Flavor Fever: A New Swing at an OG IPA

By applying what we know now—using a grain bill that goes easy on the crystal/caramel malts and new yeast strains that overlay fresher, brighter aromas—we can achieve an updated throwback that lets us enjoy the best of both worlds.

Randy Mosher Dec 1, 2022 - 11 min read

Flavor Fever: A New Swing at an OG IPA Primary Image

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Like living organisms, the evolution of beer styles follows a principle called “punctuated equilibrium.” This principle states that while conditions remain unchanging, there is little evolutionary change besides random drift. However, when conditions do change, entities either adapt, radiate to fit changing niches, or get pruned back as unfit. With long-dormant American beer, real changes started in the 1970s.

The explosion of artisanal beer continues today, propelled by homebrewers and those who would try to make a living out of it. However, the earliest of these beers were inspired by European ones—especially British ales. Perhaps it’s an expression of the American character to turn a glass full of inspiration into something new and different, but these beers were not painstaking facsimiles of European standards. They were re-imaginings.

Anchor Brewing cast the die in 1972 with a total remake of their historic Steam Beer—switching to all-malt, tossing in some exotic crystal malt, then balancing it with the weirdest hop they could find at the time, a new variety called Northern Brewer. This outline became the rule for most pale ales, IPAs, barleywines, and others in the family ever since. In 1975, Anchor followed up with Liberty Ale—an American IPA, and the first in modern history.

However, let’s first consider the roots of the tradition. For a reference from IPA’s historical heyday, let’s look at an East India Pale Ale in George Amsinck’s 1868 Practical Brewings. It's a two-ingredient (SMASH) beer, using “New Burton white malt” and “East- and Mid-Kent” hops. This, he says, “was brewed by my instructor ... in olden times, when the Ales, from that locality, were perfect in every sense of the word.” This would put it somewhere around 1820 to 1830, maybe earlier. The specs, as best we know them:

  • Starting gravity was 1.067 and terminal was 1.031, giving a calculated ABV of just 4.8 percent—pretty rich, but a good foil for the hops.
  • Those hops were almost 13 oz (370 g) per five gallons (or five pounds per U.S. beer barrel) in the kettle with another 3 oz (85 g) per batch (or 1.2 pounds per barrel) as dry hops.
  • The high terminal gravity is explained by a “too hot” mash, as Amsinck says, at 165°F (74°C).
  • The beer would have been plenty bitter—a calculated 100-plus IBUs, even if you assume that Goldings in those days were only about 2 percent alpha acids.

Concerning Crystal/Caramel

Modern drinkers would recognize the beer Amsinck describes as an IPA, but there are clear differences from classic American IPAs. First, American IPAs used plenty of crystal or caramel malt. Although they had been around in Britain for many decades, crystal malts don’t appear to have been common in British pale ales until their gravities dropped precipitously, starting with World War I. My theory on its prevalence in the United States is that it was used to boost aroma in homebrews made from malt extract, which had been stripped of aroma by the vacuum-concentration process. Later, its use became habitual, needed or not. It’s bold, but it’s also a beast that can overwhelm a beer and cause it to age prematurely.

The reasons are in its chemistry. Because crystal/caramel malt is steeped whole at mash temperatures, a lot of the starch is converted into sugar before it goes into the roaster. This dramatically changes the chemistry compared to other malts. When roasting of these “steeped” malts begins, it’s syrupy rather than dry. This means the Maillard browning pathways are different—so instead of bready, toasty, and roasty notes, there’s a lot more caramel, jam, and toffee. There’s also a lot of caramelization, a somewhat different chemical process than the Maillard browning that dominates dry-kilned or roasted malts. A class of oxygen-containing chemicals called furans and furfurals brings different flavors: cotton candy, caramelized sugar, and burnt marshmallow. A chemical called beta-damascenone may add date/raisin/prune character, although it is also evident in over-aged hoppy beers.

These unique, intense flavors can take over a pale beer pretty easily. Drinkers thirsting for something really bold certainly got it with the first generation of American IPAs, but they’re a little heavy for modern tastes and contain a lot of unfermentables that fill you up. Even before the advent of the haze craze, American IPAs had been moving away from this rich style.

There’s also an issue with flavor stability. Beers with crystal malts—especially those in the middle of the color range—tend to age quickly, presenting a kind of “saddle leather” character reminiscent of sherry, but less pleasant. In some trials, one large Chicago craft brewer found the worst of this graceless aging was with 60 Lovibond (120 EBC) crystal. They always tried to avoid it afterward. As a general rule, Maillard-derived compounds have some antioxidant qualities. However, for complex reasons, some crystal malts contain reactive oxidative compounds that can transform amino acids into the aldehydes responsible for staling flavors once the reactive oxidant chemicals further break them down.


Modern pale ale malt is not really a blank slate either, with a bit of sharp, cracker-like toastiness. In stronger IPAs and especially doubles, it can be a little much. There’s no law stating that IPAs must be mostly pale ale malt, especially since we know paler malts were at least sometimes used in IPAs historically. Raw sugar from India and the Caribbean was sometimes used after 1846, which certainly lightens the body.

Reconsidering the Classic in New Light

So, what do we love about old-school American IPAs, and what could we improve upon? Their bold, mouth-filling flavors are great. Same for the in-your-face West Coast hops, with their pungent floral notes. What’s not to like? Well, for one, the aforementioned over-reliance on crystal malts, with their heavy flavors and poor aging. Also, those early “C-hops” (Cascade, Centennial, etc.) can be a little one-dimensional; it would be nice to overlay them with some more fun and modern fruity notes rather than replace them altogether.

On the grain bill, my recommendation is subtlety. Maybe mix down the pale ale malt with some lager malt. Consider a little crystal 20 for that clean, pure caramel flavor and maybe a pinch of crystal 80 for some old-school toasted raisin notes—but that’s just a suggestion. If you want a bit of sweetness, you can use a higher mash temperature and bump up the grain bill by a few percent to compensate for the lower attenuation and still hit the alcohol target.

Another thought: What if we could unlock some of the fruity, tropical hop aromas hidden in even the most utilitarian of hops? It turns out that we can. A new group of CRISPR gene-edited hops incorporates more plentiful and effective versions of enzymes that liberate thiols—those potent, sulfur-bearing aroma compounds found in grapefruit, passion fruit, and others. They're also present in many of the newer, highly desirable hop varieties.


The chemistry is a little complex, so bear with me. For various reasons, many flavor-active compounds in natural materials are most abundant in a bound form, attached to heavier molecules that make them less volatile and reactive and more stable. Normal fruity compounds such as monoterpenes, flavor alcohols, and others form glycosides—in dramatically higher quantities than in the free form that we can smell. Winemakers sometimes add glycosidase enzymes to liberate these bound chemicals and boost aroma—this works for fruit beers, too. Thiols, however, bind to the amino acids glutathione or cysteine. Normal brewing yeast strains have the gene for the beta-lyase enzymes that can break this bond—however, it is often not present in sufficient quantities, and beer fermentation can inhibit it. Gene editing can remove these limitations, resulting in a massive release of 3-sulfanyl-1-hexanol (3SCH, aka 3MH), which has intense grapefruit and passion-fruit aromas.

Chicago-based Omega Yeast now has two products, and one—Star Party, based on the workhorse Chico strain (originally from Ballantine Beer)—is perfect for our purposes. Besides Omega’s other offering, at least one other so-called “thiolized” yeast strain is on the market, and my guess is that others will be coming soon. To get the best results, there are some unusual brewing requirements, including mash-hopping and paying attention to the amount of bound thiol precursors present. Omega suggests Saaz for this, but Cascade, Calypso, Nugget, Perle, and Hallertau have high enough levels to work. Whirlpool hops add more potential.

Surprisingly, malt itself has a fairly high level of thiol precursors. Omega’s brewing trials in unhopped wort verified this, so these strains might be useful for lightly hopped fruit beers. Whatever yeast you use, be sure to pay attention to the instructions. Other than that, the fermentation procedure is perfectly normal.

All in all, it should be possible to use these new yeast strains to overlay fresher, brighter aromas onto a classic form of American IPA. Provided you lighten up the heavier elements of the grain bill, the result should be an updated throwback that lets you truly enjoy the best of both worlds.