Prepare the corn. Cut the kernels from the fresh corn cobs, removing any remaining pieces of silk.
Start frying the corn. Heat the vegetable oil in a large 10–12-inch skillet over medium-high heat. Add the corn kernels and cook for 5 minutes, stirring frequently as the kernels release moisture.
Add the bacon grease. Stir in the bacon grease and continue cooking over medium-high heat. Stir approximately every 5 minutes to help the kernels cook evenly.
Brown the kernels. As the excess moisture cooks away, the corn will begin to develop golden edges and brown spots. Continue cooking until you notice the kernels beginning to caramelize.
Lower the heat and season. Reduce the heat to medium once the corn begins turning golden brown. Season with salt and black pepper to taste.
Finish with butter. Add the salted butter and stir to coat the kernels. Continue cooking until approximately one-quarter of the kernels have developed golden-brown spots while the remaining kernels are still yellow.
Serve. Remove the skillet from the heat, allow the corn to cool slightly, and serve.