The Case of the Mummified Burger: Update

I posted earlier about an experiment occurring at the Burger Lab (at Serious Eats Blog) testing the ability of home made and McDonalds burgers to rot under a variety of conditions. This is all in order to test the hypothesis, often stated among internet folk, that there is something strange about McDonalds hamburgers that prevents them from rotting. Well, the results are in!

Not to toot my own horn too much (just enough, I hope), I was right. The McDonalds burger doesn't rot if you leave it out - but neither does a home made burger. A McDonalds quarter pounder, however, as well as an equivalent home made burger, rot a little more and also lose moisture at a slower rate due to their larger size (there's even a graph! See, science!). Most conclusively, if you keep the moisture in the burger by putting it in a zip-top bag, both the McDonalds and the home made burger will mold and rot quite nicely (nastily?).

So, the take home message is twofold 1) McDonalds burgers are not bad for you because of mysterious mold-inhibiting additives or processing (they're bad for you for completely different reasons) and 2) Scientific testing of hypotheses can be informative! (This point is illustrated nicely below in a sign at the recent Rally to Restore Sanity and/or Fear in DC.)  Don't believe everything you read on the internet, folks!

The Case of the Mummified Burger

It's true - if you have read the internet (at least the gossipy, meme-ridden parts that I read) in the past week or so you have come across the case of the Mummified McDonald's Burger. The evidence so far in this case consists of several accounts of McDonald's hamburgers mysteriously failing to rot or in any way decompose after long periods of storage at room temperature. See examples here, here, and here. Conclusions that McDonald's burgers are full of strange chemical preservatives and don't actually contain any food have become so widespread that McDonald's actually issued an official response, stating that their burgers are actually made of 100% beef. Do McDonald's burgers actually spit in the face of normal decomposition, or is this a scare tactic used by those who aim to convince consumers to eat less fast food (an aim I support, I assure you)?

I, for one, think that McDonald's is probably not lying to us about the contents of their burgers, urban legends about worm meal aside. I think that a McDonald's burger is probably actually made of 100% beef, although it's probably full of processed meat scraps from factory farmed cattle that have been pumped with antibiotics and corn for most of their lives. Still, the FDA still calls that "beef," and it should rot, no?

I suspect that what's happening here is that the non-rotten burgers are full of salt and fat, two things that don't decompose quickly and tend to inhibit microbial growth. Add to that a very low level of moisture, and you have a mummified burger. Ancient Egyptians didn't rot, either, even though they weren't full of new-fangled chemical preservatives. Some Egyptian mummies were preserved with natron, a mixture of sodium carbonate and bicarbonate (aka baking soda) used to remove moisture from the bodies, and others were preserved by the hot dry environment alone. I would guess that a Mickey-D's burger has enough salt to preserve a measly quarter pound of cooked beef pretty well. Importatly, however, I don't have any evidence to prove this, so it's not a scientific conclusion.

What we need is a controlled experiment! Enter our heroes at Serious Eats Blog A Hamburger Today, where the Burger Lab is putting it's money where it's (and my) mouth is (are?) by testing burgers of the same size and shape, some from McDonald's and some home-made, to see if they rot any differently. I eagerly await the results of this experiment. We'll see if there is something magical about the McDonald's hamburger that preserves it so well, or if we're going to have to come up with a less simple way of explaining to consumers that fast food is bad for you.