The Science Behind the French Fry

Ah, French Fries. So delicious, they are the poster child for taking something wholesome and nutritious and making it fattening and artery clogging and they are one of the reasons potatoes get such a bad name. But let’s face it, most of us like a good fry once in a while. I have worked for a potato company for over 15 years and I have seen potatoes fried in a myriad of ways, but did you know there is a wrong and a right way? And that there is a science behind which potatoes are the best for frying?


The key to great fries is in the solids and sugars of the potato. When companies like mine test their potatoes for frying, one of the first things that they look at is the Specific Gravity. This measures the potato for solids. That may sound weird, but potatoes are made up mostly of water. Water and oil don’t mix that well, so the higher the solid or Specific Gravity of a potato, the better chance those French Fries will be golden and delicious. Burbank Russet potatoes have long been hailed as the best frying potatoes and they are still top of the list because their solids are higher than many other potatoes. But a potato that many food service and restaurants are using (which is not available to the general public) is the Pure Gold potato. Unfortunately this potato is ugly with netting all over it and an uneven skin so it is not viable in the consumer market. This potato is a yellow skinned, yellow fleshed potato that yields the best French Fry that I have ever eaten. The fry is always the perfect golden and the taste is unbeatable.

When we fry potatoes we also test for glucose content in the potatoes. It is another important aspect in getting the perfect fry. You don’t want the potato to have too many sugars as it will change the way the potato fries. Remember if you store your potatoes in a refrigerator, the sugar content in that potato goes up and yields fries that aren’t as golden as those stored in a cabinet or pantry.

No matter what type of potato you decide to use for your French Fries, we have a fantastic “how-to” fry video online featuring our Chef Bryan showing how he gets the perfect French Fries. His technique works and produces a golden, delicious French Fry every time. But that isn’t the only way you can fry. Here in our offices we do a fair amount of fry tests so that we can weekly keep our food service customers informed that the potatoes we are shipping that week are frying consistently.


We have a standard way that all of our fry tests are done, that I will share with you here. The first thing we do is we cut the potato into strips. We have a commercial cutter here in our test kitchen that is worth its weight in gold when it comes to cutting fries. It keeps all our fries consistent in size. We then rinse those and spin them in a salad spinner. We spin them to take off the excess water. Once we have the water spun off the fries, we put them into a 300˚ F fryer for 3 ½ minutes. Then we raise them out of the oil and let them sit and “rest” for a couple minutes before returning them to a 350˚F fryer for an additional two minutes. Voila, delicious potatoes.

Written by Barbara Keckler, Marketing Manager at Potandon Produce L.L.C.