by Carla Jean

Created on: March 03, 2009   Last Updated: March 04, 2009

A few years ago, if I were a game show contestant and asked the difference between an ale and a lager, I couldn't have told you, not even for a million dollars. I simply didn't know and didn't know that I needed to care. But as my drinking palate expanded and my vocabulary grew, I knew I should probably get to the bottom of this very fundamental question.

Almost all beer (with the exception of a few crazy ones) falls under the category of being an ale or a lager. Like most of the organisms on the planet can be divided into Animal or Vegetable, lagers and ales are super-categories for beer. (If you're interested in the pedigree,

The Fermentarium has a great chart of all the beer styles)

But what's the difference between the two? The stock answer, repeated with a memorized monotony by brewery tour guides, is that ales are top fermented and lagers are bottom fermented. Which, to anyone but a beer geek, means absolutely nothing.

Luckily, I went on a brewery tour at the Stone Brewery in Escondido California and I was fortunate enough to have a brewer set me straight. He was an excellent guide, with a bit of humor and a lot of science. He got as geeky and technical as you'd ask him to, while still being able to explain things in a clear way even to a novice.

I learned the real meaning behind the two basic beer terms, and I hope that this is the last explanation of the difference that you'll ever have to read.

When beer is brewed, there's a lot going on. But the one thing that makes beer special is that it's made by animals little molecules of yeast. When yeast is added to the sugars and grain mixture (called the wort), the yeast cells devour them and produce waste in the form of alcohol and carbon dioxide.

It is the same process metabolically as what happens in our muscles sugars get converted to other molecules as they get used up only in our muscles the byproduct is lactic acid, the stuff that makes it hurt to run too hard. Can you imagine if our muscles produced alcohol as a byproduct instead? You'd get drunk after running a few miles

Anyway, when the yeast is doing its job munching away at sugar molecules and burping CO2 and alcoholic goodness, the yeast cells grow, reproduce and generally have a party. As the process continues, they begin to clump together or "flocculate."

So, the tiny yeast particles stick together in a similar way that fat, fluffy snowflakes form, by grabbing onto one another. In fact, flocculated yeast looks a lot like the snow in a snow globe, if

• 1
• 2
• Next Page >>