Homebrewing

The is the air lock on a fermenting batch of Belgian Ale. It allows carbon dioxide to escape without letting germs in with a simple cap floating in water. Works like a charm.

I've been brewing at home for more than 13 years and learned something amazing not too long ago. I've been quite aware of the "German Beer Purity Law" called Reinheitsgebot for many years but it was only recently when someone pointed out the obvious.

My memory was that it only allowed for water, hops, barley and yeast. But put forward in 1487, it actually predates the discovery of yeast! (Note: Germany wasn't a nation-state either)

Yeast may have been first observed in 1680 by Leeuwenhoek (almost 200 years post Reinheitsgabot) but it wasn't until Pasteur in 1857 that it began to be understood (even later, after almost 400 years!)

For hundreds or thousands of years there must have been such a magic to beer. No wonder people are so superstitious.