My first taste of Christmas this year involved Alton Brown’s Good Eats – and I learned something during the show which answered a long standing question I’ve had.
How and why does a single rotten apple ruin the barrel?
First, a little background from botany.org
In addition, ethylene promotes fruit ripening. Like many hormones, it does so at very low concentrations. Apple growers take advantage of this by picking fruit when it is not ripe, holding it in enclosed conditions without ethylene, and exposing it to ethylene right before taking it to market. This process is why we have newly ripened apples grown in temperate North America even in the spring and summer (apples ripen in the fall).
Ethylene acts as the signal for apples to ripen, but if that signal never reaches them, they can apparently be kept – unrefrigerated – for three or four months. The suggested method is to wrap each apple individually in newspaper, then simply store.
The trick is, you’ve got to be careful not to store a bruised fruit alongside your good ones – the bruise will throw off gouts of ethylene, causing your one bad apple to ripen the rest too early, and spoil the bunch.