Ever wonder why commercial orange juice—even the premium, not-from-concentrate, "100-percent pure" juice kind—tastes the same each time you buy it, but doesn't taste exactly like a freshly peeled orange?

Turns out there's a lot more to making juice than simply squeezing some citrus. As part of the  mass-production process, big-name brands like Tropicana, Minute Maid, Simply Orange, and Florida's Natural add  artificial flavouring in order to make sure your juice tastes consistent from carton to carton—and to make sure it tastes like oranges.

"It really rocks people's world to learn that most orange juice is not a fresh product," says Alisa Hamilton, author of "Squeezed: What You Don't Want to Know About Orange Juice" says in an interview posted on her website.

Pasteurized, not-from-concentrate orange juice takes up a lot of storage space. In order to keep it from spoiling without adding chemical preservatives, the companies "deaerate" (or strip the oxygen out of) the juice. (Another surprise: During production, deaerated juice often sit in million-gallon tanks for as long as a year before it hits supermarket shelves.)