The female Humulus lupulus, the hop bine (not vine), produces soft cone-like fruits (often mistakenly called flowers) that provide a bitterness and variety-specific aromatics to a beer. Pale ales were made possible by the use of hops. Darker beers are made from malts which have gone through the same process as searing steak or toasting bread, known as Maillard reactions. These are heat-driven oxidative reactions between reducing sugars and amino acids, and the products are acidic. This acidity inhibits the growth of many potential beer spoilage organisms. Pale malts produce an extract too basic to inhibit these organisms significantly without additional help. There is a natural preservative effect from some of the compounds in hops, particularly a class of acids called iso-alpha acids, represented by humulone.
The rigid structures of these molecules combined with the large hydrophobic and hydrophilic areas seriously disrupt the integrity of the lipid bi-layer cell membranes of Gram-positive bacteria. The measured “Bitterness Units”, called BU or IBU (“International” thrown in for no apparent reason) measure not only the quantity of these compounds present in a beer, but also the relative bitter flavor level. The minimum level for bacterial inhibition is 17 BU. This is approximately the lowest level found in English Pale Ales or Bitters or European pale lagers.
Why So Hoppy?
Pre-Prohibition there were more breweries per capita than even today. Most of these brewers had several offerings, and many varieties of beer were represented. Prohibition led to bootleg distilled products mixed with something sweet being the beverage of choice. After the repeal, when the breweries returned, an entire generation of beer drinkers had been lost, so the largest market was for “beginner beers”. They became almost the entire market and led to consolidations into the 1980s. After World War II, American servicemen were stationed overseas and fell in love with flavorful varieties of beer. Returning to the States, they began seeking out these products, but the imports were usually stale. Home-brewing became an alternative. Unfortunately, the home-brew industry of the time had ingredients of dubious quality and freshness. The only readily available fresh hops were those grown for their yield over traditional flavor profiles, most notably varieties like Cascade which had a strong, distinct flavor. The fact that these hops covered up a lot of other sins in homebrew led to more and more additions. Stronger beers keep better as well, so the trend in alcohol was upward. These home-brewers who had gotten accustomed to overt, strong, hop-dominated beers became the first microbrewers, producing uniquely American beers.
Why India Pale Ale?
The only historical style which was remotely close to these strong, hoppy beers was called an India Pale Ale. As the home-brewing community was becoming the fledgling craft brew industry, they brought their ideas along. The home brew community was at the time far more enthusiastic than scientific. Their competitions were judged by style and the beer’s adherence to that style is a significant part of the scoring. Unfortunately, the original style parameters were never well studied. No spider graphs or statistical analyses of extant style examples were used. The style guides were instead written by the “Meh” method, as in “Meh, the last beer I made that I called a ‘whatsit’ fit these parameters” and “Meh, Fred said this in his book”. When the Great American Beer Fest adopted home-brewing style guidelines as the basis for judging a category, “the scoring by fit to category” system basically required competitors to conform to the Meh guidelines to win a medal. All beers were assumed to be representative of some historic style. The actual characteristics of the historical style were never analyzed in any real scientific way. Much like Heisenberg’s Uncertainty Principle, the act of judging by Meh standards made those standards the de facto, regardless of their original accuracy.
What was India Pale Ale?
The historical India Pale Ale was, in fact, a type of stock ale, a high-gravity brew “concentrate” that was later blended or diluted for drinking. Stock ales generally weren’t consumed undiluted in England until they had aged for a couple of years to mellow the hops to a more balanced flavor through slow oxidative reactions. The stock ales destined for India were made with more hops so that it could survive the trip across the equator in a wooden cask aboard a wooden ship with SOME flavor intact after it was diluted. Luckily the same rapid oxidation effect from travel that ruined weaker beers served instead as rapid aging and improved these stronger beers. The piney hop-dominated creation that Americans call IPA is almost, but not quite, completely unlike the historic example. The name stuck anyway. Sadly it wasn’t even the first time a reference to India had been misapplied to something or someone indigenous to America.
Why the Bitter-Face?
Most human sensory interfaces like sight or hearing are pretty universal. Sound vibrates an eardrum or light strikes rods and cones, and the brain creates a model to interpret this input in very similar ways in all people. Blue is blue and the key of G is the key of G to the vast majority of humans. This is not so with smell and taste. Most of what we taste is actually smell with the exception of sweet, bitter, salty, umami, sour, etc. There are many genes coding for what we perceive as “bitter” and which aromas we are sensitive to. This is why, for instance, people have vastly different ideas of how Brussels sprouts or cilantro tastes. Our sensory thresholds for flavors we experience increases with exposure. Add to that initial difference behaviors such as smoking or vaping which significantly diminish these senses. This is where the “love it or hate it” factor comes in. The flavors and aromas are actually different to different people, the coffee-drinking hookah bar hipster with bitter genes that don’t correspond to iso-alpha acids finds the level of bitterness and aroma of an American IPA pleasant and flavorful, with a refreshing intensity of flavor. However, the non-smoking bitter-sensitive person who has white toast and Coca-Cola for breakfast finds the same beer unpleasantly overwhelming. It’s a good thing that craft beer has so much variety, if you don’t like IPA, it’s rarely the only choice. If you love a good hoppy IPA, rest easy. We American brewers will still be making lots of them for the foreseeable future.