I have heard that, to get crispy french fries, I need to get rid of the excess starch on the surface of potatoes after cutting them. But that can't be the reason, really, because starch is actually what FORMS the crust... so my reasoning is the following: we soak them because enzymes released by cutting will quickly convert the starch into glucose, and THAT will caramelise and burn our french fries. Is that the reason why we use cold water, to keep the enzyme inactive?

If so, soaking in cold water seems unnecessary to me. Thoroughly rinsing until the water runs clean should be enough. Am I correct?

  • 6
    Soaking is probably less important than blanching, and fry perfection is quite complex. I know no one who has investigated this more than Dave Arnold. No need to reproduce all the gory detail, which can be had here: cookingissues.com/index.html%3Fp=4043.html
    – moscafj
    Commented Jan 5, 2016 at 13:41
  • 1
    Thank you moscafj. That link will keep me busy for a while. Biiiig thanks, that is one leven up! Willem, whatever works for you of course, no problem. I am digging into the chemistry and technique as deep as I can...I have made FF for decades, and have seen many many ideas. I am trying to find out WHY. We cooks tend to follow authority, in stead of experiment. Call it evidence based cooking (much like medicine, that is an art and is trying to incorporate experiment. Dont steal the term, I am trying to get rich with it..;-)
    – Marc Luxen
    Commented Jan 5, 2016 at 20:23
  • See also: cooking.stackexchange.com/questions/78898/…
    – Jolenealaska
    Commented Mar 5, 2017 at 22:52
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    The cooking issues link has a lot of good information, but one thing they didn't test for is tossing the fries to rough up the outer surface before the final fry. It's possible that they didn't do it as it's more typical for Dutch & Belgian fries, which tend to be less slender (shorter and thicker) than American fries, so they can take rougher treatment.
    – Joe
    Commented Sep 19, 2018 at 14:50

4 Answers 4


According to https://foodcrumbles.com/should-you-rinse-or-soak-potatoes-before-frying-an-experiment/

when it comes to crispiness it makes little difference whether you soak for a long period of time or not (it only affects the color). So you are basically correct that thoroughly rinsing until the water runs clean should be enough.


The reason why you want to get rid of the excess starch on the surface is, while cooking they will brown faster and will yield very dark brown fries, instead of golden-brown "which we all like ;)". It has nothing (or little) to do with enzymes aiding caramelization/maillard reaction. The browning happens at high temperatures, such as the temperature of the frying oil. As you have more starches on the surface, they will get darker, or even burnt.

As a side note, I’ve found out that instead of soaking, just cooking the fries in water for a short while helps greatly in getting rid of the surface starches, even more than soaking or running them through water.

  • 1
    I never soak my fries and actually prefer the dark color (although I always thought this was due to a different variety of potatoes), it's one part of what makes the so much better than fries you can buy everywhere.
    – JohnEye
    Commented Oct 15, 2018 at 15:31

I just know that when I soak them they don’t stick together when fried. Also it doesn’t just reduce starch it can reduce Acrylamide in the potatoes. That’s why I soak them at least. I never soak longer than 1 hour if I’m prepping dinner and sometimes I just rinse if I’m in a rush.


Soaking French fries in cold water is done for two reasons. This takes out the excess starch from the outside of the potato. Let them soak for a minimum of four hours in your refrigerator. They can stay in the water for up to some 24 hours or so with no harm coming to the potatoes. Be very careful in drying the fries before putting them into the oil? Water and oil do not mix. The second reason for soaking is that it has the advantage of keeping the fries from getting too dark during the cooking process. https://www.youtube.com/watch?v=hZJ739iMYXI

  • Please read the question....WHY soak a long time, and I dont think the starch is the problem.
    – Marc Luxen
    Commented Feb 8, 2016 at 12:23

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