Why does orange juice need to be refrigerated but oranges don’t?

Question

A breakfast musing

In: 161

Answer 1

**TL;DR:** ***Air greeblies.***

Think about how an orange grows.

It starts off as a tiny lower bit of a flower. The petals then fall off and the orange tree starts pumping water and starch and other nourishing stuff into it. So it grows, and forms a peel, with little bits of starchy water (and seeds too, if not seedless) safely stored in it and completely away from air. All the time this pumping and growing takes place, the inside of the orange is sealed from the outside air, so no microbes or bacteria or yeast or other floaty or fly-delivered greeblies like that can get in there.

Then, it ripens and the starches convert to sweet sugars, still protected from all those air greeblies. And greeblies LOVE sugar. And if they get into sugar water, they multiply and spoil it. Especially if it’s warm.

You pick your orange and juice it in a factory. Suddenly, even if you try not to, maybe that super-sugary-water is exposed to air! Now there’s no peel to protect that wonderful sugary water from the greeblies, so maybe greeblies got in!

So, in case the juicing process causes exposure to greeblies, they ask you to refrigerate it, because greeblies don’t grow as fast in cold sugary water and so it won’t spoil so quickly. That’s even more important when you break the seal on it by pouring your first glassful in your greeblie-infested home.

Whole oranges? If they have greeblies inside, you’ll know by the soft brown or moldy spots. But oranges don’t get those quickly – they’ve evolved not to. So they kind of visually tell you they’re still safe because nobody broke their peel seal.