Husk the fresh corn and remove all silk strands. Using a sharp knife, carefully cut the kernels off the cobs into a large bowl.

Working in batches, add the corn kernels to a blender or food processor. Pulse until you achieve a coarse, chunky texture - not completely smooth. The mixture should resemble a thick, grainy batter with some corn pieces still visible.

Transfer the ground corn to a large mixing bowl. Add the salt, melted butter, and sour cream. Mix thoroughly with a wooden spoon until well combined. The batter should be thick but spreadable. If too thick, add 1-2 tablespoons of milk; if too thin, let it rest for 5 minutes to absorb moisture.

Heat a large cast iron skillet or griddle over medium heat. Lightly brush with vegetable oil.

Using a 1/4 cup measure, pour batter onto the hot griddle. Use the back of a spoon to gently spread into a 4-5 inch circle, about 1/2 inch thick. Do not press too hard - güirilas should remain fluffy.

Cook for 4-5 minutes on the first side until the bottom is golden brown with some charred spots and the edges begin to look set.

Carefully flip using a wide spatula. Cook for another 3-4 minutes on the second side until golden and cooked through.

Transfer cooked güirilas to a plate and cover with a clean kitchen towel to keep warm while cooking the remaining batches.

Repeat with remaining batter, adding a light coating of oil to the pan between batches as needed.

Serve warm immediately, or keep covered until ready to serve.