German Beer: Worth a Scientific Look

[Aeternitas]

It only takes four ingredients to make a bottle of German beer: Hops, malt, water and yeast. Add anything else and you'll turn a national drink into a motley punch unworthy of consumption in the country's beer gardens.

Whether it's taken on tap, in a bottle or a multi-liter bucket, beer takes center stage on April 23rd -- Germany's day devoted to beer. On this day in 1516, Bavaria's then ruler, Duke William IV, passed the so-called "purity law."
While the name seems to imply an age-old method of enforcing Teutonic morals, the decree is actually the world's oldest food-related law and limits beer to just three ingredients: hops, malt and water. Yeast is a more recent addition to the list.

http://www.dw-world.de/dw/article/0,...558737,00.html

[Dr. Solar Wolff]

It seems that the definition of beer depends on where you are. I know that rice is put into some beer in the USA and Japan. The ancient Egyptians used wheat and some beers in the USA brag about using special types of wheat in their beer.