I want to know why fast food fries turn into sharp hard sticks when cold but fries I make at home get soft and floppy when cold. I’m using real potatoes, are they? I suspect some kind of formed, Styrofoam type potato product is cut up instead that-when fried- melts into an inedible projectile.
Your grease is not hot enough.
America’s Test Kitchen has the best recipe. The short form is:
Peel potatoes and cut into fries.
Rinse starch off fries.
Immerse in ice water for at least 30 minutes.
Dry.
Fry at approx. 325F until golden brown.
Remove and let fries rest for 10 minutes on paper towel.
Fry at approx. 350F for about 1 minute.
Remove to paper towel, salt and eat.
In my fryer, I set the temps to 350F and 400F. Plus, I fry longer. The second fry adds crispness; it takes about 6 minutes with my fryer.
Do you parboil your fries before frying them? If not, that’s probably the difference.