Hey Randy
I "was" a french fry addict, especially McD's fries from the 80's, (which was followed by a love of seasoned curly fries) so this is another one of my fortays. I have alot to share so bare with me.
Potato
Soaking
Blanching
Frying medium
Final frying
Salt
Potatoes
First off, I recommend Russets to achieve a McDonalds type french fry. I find red potatoes have too fine a texture and too sweet to mimic McD's fries from the 80's. They make a good Fry, just not a McD's.
The age of the potatoes plays a role in the final outcome of your fries. Older potatoes that have moisture loss will become a bit rubbery and eyes will most likely have started to develop. These are ideal for fries with a crisp exterior and a perfectly cooked middle. As a matter of fact these potatoes usually wont darken after being cut, not even a light pink, therefore eliminating the need to rinse them and will allow the starches to remain.
Soaking
I have mixed feelings about soaking the newer, firmer potatoes (russets). I usually have to, inorder to prevent darkening (I'm never allowed to make a small batch.) But when I consider what I had observed about older potatoes and moisture loss, soaking seems counter-intuitive. But when I do soak, I will add salt so that the potatoes will absorb some of the salt and enhance the flavor. I will also dry the potatoes thoroughly with a kitchen towel.
I have tried adding sugar and corn syrup to soaking water, the fries develop a deep caramel color, that I just don't recall McD's fries having. I remember a few fries being a bit darker at the ends but mainly being more of a golden color similar to the modern frys. But maybe my memory is failing me on this one. So you may want to give this method a try, I'll post the formula if you'd like it.
side note: Today's fry's are covered in something called invisi-coat, which I believe is somthing along the lines of baking powder or a baking powder-starch blend, but cannot confirm this, it's just a hunch.
My step-son finally got in, and it's really late, so I'll finish this later. Probly Monday.
This is an old thread, so Randy, if you have any updates, I'd be interested in hearing about them.
I appologize for the "to be continue thing" but it's very late and I really need to get into bed, now that I can.