Heat coconut oil in a large pot over high heat. Add 6 kernels to pan as testers; cover. When at least 3 of the kernels pop, add remaining kernels. Shake pan occasionally as corn pops. Keep over high heat until popping slows to a few pops per second, about 5 minutes. Empty popped corn into a large brown paper bag. Add 2 teaspoons salt. Shake bag to distribute salt and drain excess oil; discard unpopped kernels. Measure 13 cups of fully popped kernels; spread on large roasting pan; set aside.
Combine brown sugar, butter, corn syrup and baking soda in medium heavy saucepan; heat to boiling over medium-high heat. Cook, without stirring, until mixture reaches 235° F on a candy thermometer, about 8 minutes. Remove from heat.
Heat oven to 250° F.
Carefully pour caramel mixture over popcorn. Stir mixture with heat-resistant spatula or buttered wooden spoon to evenly coat popcorn, working quickly to coat kernels.
Bake popcorn 1 hour, stirring every 10 minutes to continue coating uniformly. Remove pan from oven; cool on wire rack. Break apart any clumps of corn with your hands.
Tips for success:
- Use white kernels for tender popcorn.
- Use coconut oil if you can find it. Though its saturated fat content is high, it makes a big flavor difference. Like shortening, it is solid at room temperature. If you can't find coconut oil, you can use peanut oil as a substitute.
- During baking, stir gently to avoid breaking kernels, but stir thoroughly to cover as many kernels as possible.
Makes: 4