The term “bitter ale” was created to distinguish them from lightly hopped mild ales, which were served relatively young, and the only alternative to porter and stout in the mid-19th century. Bitter ale helped introduce the “aromatizing” of beer as portion of hops were added late in the boil, something unknown to porter and stout. This attention to aromatic qualities may have inadvertently encouraged the hop farmers of England to concentrate even more on this aspect of their blossoming industry. Brewers soon began making variations of bitters, usually as a function of strength. India pale ale was the strongest, and kept for a long period of time prior to serving, while bitter ale was lighter, and served much less aged. By the end of the 19th century many brewers were making assorted bitters and mild, with IPA fading away. Even porter, the elephant in the room for over a century, had given way to mild, by now the most popular pub ale.
Throughout the 20th century, the state of ale changed dramatically, due to World War, changing taste and the heavy hand of corporate control. Rationing during wartime made gravities plummet, but this had the side benefit of brewers learning to make low gravity, but flavorful, ales. The remnant of this is “session” ale, defined as ale of up to 4 percent ABV. A staple among pub denizens, session ale is perfectly suited to ordinary bitter and mild on cask, a true expression of the brewing art. Bitters replaced mild as the most popular ale among the Brits only after World War II, and remains so today. The 1950s and ’60s though, saw a movement away from traditional real ale and towards mass-produced, bland, lifeless products. Plenty of folks were fed up with this trend, their grievances addressed and given life by the formation of CAMRA, the Campaign For Real Ale, in 1971.
CAMRA is a potent consumer group initially formed to restore the British tradition of providing “real ale” to consumers rather than the fizzy and flavorless renditions that were overwhelming the market. Real ale is defined as a natural, live product produced from traditional ingredients and left to mature in the cask (or bottle) via secondary fermentation. It is served from that container after brief conditioning at cool cellar temperatures, bright as a result of settling, with or without finings. It should have a gentle carbonation from priming and secondary fermentation. Dry hopping in the cask may be employed to enhance aroma. They are best served via hand pump or gravity, allowing a bit of air to bathe the ale as it is served, a condition that helps it breathe and enhance the subtleties of the product. While nearly any type of top-fermenting beer is served on cask as real ale, bitter is far and away the most popular. This should come as no surprise since English hops, malt and yeast are quite distinctive in their own right; reverence through simplicity. Each ingredient puts its stamp on a well-crafted bitter; chewy pale malt, floral, citrus, peppery hops and mild fruity, estery yeast are essentially all that is required to sculpt one. The bottled version of bitter may be known as pale ale, but just to thumb the nose at classification, there are plenty of cask pale ales and even bottled bitters.
In short, bitters as a style came into their own as a type of pale ale that could be served while quite young on cask as pubs moved away from aged, vatted ale and towards fresh “running” ales. They differed from mild, another running beer, by the higher hop rates. Often they used crystal malt and were dry-hopped. Much of this describes the modern versions. It is impossible to really classify them by anything other than their strength, and even this floats, since regional, or even neighboring, interpretations often vary significantly. Ordinary bitter runs between 3.4 and 3.9 percent ABV and are the quintessential session ale. Best bitter is the next strongest at 4 percent and higher, with extra or special bitter about 5 percent or more. Classification is largely considered frivolous by many, but like any other style or substyle, it gives the consumer a clue as to what to expect, something substantial or mellow. Beyond that, the classifications blend together. Bitters vary from golden to bronze, from moderate to aggressive levels of hops, and with varying degrees of late hop additions, with some being malty, others full-bodied and still others quite dry. House yeast adds its own accent and flair to the style, and British yeast is known to lend a fair amount of character on its own, not to mention its effect on attenuation. North American microbrewers make their own interpretations, and usually distinguish them from pale ales by deepening the color, adding some mouthfeel, and tempering the aromatic hop character. Some are spot on the English version, while others have an intentional American slant.
There is but one way to truly experience the charm of bitter, and that would be a prolonged, nationwide pub crawl of historic England. Until then, seek the bottles, cans and drafts that bill themselves as bitter or English pale ale, and plan that trip.