Today’s picture was snapped during lunch at one of the many taquerias in San Diego. This one just happened to have a giant gumball machine.
To be clear, the machine was the giant part. The gumballs were normal sized. I suspected they were there mostly for decorative value, as the pink ones looked a bit sun-bleached. How old could they be? Perhaps it doesn’t matter. According to the International Chewing Gum Association, chewing gum doesn’t spoil and isn’t even required to have an expiration date in most of the world.
Perhaps the reason for chewing gum’s shelf life is because it is made mostly of food-grade polymers. The polymer family of molecules is wide and varied, running the gamut from cellulose and nucleotides all the way to vulcanized rubber and Perspex. But that part’s unappetizing without the addition of the minty or fruity flavorings we know so well, and the colorings to tell us which flavors to expect.
The flavor compounds will probably break down after a few months. Dyes break down a bit more slowly, though Red #3 is said to fade quickly when exposed to light. Some bakers have added this dye to icing and found it to fade away as quickly as overnight.
That would explain why only the pink ones look sun-bleached and the other colors look fine. So perhaps those gumballs haven’t been there as long as appearances may suggest.