In this column, I've talked about many cultures of brewing. I've taken you from the stouts of Ireland to the lagers of Germany. I've described the yeasty, wild beers of Belgium and the inventive techniques of microbrewers in America. There is one final brewing tradition vital to understanding our world of beer, and that is the ale tradition of Britain.I'll never forget the story my mother told me as I was going abroad to Ireland about her time in England on her only trip to Europe. She told me about when she gagged on the warm, flat beer in the pubs, which was not cold and refreshing, as Americans expect. At the time, I was underage and not experienced with beer, so I didn't know about the heritage and tradition of this style of beer.

British ale usually involves the tradition of being served from a cask, a special type of keg that harkens back to the times when carbon dioxide wasn't available in tanks. Today, most brewers pump their beers with artificial carbon dioxide to create that bubbly beverage we all enjoy. In the past, brewers would place a small amount of sugar in the keg, which would be eaten by the yeast and turn into carbon dioxide. This tradition continues in the cask-ale system. Cask beer does not shoot off the keg as forced carbonated beer does-it is much weaker. To get the beer out, brewers must either use gravity or a special pump to pull the beer.

This is one of the classic aspects of a traditional British pub-you see the big hand pumps next to the tap lines. When someone orders cask ale, the bartenders must use all of their muscles to pull down this lever in order to let out the ale. Most of this ale will be served near room temperature to bring out all of the distinct flavors of the beer. This is something my mom found disgusting, but to the beer-loving Brit, it is the only true way to serve ale. I got my own chance to try the style when I flew from Ireland over to Edinburgh, Scotland. While it is strange, warm and flat, the beer had a unique characteristic to it: malty with a bit of a bitter herbal hop background. I had a few of these ales that night and never felt overly intoxicated-just relaxed, refreshed and thirsty for more.

Most of the beers in the kegs are session beers. These are beers that are below 4 percent alcohol to allow the drinker to have multiple drinks without getting drunk. They originally came out of the fact that the government taxes alcohol based on percentage, and workers needed a drink that would refresh them yet wouldn't get them drunk on their lunch breaks. So, session beers became the drink of the lower class, but after World War II, as Europe opened up for trade, the standard cold European lagers began to overthrow the cask tradition.

Cask ales were almost lost, but in the 1970s, a group of radical Brits started demanding their cask ales. Calling their group the Campaign for Real Ale, this group brought the cask back to the British pub. Members of this group stand by their beer, promoting cask ale as a true form of ale. The tradition has spread throughout the United Kingdom, with pubs from London to Edinburgh to Belfast, Ireland, proudly displaying their CAMRA seal of approval.

At this point, you are probably asking yourself why I haven't reviewed or talked about any specific beers. The fact of the matter is that I would love to; however, Americans don't produce this style well. We want our beer to usually be above 4 or even 5 percent alcohol. While some breweries do make cask ale, the British style is still lost on American brewers-they don't get the subtleties. If you want something close, most of the good beer bars in Boston, including Lord Hobo, Cambridge Brewing Company and Sunset Bar and Grill, have some American craft ale on cask. You won't get the full experience, but it will give you a hint of what the British find so appealing. It truly is something you need to try in England for the full experience.

So, if you ever find yourself abroad in Europe, be sure to book a Ryanair flight for 10 pounds to London and get yourself a bit of the bitter, as they would say. Cheers!