Makes 5 Cups

1. Preheat the oven to 250°F.

2. Spread the popcorn in a large, shallow baking pan and put it in the oven to keep warm and crispy.

3. Combine the butter, corn syrup, brown sugar, and salt in a large saucepan. Cook over medium heat, stirring until the sugar is dissolved, Bring to a boil and continue to cook until the syrup reaches the firm-ball stage, 245°F on a candy thermometer. Continue cooking for 5 minutes more.

4. Remove the syrup from the heat and stir in the baking soda. The syrup will foam.

5. Remove the popcorn from the oven and drizzle the syrup over it. Mix well.

6. Return the popcorn to the oven for another 45 to 50 minutes, stirring every 15 minutes. Cool and serve or store in an airtight container.