Since orange juice is often stored for long periods of time, certain steps must be taken to ensure it's stable for that long. To do that, it might be heated or stripped of oxygen — both ways are effective means of stretching the expiration dates on OJ. Unfortunately, both methods also strip the juice of much of its flavor. In order to get the flavor back, most companies use flavor packs to make the orange juice taste like, well… orange juice. These flavor packs are often designed by the same companies that create perfumes, and though they technically are made up of orange essence and oil, they do contain chemicals like ethyly butyrate, as well as esters and aldehydes. Basically, they take all of the natural substances lost from the juice during the processing, break it down into simple chemical components, and then put it back into the juice when it's ready to be sold. The best way to avoid all these additives? Skip the store-bought stuff and just make your own.