Homemade Peanut Brittle that is exactly like Grandma made! It's perfectly crisp and crunchy, perfectly caramelized, deliciously buttery and brimming with roasted peanuts dotted throughout. Read through the recipe and notes before beginning.
Measure out all ingredients and have close by ready to add.
Butter bottom and sides of a rimmed 18 by 13-inch baking sheet. Also butter the bottom of large spoon and set close by (you'll use this later for spreading brittle).
Preheat oven to 200 degrees. Once preheated place baking sheet in oven, turn oven off and let baking sheet stay warm in oven. Remove baking sheet just barely before you are ready to use it to spread prepared brittle mixture over.
In a 3-quart heavy bottom saucepan whisk together sugar, corn syrup, and water.
Set over medium heat and bring to a boil, stirring occasionally.
Once it reaches a boil carefully add butter and stir.
Let boil, stirring occasionally, until it reaches 310 degrees on a candy thermometer (don't forget to get your baking sheet out of oven and ready near the end). The mixture should just have turned a light golden brown color.
Immediately remove from heat once it reaches temperature (or just turn off heat if using a gas stove) and right away add baking soda, salt, and peanuts and give it about 5 quick stirs (it will foam and bubble up).
Immediately pour onto warm baking sheet and spread mixture out using greased spoon, spread as evenly as possible before it starts to harden.
Let cool completely at room temperature, about 30 minutes. Then break into pieces.
*Salted peanuts will work fine too. Just omit the salt from the recipe. Also use peanuts that don't have added ingredients. Peanuts/salt should be the only ingredient. No added spices (some have onion powder, paprika, etc) or oils.
Be sure to have everything measured out and ready to add before you begin cooking, timing is critical in this recipe and if you were to wait even 5 seconds to add something it can be too late.
Stir occasionally (a little more so at the end than the beginning) for even cooking and to prevent bottom or sides from scorching.
If you live in a cold environment you may find it helpful to heat the peanuts in the microwave for 35 seconds. Do this about the point the brittle reaches 275 degrees (so they are ready to add). If you add them cold or cool the sugar mixture will clump right up.
If you're brittle didn't spread very well, a helpful fix is to let it cool briefly just until it's cool enough to handle with clean (thickish) rubber gloves. Then pull and stretch the brittle while it's still pliable.
Once cool and broken store in an airtight container at room temperature about 1 month or freeze up to 3 months.