Actually Nooner is exactly right. There are many types of beer all over the world that never see a barley kernel.
- Chica: a maize beer from South America made from unmalted maize
- Chang: Rice beer of Himalaya
- Kvass: Russian small beer made from rye bread and lemons
- Pissionia: Yuma native beer made from roasted wheat
- Pombe: East African beer made from millet
- Tesguino: Aztec beer made from malted corn
and a bunch of others, like roggenbier or sahti, where barley is just one grain or even an adjunct rather than the main grain. The type of beer we usually talk about on HBT is primarily barley, but Nooner's point is valid. All beer is not made with barley.
Chad
sources:
Radical Brewing, Randy Mosher, Brewers Publications 2004
Origin and History of Beer and Brewing, John P. Arnold, Wahl-Henius Institute of Fermentology 1911; reprint Beerbooks.com 2005