Welcome to brain Stuff, a production of I Heart Radio, Hey brain Stuff, Lauren vogebam here. Though today they're available year round in many parts of the world, apples were once strictly a fall time treat, and they remain one of the cornerstones of seasonal cooking in the United States. If you live in the US, your apples probably didn't travel too far to reach you. Only five percent of
the apples sold in the US are imported. The rest are grown domestically intemperate states like Washington, New York, and Michigan. But the apples in grocery store bins aren't usually sold when they're harvested. They might have been in storage for up to a year. So unless you take a trip to your local orchard, how do you know whether the apples you're buying are actually fresh? And if they're not
doesn't matter. A picture yourself walking down the aisle of your local grocery storm, strolling past piles upon piles of shiny, round apples. How do you know which ones to buy? Start by looking at the surrounding apples. For the article this episode is based on, has to Fork Spook by email with Jessica Cooperstone a food scientist at the Ohio State University. She said apples are climatric fruit, meaning the fruits continue to develop and ripen after they're removed from
the tree. Apples and their climatric ilk are highly sensitive to ethylene, the chemical compound that causes fruits to convert starchy cellulose into sugars, otherwise known as ripening. As they ripen, apples release more ethylene, which bleeds the fruit around them to ripen faster as well. In this way, one bad apple really can spoil the whole bunch. Other climatric fruits include bananas and avocados, while non climatric fruits include things
like strawberries and cherries. Since ethylene is pretty much a universal chemical symbol for ripe in climactric plants, it will even help ripen fruit across species. You can harness its power for yourself. Try putting a hard avocado in the same bowl as an apple and see how much quicker
the avocado ripens. Apple harvesting season is very short, about two months in the fall for most varieties, so in order to extend their lives after picking, apples are usually treated with a gaseous compound that blocks ethylene, and that's not all. Cooper Stone explained by modifying the environment that apples are stored in, mostly by modifying oxygen, carbon dioxide, and ethylene and keeping apples cool, certain varieties of apples
can be stored for up to one year. This is a really impressive feat of post harvest storage technology, and most of this development happened in the first part of the twentieth century. It's called controlled atmosphere storage. When apples are exposed to less oxygen and more carbon dioxide than what's found in the air, they in a sense go to sleep and don't finish the ripening process, so these
apples won't spoil. The exact combination of gases and temperature necessary to do this varies with the type of apple, perhaps unsurprisingly, the types of apples that can handle this process, like Fuji, Gala, Granny Smith, Honey, Crisp band Red Delicious, are the ones you're most likely to encounter in a mass market grocery store, and not every apple is equally preservable. Some fragile skinned types well like Courtland, Jonah Gold and Crispin,
should be eaten soon after they're picked. Otherwise they might become too soft and mealy for eating fresh, though they'd still be fine for many cooking applications. These days, science is stepping in to create new types of more resilient fruit, and take for example, the ruby frost apple, which was
developed by Cornell University especially for winter time consumption. These hybrids, crossed between brayburn and autumn crisp, are bred to reach peak sweetness in mid to late January, months after they're harvested. While some new types of apple like the Ruby Frost are the product of careful selective breeding, others are the
result of more modern genetic engineering. Arctic apples, which are genetically modified to resist browning, became one of the first GMO fruits to be approved by the U. S Department of Agriculture. There isn't a way to tell when an apple was picked just by looking at it in a grocery store, and in some ways it doesn't matter, but you still want to make sure the apples you buy will be tasty and ripe. A touch is a better indicator than color, since the colors that signify ripeness can
vary pretty widely. The apple should be firm, but not hard, you can press it with your thumb to see, and it shouldn't have bruises. Once you bring apples home, store them in a cool, humid place like your refrigerator's crisper drawer. But even if you do wind up with an aging or overly ripe apple that's lost its firmness, it still has uses a cooper Stone set. If I've kept apples for a long time and find they're shriveling enough that I don't want to eat them fresh, I'll use them
in a cooked application. A slightly wrinkly apple may not look as pretty as a freshly picked one, but both are totally safe to eat, and the wrinkled ones are great and hot oatmeal or baked into a pie. However, you definitely want to avoid apples that have mold growing on them or that have begun to use liquid. But your chances of getting food poisoning from an apple are slim but not zero, so it's important to wash your
apples before you chow down as well. Once your apples are out of storage and thoroughly cleaned, it's time for some good old fashioned fall cooking. Any time of year, from caramel to crumble to cider. And cake. The possibilities are all delicious. Today's episode is based on the article your grocery store Apple could be a year old, but That's Okay on how stuff works dot Com, written by
Joanna Thompson. Brain Stuff is production of by Heart Radio in partnership with how staff works dot Com, and it's produced by Tyler clang Be. Four more podcasts from my heart Radio, visit the a heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.