1-Getting started with caramel corn: First, preheat your oven to 200 degrees Fahrenheit and line one or two 12×17-inch baking sheets with silicone mats or parchment paper. This setup helps the popcorn bake evenly and prevents sticking.

2-Prepare the popcorn and caramel mixture: Next, place your 10 to 11 cups of air-popped popcorn in a large bowl or directly on the prepared sheets. In a medium saucepan over medium heat, combine the light brown sugar, corn syrup, unsalted butter, salt, and cream of tartar. Stir constantly until the butter melts and the mixture begins to simmer, then let it boil for 4 minutes without stirring.

3-Cook to caramel consistency: If you’re using a candy thermometer, aim for 234 to 235 degrees Fahrenheit to get that ideal caramel consistency. Once it’s ready, remove the pan from the heat and stir in the baking soda, which will make the caramel bubble and foam for a lighter texture. Pour this warm caramel over the popcorn and gently mix to coat every kernel evenly.

4-Bake and cool: Spread the coated popcorn out on your baking sheets and bake for 1 hour, remembering to stir every 20 minutes for even crispiness. After baking, let it cool on the pans for at least 30 minutes so the caramel hardens just right. Once cooled, break it into clusters and enjoy; this step ensures the popcorn stays fresh for up to 2 weeks in an airtight container.