it’s also the source for this peanut brittle.

You do need a candy thermometer. I tried making it without one, but it was a failure — it took too long and I got impatient, and the result was bendy and stick-to-your-teeth chewy. With a candy thermometer, the process is easy.

The key to brittle is baking soda: It forms bubbles that make the brittle light enough to break apart and eat. The baking soda reacts with the melted sugar and foams up, in the same way it reacts with acids like buttermilk, vinegar, or lemon juice to make baked recipes light. Here’s a great article about brittle, if you want to learn more.

1 1/2 cups sugar
1/2 bottle (8 oz.) light corn syrup
2 Tbsp. water
2 cups unsalted peanuts
2 tsp. baking soda

Butter a 9×13-inch baking sheet.

In a very large pot, mix sugar, syrup, water, and peanuts. Have the baking soda measured and ready in a small dish next to the stove.

Cook at moderate heat, stirring constantly, until the candy thermometer reads hard crack (just above 300F, or exactly 150C degrees). Remove from heat and immediately stir in baking soda. Pour out quickly onto baking sheet and let cool. Then break into pieces and serve.

Notes:
— Use a large pot because the mixture will foam up more than you may think. I used a 4-quart pot.
— Do not try to flatten the mixture after you pour it on the baking sheet, or you’ll break up some of the bubbles that are key to making it brittle.

Recipe originally from Melba Lehman.