You're not supposed to milk that

The tainted milk scandal just keeps getting deeper and dirtier. The Economist has a column examining farmers' favorite topics — input costs and quality control. Why exactly would Chinese dairymen put a toxic plastic ingredient in milk?

But something fishy seems to be going on here. For one thing, melamine is not all that easy to dissolve into milk. For another, there’s been a worldwide shortage of melamine for some time now. Its price has shot up to more than $1,750 per tonne from $1,100 a few years ago.

So why use an expensive industrial chemical that’s in short supply to dilute a dirt cheap product like milk? The answer can only be that either some flaw rendered the melamine industrially worthless, or it wasn’t melamine at all.

You're heard that soylent green is made of people? The (anonymous) columnist suggests that Chinese milk products are made of something else that cows produce:

Urea may be not as rich in nitrogen, but it’s certainly a whole lot cheaper (around $650 per tonne). Sprayed into the milk at the temperature used to create a powdered product for baby food and confectionery, enough of the urea would be converted into melamine to show up in tests.

If that’s the case, where does the urea come from? Is it really fertiliser—or something else cattle produce in prodigious quantities? Perhaps that’s why the Chinese authorities are suddenly so keen to blame more hygienic melamine for all their woes.