#1 Secret Recipe For McDonald's French Fries Brandi Malloy shows us how to make McDonald's french fries by first cutting a potato into 1\/8 inch slabs. #2 Matchsticks Then slice those slabs into matchstick pieces. #3 Soak The Potato Sticks Soak the potato sticks in water mixed with some corn syrup and place in refrigerator for 30 minutes #4 Peanut OIl Brandi uses peanut oil because it has a high smoke point and neutral flavor. #5 First Fry Brandi fries the potatoes twice for extra crispiness. The first fry is at 375 degrees for just 90 seconds to burn off the starch. #6 After First Fry Refrigerate the fries for 10 to 15 minutes. #7 Finished Product Your finished product should look like this and taste almost identical to McDonald's Fries.