Mark and his friend Anton recently cracked open a Coca-Cola that was bottled in 1956, back in the era of Chuck Berry, sock hops, and Marty McFly's first time travel destination. I don't want to totally spoil the results of their taste test, but let's just say that Coke appears to be even more impervious to the ravages of time than a McDonald's cheeseburger.
Cool fact: bottle caps in 1956 were lined on the inside with cork, like these caps for sale on Etsy.
Update: Mark and his friend Grace recently drank a bottle of Pepsi from 1935. I think it went ok because Mark emailed me this video.