Speaker 1: Welcome to brain Stuff, a production of I Heart Radio,
Speaker 1: Hey brain Stuff, Lauren vogebam here. Though today they're available
Speaker 1: year round in many parts of the world, apples were
Speaker 1: once strictly a fall time treat, and they remain one
Speaker 1: of the cornerstones of seasonal cooking in the United States.
Speaker 1: If you live in the US, your apples probably didn't
Speaker 1: travel too far to reach you. Only five percent of
Speaker 1: the apples sold in the US are imported. The rest
Speaker 1: are grown domestically intemperate states like Washington, New York, and Michigan.
Speaker 1: But the apples in grocery store bins aren't usually sold
Speaker 1: when they're harvested. They might have been in storage for
Speaker 1: up to a year. So unless you take a trip
Speaker 1: to your local orchard, how do you know whether the
Speaker 1: apples you're buying are actually fresh? And if they're not
Speaker 1: doesn't matter. A picture yourself walking down the aisle of
Speaker 1: your local grocery storm, strolling past piles upon piles of shiny,
Speaker 1: round apples. How do you know which ones to buy?
Speaker 1: Start by looking at the surrounding apples. For the article
Speaker 1: this episode is based on, has to Fork Spook by
Speaker 1: email with Jessica Cooperstone a food scientist at the Ohio
Speaker 1: State University. She said apples are climatric fruit, meaning the
Speaker 1: fruits continue to develop and ripen after they're removed from
Speaker 1: the tree. Apples and their climatric ilk are highly sensitive
Speaker 1: to ethylene, the chemical compound that causes fruits to convert
Speaker 1: starchy cellulose into sugars, otherwise known as ripening. As they ripen,
Speaker 1: apples release more ethylene, which bleeds the fruit around them
Speaker 1: to ripen faster as well. In this way, one bad
Speaker 1: apple really can spoil the whole bunch. Other climatric fruits
Speaker 1: include bananas and avocados, while non climatric fruits include things
Speaker 1: like strawberries and cherries. Since ethylene is pretty much a
Speaker 1: universal chemical symbol for ripe in climactric plants, it will
Speaker 1: even help ripen fruit across species. You can harness its
Speaker 1: power for yourself. Try putting a hard avocado in the
Speaker 1: same bowl as an apple and see how much quicker
Speaker 1: the avocado ripens. Apple harvesting season is very short, about
Speaker 1: two months in the fall for most varieties, so in
Speaker 1: order to extend their lives after picking, apples are usually
Speaker 1: treated with a gaseous compound that blocks ethylene, and that's
Speaker 1: not all. Cooper Stone explained by modifying the environment that
Speaker 1: apples are stored in, mostly by modifying oxygen, carbon dioxide,
Speaker 1: and ethylene and keeping apples cool, certain varieties of apples
Speaker 1: can be stored for up to one year. This is
Speaker 1: a really impressive feat of post harvest storage technology, and
Speaker 1: most of this development happened in the first part of
Speaker 1: the twentieth century. It's called controlled atmosphere storage. When apples
Speaker 1: are exposed to less oxygen and more carbon dioxide than
Speaker 1: what's found in the air, they in a sense go
Speaker 1: to sleep and don't finish the ripening process, so these
Speaker 1: apples won't spoil. The exact combination of gases and temperature
Speaker 1: necessary to do this varies with the type of apple,
Speaker 1: perhaps unsurprisingly, the types of apples that can handle this process,
Speaker 1: like Fuji, Gala, Granny Smith, Honey, Crisp band Red Delicious,
Speaker 1: are the ones you're most likely to encounter in a
Speaker 1: mass market grocery store, and not every apple is equally preservable.
Speaker 1: Some fragile skinned types well like Courtland, Jonah Gold and Crispin,
Speaker 1: should be eaten soon after they're picked. Otherwise they might
Speaker 1: become too soft and mealy for eating fresh, though they'd
Speaker 1: still be fine for many cooking applications. These days, science
Speaker 1: is stepping in to create new types of more resilient fruit,
Speaker 1: and take for example, the ruby frost apple, which was
Speaker 1: developed by Cornell University especially for winter time consumption. These hybrids,
Speaker 1: crossed between brayburn and autumn crisp, are bred to reach
Speaker 1: peak sweetness in mid to late January, months after they're harvested.
Speaker 1: While some new types of apple like the Ruby Frost
Speaker 1: are the product of careful selective breeding, others are the
Speaker 1: result of more modern genetic engineering. Arctic apples, which are
Speaker 1: genetically modified to resist browning, became one of the first
Speaker 1: GMO fruits to be approved by the U. S Department
Speaker 1: of Agriculture. There isn't a way to tell when an
Speaker 1: apple was picked just by looking at it in a
Speaker 1: grocery store, and in some ways it doesn't matter, but
Speaker 1: you still want to make sure the apples you buy
Speaker 1: will be tasty and ripe. A touch is a better
Speaker 1: indicator than color, since the colors that signify ripeness can
Speaker 1: vary pretty widely. The apple should be firm, but not hard,
Speaker 1: you can press it with your thumb to see, and
Speaker 1: it shouldn't have bruises. Once you bring apples home, store
Speaker 1: them in a cool, humid place like your refrigerator's crisper drawer.
Speaker 1: But even if you do wind up with an aging
Speaker 1: or overly ripe apple that's lost its firmness, it still
Speaker 1: has uses a cooper Stone set. If I've kept apples
Speaker 1: for a long time and find they're shriveling enough that
Speaker 1: I don't want to eat them fresh, I'll use them
Speaker 1: in a cooked application. A slightly wrinkly apple may not
Speaker 1: look as pretty as a freshly picked one, but both
Speaker 1: are totally safe to eat, and the wrinkled ones are
Speaker 1: great and hot oatmeal or baked into a pie. However,
Speaker 1: you definitely want to avoid apples that have mold growing
Speaker 1: on them or that have begun to use liquid. But
Speaker 1: your chances of getting food poisoning from an apple are
Speaker 1: slim but not zero, so it's important to wash your
Speaker 1: apples before you chow down as well. Once your apples
Speaker 1: are out of storage and thoroughly cleaned, it's time for
Speaker 1: some good old fashioned fall cooking. Any time of year,
Speaker 1: from caramel to crumble to cider. And cake. The possibilities
Speaker 1: are all delicious. Today's episode is based on the article
Speaker 1: your grocery store Apple could be a year old, but
Speaker 1: That's Okay on how stuff works dot Com, written by
Speaker 1: Joanna Thompson. Brain Stuff is production of by Heart Radio
Speaker 1: in partnership with how staff works dot Com, and it's
Speaker 1: produced by Tyler clang Be. Four more podcasts from my
Speaker 1: heart Radio, visit the a heart Radio app, Apple Podcasts,
Speaker 1: or wherever you listen to your favorite shows.