What is the main characteristic that differentiates light, heavy, and export beers?

The main characteristic that differentiates light, heavy, and export beers is alcohol strength. This attribute is critical because it directly correlates with the beer's overall body, mouthfeel, and flavor intensity. Light beers are typically brewed with lower alcohol content, resulting in a more sessionable and refreshing beverage that may appeal to those looking for a less intense drinking experience. Heavy beers, on the other hand, have a higher alcohol content, leading to richer flavors and a fuller body, which often includes more pronounced malt characteristics. Export beers, frequently designed for international markets, can vary significantly in strength but generally convey a well-rounded profile that balances alcohol strength with other flavor components.

The other attributes listed, such as color intensity, hop content, and type of yeast used, can certainly influence the character of a beer but do not serve as the primary differentiator among light, heavy, and export beers in the context of alcohol strength. Color may vary across beer styles but does not classify light versus heavy, while hop content primarily pertains to bitterness and aroma rather than the weight classification, and yeast type affects fermentation characteristics more than the categorization of beer strength.