I have been to several of the same gourmet hamburger and fry chain locations and sometimes the French fries are really dark and unappetizing. How can that happen?

There is no way to make fresh cut fries perfectly consistent year round. If there was, it would put frozen potato processors out of business.

There are so many variables with fresh fries. When I look at an operation this is what I usually zero in on to find the problem:

1. Did they purchase a potato that will fry? Russet Burbank, some of the yellow chipping potato varieties, etc? From Idaho?
2. Raw product, does the potato have high solids (starch)?
3. Was the potato stored too cold, turning starch to sugar?
4. Were the potatoes cut, then rinsed to remove excess starch and sugars?
5. Did the operator blanch (par boil in water or fry at a lower temperature than the finish fry) first?
6. Were the blanched fries allowed to cool without being in a covered container? The steam released after cooking can fall back on the fries.
7. Were the fries dry when placed into the fryer? Use a salad spinner or drain the fries over a metal grid to remove excess oil or moisture before frying.
8. How full were the baskets? More fries means potatoes may not fry up crispy, takes longer to cook, and can end up being darker.  Less fries in the basket will cook faster, and crisper.
9. What is the temp of the fryer set at? 350 degrees F is ideal.

Finally, there is the human factor. Staff may have different opinions on what is a full or half full fry basket, or when is a fry done. We recommend operators take advantage of the free Idaho® Potato French fry wall chart that is bi-lingual, English and Spanish, and can be posted right next to the fryer area. It shows various fry colors also so an owner or chef can circle the preferred light or dark fry color to match with the fries being prepared.

There are a number of other posts by Dr. Potato on frying, potato varieties, re-conditioning, etc. Search for the terms you are looking for to find each article.