Heat the oven to 250 degrees F. Butter a large roasting pan. Combine the popped corn in the prepared pan. Place in the oven while preparing the glaze.
Place red hots into a 2 cup measure and fill to the top with sugar. Boil red hots, sugar, butter, corn syrup and salt for 5 minutes. Remove from heat and add soda and oil. Stir well and pour over popped corn, tossing quickly to distribute evenly. Bake for 1 hour stirring every 15 minutes.
Remove from oven. Using a metal spatula, free the popcorn from the bottom of the pan. Let cool completely in the pan.
Break into clumps.
Store in an airtight container at room temperature for up to 1 week.