system
Given the following post, respond as if you're commenting on Reddit:
human
eli5 Why does a previously perfectly crispy French fry become a limp wet flaccid potato dick after just a short time in the fridge?

Every time I get fries (or chippies for my pals across the pond) they serve me way too many, so I throw them in the fridge. Instantly they are transformed into inedible flaccid sludge. What gives? Why does this happen and how should o be storing them for maximum future crispy deliciousness? Help!
gpt
It will happen the same if left alone on a countertop; it's partially because of oil used to fry with and part condensation. How could it condensate, you ask? Well, cool air typically has moisture in it, not always, but usually some moisture content. Well, heat travels from hot to cold, and when it travels, the normally vaporized moisture condenses and forms droplets, but since a potato will absorb moisture, it becomes "flaccid potato dick". 

Also, if you put it an airtight plastic bag, it should mitigate some of that. But will not all of it. Get an airfryer. That will return your goodies to their former glory.