Beer - The Light Refreshment Quotient
If in addition to being lower in alcohol and calories, your definition of light beer also requires something refreshing, crisp, and light in body and color, you can do that too. Berliner weisse, American wheat, and American lager are styles that should allow you to satisfy those requirements. Although more refreshing than the fuller bodied styles above, these styles can have plenty of flavor and character.
As wheat contributes a dry, crisp flavor, beers made with 20 to 50% malted wheat are typically refreshing. American style wheat beers are the most recent development in the wheat beer category. These beers vary greatly in the amount of wheat used, hop bitterness, and clarity. The original gravity typically ranges from 1.030 to 1.050 and the alcohol level is usually between 3.5 and 4.5% by volume. By using clean fermenting American ale yeast a brewer can produce a very refreshing summer cooler. Start with gravity at the lower end of the suggested range if you want a low alcohol wheat beer.
One of the most refreshing beer styles is the classic Berliner weisse. Berliner weisse is light-bodied, low in alcohol, and light and sparkling in appearance. The sour, acidic character of the style also adds to its refreshing nature. With original gravities between 1.026 and 1.036 and alcohol levels from 2.8 to 3.6% by volume, this is one of the lightest of all beer styles. Its acidity comes from the lactic acid bacteria used along with ale yeast for fermentation. Because of this, it's not an easy style for home brewers or microbrewers. Berliner Weisse is now a very rare style, even in its native Berlin. It is still brewed by two breweries in Berlin as well as a few in other cities in north Germany. It is also being revived by a few adventurous microbrewers in America. For brewers up to the challenge of dealing with lactic acid bacteria, experimenting with this style may eventually lead to the production of the ultimate lawnmower beer.
Finally, although it's a style generally disdained by home brewers and craft beer aficionados, you may want to try brewing your own version of American light lager. However, you can design yours to have flavor and a little more body than the popular mainstream versions. Part of the reason these beers have virtually no malt taste or aroma is due to the use of a high proportion of adjuncts. Adjuncts like corn and rice contribute fermentables but not much flavor or color. Thus, when you use a high proportion of adjuncts in place of malt, it cuts down on malt flavor and aroma. While corn does contribute a grainy sweetness to beer, rice is virtually flavorless. To get a little more malt character, you can design a recipe based on American lager and increase the proportion of malt. Use corn instead of rice as an adjunct and start with a gravity between 1.035 and 1.040. To limit yeast derived flavors and produce a drier beer, use a clean fermenting, attenuative American lager yeast. Wyeast 2007, St. Louis Pilsen Lager is a good example, although there are others that should work just as well.
Thus, you can see there are plenty of alternatives to those wanting to brew light beers with character. The style that's best for you will depend on your personal preferences and on how you define light beer. However, if you really want something that tastes like mainstream light lagers, you are better off buying it. It would be virtually impossible for home brewers to produce something so light in flavor, body, and color. The big breweries have put a lot of time, money, and effort into making beer that doesn't taste like beer and in convincing people that that's the way beer is supposed to be and they have done a pretty good job.