Now an article HERE tells the secret for making perfect crisp fries every time.
You can do it at home.
"McDonald's French fries are shipped to outlets frozen. "We do all of ours fresh everyday," says Myers who uses the same recipe at his restaurants and at home. Myers also uses the best Idaho russet potatoes, French sea salt, and super fresh cooking oil.So there is the secret to crispy fries. Soak them first to remove more starch.
He says the key to making a perfect, consistent, McDonald's-style fry is in the advance preparation. The cut potatoes need to be soaked for at least two hours before cooking which pulls out excess starch and ensures the crispiest product. Also, Myers recommends that, "you have plenty of paper towels, a lined sheet pan, and have your oil ready to go."
Just be extra sure you dry them out pretty well or they will spit and crackle badly when placed in hot oil and that is dangerous.