system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does orange juice from Tropicana taste different from Simply Orange if they're both 100% Orange Juice?

I've taste tested both of these. They taste different, despite both saying 100% Orange Juice with no preservatives or additives.

Neither has pulp, and both bottles were bought on the same day.
gpt
Back in the day--maybe pre-1990s?--year-round fresh (not frozen, not concentrate) OJ was not as common and was more expensive. Then, some great new process was devised and it became more common and cheaper. With the new process, it's squeezed, then stored in vats for months at a time. This process caused it to lose flavor. So flavor is added before it is sold. Different brands have slightly different flavor processes so taste different. And these have a different flavor and consistency than genuine fresh-squeezed OJ. Go get some genuine fresh squeezed from Whole Foods or similar and you'll taste the difference.