What actually occurred to me, was that the interior of the fries is functionally sterile, due to the high heat, and the surface crust has a very low water activity – too low to support the growth of bacteria or molds. Water activity refers not to the actual percentage of water, but the amount of “free” water. Thus, even some relatively “wet” foods, such as jelly or honey don’t support the growth of bacteria or molds, as the bulk of the water is associated with sugar molecules and therefore unavailable for microbial growth…there’s a somewhat technical explanation here: http://www.lsbu.ac.uk/water/activity.html

While I don’t have any info on hand about the water activity of McDonald’s fries, this patent: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5,997,938.PN.&OS=PN/5,997,938&RS=PN/5,997,938 from Procter and Gamble describes an oven-finished french fry product with a surface water activity below 0.45. As noted in the link to the explanation of water activity, absolutely nothing will grow below 0.6. Thus, as long as the surface crust isn’t broken or appreciably dampened, not much would happen to them.

It’s also not impossible that they put something on the surface to prevent discoloration of the cut surfaces by enzymatic action (like sodium sulfite). This could also deter microbial growth, as would the salt added after frying.

So it’s probably not as nefarious as it looks. Manipulating water activity is a classic food preservation technique.

Don’t get me wrong: McDonald’s fries are pretty gross, IMHO: but you have the fry-o-later fat to thank for that, I think…and in that, they’re no different than most other deep-fat fried restaurant foods.

Years ago, I worked as a restaurant cook, so had to change the grease in the deep fat fryers at the end of my shift. It was awful stuff: thick, greasy-smelling and coffee-colored. Fresh grease started out quite pale and foods had to be cooked for a comparatively long time before they’d develop that nice, golden brown color characteristic of deep fried foods. But as successive batches were cooked, various compounds that leached out of the food would polymerize in the continuously heated oil, and stick to subsequent batches of food, so the food cooked in it would get toasty much faster.

The darker the oil, the darker the food. Eventually it would get too dark (the food would get brown before completely cooked through – lol), and would have to be changed. A good analogy would be the La Brea Tar Pits: the stuff was dark from heat-catalyzed organic chemical reactions. Mmmmmm…

These days, I avoid anything that comes out of a restaurant deep fryer.

Given your background – explain this Franken food – what in the H E double hockey stick is in the fries sold at the local Mc Joints et.al that allows them to age gracefully for well over a year and not go moldy or disintegrate??

Every year our crew trucks (construction) come in for a clean out, and among the left over, moldy, stinky sandwiches, and fruit there is always some franken fries in pristine shape, looking like they just came out of the deep fryer!! If bacteria won’t touch this “food” what are people doing eating it? Kinda scary eh!