Using the shredding disk of a food processor, shred the potatoes and immediately put into a big bowl of cold water in between shredding batches, to prevent browning.
Rinse the shredded potatoes in a colander, then put back into a big bowl of cold water. Soak for 10 minutes, then drain and rinse again.
Squeeze as much water from the potatoes as you can with your hands, then transfer to a kitchen towel and wring out the potatoes even more, soaking up any moisture that you can.
Unless you have a really large skillet, like 14", I recommend using two nonstick skillets to cook (I use a 10" and a 12"). Heat each one over medium heat, and melt 2 tbsp of butter in each pan.
Split the shredded potatoes between the two pans, and season each batch with ¼ tsp salt, and ⅛ tsp black pepper.
Let the potatoes sit in the pan for 4-5 minutes, without stirring, until the bottom has browned, then start tossing the potatoes around to start cooking the other side.
Add another 2 tbsp of butter to each pan, and cook for an additional 15 minutes, stirring/flipping every 5 minutes or so, to continue cooking and browning the hash browns.
Do a final taste test for seasoning, and add more salt and pepper as needed. Serve promptly, while warm. Enjoy!
