Why You Can't Buy Fresh Olives (IMAGE) American Chemical Society Caption Olives grow on trees. So why have you never seen a fresh, tree-ripened olive in the produce section at the grocery store? Why are they always swimming in salty brine? Oh, and did you know that black olives are actually green? Watch as this video from Reactions breaks down the chemistry of these salty, oily stone fruits: https://youtu.be/oStoeHntfG8. Credit The American Chemical Society Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.