The fruit that is not food yet
Pick an olive off a tree and bite it. You will spit it out. Everything that happens between the branch and the jar is the actual story.
Almost every fruit we grow can be eaten where it hangs. The olive cannot. University of California Extension names the culprit: “Olives picked off the tree contain a very bitter compound called oleuropein.” Getting rid of it is not cooking; it has its own name — “the processes that remove the bitterness are called curing, which leach out the water-soluble oleuropein compound from the olives to make them palatable,” and “the most common curing processes include water, brine, lye treatments and dry salt.” Weeks can pass between the tree and the table. The United States government agrees, in the driest possible words: its grade standard begins by saying that canned ripe olives “are prepared from properly matured olives which have first been properly treated to remove the characteristic bitterness.” Nothing about an olive is ready when it is picked.
Basis: UC Cooperative Extension, Master Food Preservers of Amador/Calaveras County (UC Agriculture and Natural Resources), “Curing, Preserving and Eating Olives!”: “Olives picked off the tree contain a very bitter compound called oleuropein. The processes that remove the bitterness are called curing, which leach out the water-soluble oleuropein compound from the olives to make them palatable. The most common curing processes include water, brine, lye treatments and dry salt.” USDA Agricultural Marketing Service, “United States Standards for Grades of Canned Ripe Olives,” §52.3751 Product description.
Now the part that makes people put down the can and read the label. Those glossy black olives — did they grow black? USDA’s standard sorts canned olives into two types, and it sorts them by what was done to them. “Ripe type olives are those which have been treated and oxidized in processing to produce a typical dark brown to black color.” And the other kind: “Green-ripe type olives are those which have not been oxidized in processing; which range in color from yellow-green, green-yellow or other greenish casts; and which may be mottled.” Read those two sentences side by side and the black in the can stops being a description of ripeness. It is a description of a process — a treatment, and air.
Basis: USDA Agricultural Marketing Service, “United States Standards for Grades of Canned Ripe Olives,” §52.3752 Types of canned olives, paragraphs (a) Ripe type and (b) Green-ripe type, quoted in full.
The same standard quietly tells you what it is not about, and that sentence is worth reading twice: “Canned olives which are not oxidized in processing and which possess tan to light bronze color indicative of preparation from olives of advanced maturity and commonly referred to as tree-ripened or home-cured are not covered by the standards in this subpart.” In other words, an olive left to ripen on the tree and cured at home comes out tan or bronze — and falls outside the rulebook entirely. The familiar supermarket olive, uniform and black and shining, is a manufactured colour; the one the tree makes on its own is not even in the document.
Basis: USDA Agricultural Marketing Service, “United States Standards for Grades of Canned Ripe Olives,” §52.3751 Product description, final sentence, quoted in full.
So why does one state hold nearly all of the country’s olive acres? Two facts sit next to each other and are tempting to staple together. UC Extension says the olive tree is “native to the Mediterranean,” grown there “in rocky soil without irrigation.” And the state that leads USDA’s olive table also leads its grape table — another crop with deep Mediterranean roots. Tempting, but this page will not pretend that a resemblance is an explanation. No source quoted here documents why American olive growing ended up concentrated as it is, and a page about official statistics should be clear about the difference between what the numbers show and what they merely suggest.
※ A hypothesis is an idea that isn't proven yet.
📊 Sources for the rankings mentioned in this note (links to the original data and retrieval dates) are on each quiz page below.