One of the shows I enjoy watching on TV when I'm not feeling well is How Its Made which is just a series of those factory-construction videos back to back, showing how pretty much anything is manufactured, from ambulances to spoons. Its just fascinating to watch all the machines and how things are put together and it really makes me appreciate the thought and work that went into inventing those devices and creating different products.
Oh, and none of the shows are from China, none of the plants or manufacturing facilities. Along those lines is this video of how McDonald's fries are made, its pretty interesting stuff to me, and it does help dispel a few myths people might have in their minds:
The fry salting device is devised so it only measures out a single portion of salt each time, so they have to turn it back over and dump more in if they want to add more salt. I've always thought McDonalds' fries are a bit undersalted if anything myself.
The process of making really great fries is pretty complex, and I haven't ever done it at home because its so long and troublesome. If you just dump potatoes into a vat and fry them up, they're pretty good, but you don't get those ideal french fries if you do it that way; they cook unevenly and the outside tends to get too dark by the time the inside is properly fried.
Making good fries requires almost exactly the same size of fries, both in length and thickness. McDonald's has a 9/32nd (just over a quarter inch) fry, which is chosen more or less arbitrarily but it allows them consistency in cooking time and packaging. I like what they call "steak fries" better, they're a half inch or more. If you don't have them all about the same size, they cook at different rates, so some get overdone and some underdone. Its just at home its a pain to get them all exactly right, and I'm not going to throw out any fries because they are too small, its a waste.
The first step is to get the uncooked potatos as dry as possible, or they'll cause problems in your frier. Water superheats and when water sublimates (turns to gas, or steam in this case) it increases in size by 1600 fold, an immense amount. When you have a lot of water instantly turned to steam by hot oil (remember water sublimates - boils and turns into steam - at 212 degrees Fahrenheit (100 Celsius) and your oil will be well over that), it can easily cause your oil to almost immediately boil over and onto the flame, the stove, the floor, even you. That's not fun, and even if you don't burn the house down, its a real pain to clean up. Hint: use kitty litter to soak it up first.
First, heat up your oil in a deep frier or deep sauce pan to medium heat, you don't want it super hot, but 300-325. For each quart of oil in the frier, you go with about a single large potato's worth of fries. Any more than that and you'll lower the temperature of the oil too much. Any less and you're wasting time by underloading the frier. Let the potatoes fry for 4-6 minutes, just enough to start to change color. Pull them out, drain them, and pat them down with a paper towel to get rid of excess oil. Put them aside for at least 10 minutes, to cool, but you can go as long as 2 hours. This is why its a bit fussy and time consuming - blanching, or pre-cooking the potatoes not only makes them cook more consistently and completely but it changes the chemistry inside the potato so the starches start to turn into sugar and it gives the fries a different taste than just potato.
Then, just when you're about to serve them, get that oil going again, this time on high, for a temperature of 350 degrees. Dump your fries in the same proportion as above, and fry them for a minute or so, until they are puffy and golden brown in color. Drain them and salt them, and serve!
If you insist on battering your fries, which can be quite good, all you do is between blanching and final frying, add some batter to them. The best way to do so is the chicken fry method in which you dip the fries into milk (evaporated milk especially works well as it is a bit thicker, although good unpasteurized whole milk works too) then into the dry batter mix. You can make it real simple with flour, salt, and pepper or add more into it like onion powder, paprika, cayenne pepper, or whatever. The milky potatoes are coated well with the flour mix, and then you fry them up as usual.
Be aware, however, that you're going to make your oil very, very messy by doing this, and it won't really be reusable afterward. Also, a trick for doing this kind of battering is to use the "wet hand, dry hand" method: use one hand to handle everything that's wet, and the other to handle everything that's dry. Left hand dips the fries and puts them into the flour, right hand picks up the dry and coated fry and puts them into the ready dish for frying.
That's how to make really great french fries. Yes, its a lot of work. You don't need the citric acid and dextrose coating McDonald's uses, because you aren't storing or freezing your stuff, you're just readying it to cook. If you have to prep and keep potatoes a while, store them in fresh cold water with some lemon juice in it (or powdered vitamin C, about a teaspoon per gallon should do) for a day or so and you can even skip the blanching process listed above.
Incidentally, McDonald's Canada has done a lot of these how we do things videos and they're all pretty cool, a time killer on Youtube.
*This is part of the Real Men Cook series.