Hop Shift

(Illustration by Michael Byers)

Last spring, former Harpoon brewer Steve Theoharides was talking about the brewery’s new session IPA, Take Five. It’s a well-done example of the style, vividly hopped but not bitter, low in alcohol but not thin. Developing the beer had been a challenge. Theoharides was working with potent American hops, and they were contributing too much bitterness. Beer gets its bitterness primarily from hops added at the beginning of the boil; they get flavor and aroma from hops used later in the boil. To dial back the bitter pop, he kept trying new batches with less and less of those first-addition hops until he wasn’t using any at all. “We found that there’s significantly more utilization in later additions than has been traditionally thought,” he explains. “So we skipped over the early addition altogether.” Theoharides didn’t use a single hop cone in Take Five until 20 minutes before the end of the boil.

This may seem like a random, quirky factoid about one of the thousands of beers made in the U.S. today. In fact, it’s the tip of a very big and interesting iceberg. Brewers all over the country have gone through a similar process in the beers they’re brewing, not just session IPAs, but pales and IPAs and double IPAs—any hoppy ale, basically. Like Theoharides, they were chasing those incredibly lush aromas and flavors American hops produce, without the bitterness. And like Theoharides, that meant using less and less of the hops from the start of the boil and more and more at the end.

In Portland, Oregon, Breakside Brewery’s Ben Edmunds started retooling the way he made hoppy beers a few years ago. (It apparently worked; Breakside’s IPA took gold at the 2014 Great American Beer Festival [GABF] in the American IPA category.) Like Theoharides, Edmunds was also getting too much bitterness. “So, we started peeling away, peeling away,” he says. “And the beers all got better.” At Maine Beer Co., very near the other Portland, co-founder Daniel Kleban arrived at the same place, too. “Anything before 30 minutes is an afterthought,” he says. “I start with my whirlpool and other late additions, because that’s where you’re going to drive all your interesting flavors and not extract a tremendous amount of bitterness.”

Not to put too fine a point on it, but in the history of brewing no one has ever approached beer this way. Brewers have always front-loaded their beers with bittering hops. Even in beers that aren’t notably bitter, the bulk of the hops goes in at the start of the boil. It’s how you achieve balance with the malt, and it’s how you protect your beer against spoilage. Kleban laughs when he talks about it. “If you pick up a textbook and read it, this technique doesn’t exist. I think the mindset of brewers who operate in this space—American-style, hop-forward beer—it’s certainly different from how I learned to brew. But it’s the only way you can do it.”

In different countries (or sometimes regions), brewers share an approach to brewing that the rest of the world
regards as at best weird and at worst dead wrong. Czech lager breweries all use an old, antiquated mashing system that other countries have mostly abandoned. Germans brew to the peculiar dictates of a 500-year-old law. The English make beer that must be kept in a pub cellar to finish carbonating and that goes bad hours after it’s tapped. And the Belgians—well, a good half the stuff Belgians do cause brewers elsewhere to shake their heads. You could say national brewing tradition consists of techniques the rest of the world eschews.

Thanks to this oddball hopping technique, they may be saying that about brewers in the United States now.

Hopping Backward

Hoppy ales are so popular that it’s hard to remember a time before IPAs—even though their popularity only started peaking in the mid-2000s. (Until 2011, pale ales were the best-selling style in the U.S.) By that time, breweries had been experimenting with super-hopped beers for a decade, and drinkers had begun to realize that what they liked was not brute bitterness, but all the exotic flavors and aromas American hops produced. When drinkers describe the qualities of “hoppiness”—grapefruit, pine, apricot, mango, cedar—they’re pointing to aromas and flavors, not IBUs. Vibrancy is innate to American hops, but this shift also coincided with the introduction of new breeds of super juicy hops, starting with Citra in 2007, that further encouraged the shift.

Brewers wanted to extract that juiciness, which meant using hops later in the boil when the heat doesn’t have time to drive off delicate oils and volatile compounds. But they found the beers they were making were far more bitter than the traditional algorithms suggest they should be. They didn’t want to sacrifice the flavor and aroma they were getting from the late hops, so they did the only thing that made sense: cut down the bittering hop additions. At a certain point, the percentage of hops that went in at the start of the boil got so small, it flipped the way these brewers thought about beer.

Kleban explains this transition: “It used to be bitterness—people equated hoppiness with bitterness. So you’d start with your bittering addition, and whatever you had left at the end, you’d just throw in. That’s the way recipes were designed; I’m going to derive X IBUs from my boil addition, I’m going to derive X% from my mid-boil addition and then X% from my late additions. Then you did the math and filled in the blanks. Now it’s thinking about it in the reverse order; that’s been the paradigm shift in brewing hoppy beers.”

A Whole New Map of “Hoppiness”

Along the way, breweries made a surprising discovery. To become bitter, alpha acids must be chemically altered (“isomerized”) by heat. Because hops added late in the boil (or afterward, in the whirlpool) aren’t exposed to heat very long, everyone assumed they weren’t providing much in the way of bitterness. That’s what it says in the textbooks Kleban referenced.

Brewers making hoppy American ales have discovered otherwise. “I think all the formulas out there are nonsense; it’s simply not true,” Edmunds says. “We really need to retool what we use as our utilization for whirlpool and late kettle additions across the board for all the beers. There’s a huge amount of flavor and aroma pickup—of course—but the utilization we calculate is about 12 percent.” That last figure is a technical number that relates to the amount of bitterness hops contribute during isomerization. Added at the start of a 60-minute boil, hop utilization is around 30-35 percent, so 12 percent is substantial.

Theoharides—now at Zero Gravity Craft Brewery in Vermont—echoes Edmunds, getting a similar utilization. “We were extracting some bitterness on the order of 13, 14 percent utilization, which is pretty wild.” And Kleban points out why brewery after brewery keeps making this discovery. “Even if it’s only 10 or 15 percent isomerization, 10 or 15 percent of a ton of hops can add up to a lot of IBUs.” For hundreds of years, brewers paid no attention to the IBU pickup in their late addition hops, believing they contributed at most 2 percent utilization—but that’s because they were only using a trivial amount.

Once they started brewing this new way, putting most of the hops in at the end of the boil, brewers started making other discoveries about the quality of bitterness. Kleban argues that some hop varieties seem to pack more punch than others. “Not all IBUs are created equal. If you’re using a hop you know has a jagged, rugged bitterness to it, you might want to [lower] the IBU. On paper, it says it’s going to be 10 IBUs, but I know it’s really going to be perceived more like 15, I’m going to dial back the volume a little bit.”

Kleban is not alone in thinking this way. At Breakside, the brewers now divide their hops up into two categories, “punchy” and “soft.” They think of hops like Centennial, Columbus, Chinook and Simcoe as punchy, while Citra, Galaxy, Mosaic and El Dorado are soft. Edmunds acknowledges this isn’t scientific, but it has guided the way they use them in the brewing process. “Over time, we’ve learned which hops we like better as kettle hops, which ones we like better as whirlpool hops, as dry hops. Comet, only a dry hop. Amarillo, El Dorado, Citra are great whirlpool hops. Centennial, Cascade we like better as a 10-minute hop.”

Finally, it’s important to acknowledge that the lines separating hops’ aromatic, flavoring and bittering elements are not clean. Saturating a beer in citrus flavor may enhance the sense of bitterness. Ardent Craft Ales in Richmond, Virginia, makes a line of hoppy ales. Brewer and co-founder Kevin O’Leary emphasizes this point. He gives an example of a double IPA he’d recently brewed. “The calculated IBUs are lower than our IPA. But our customers, beer geeks around Richmond, were saying, ‘Whoa, this is a super hoppy beer.’ There was a perceived bitterness because of the flavor and aroma.”

Putting the Pieces Together

So how does this backward-hopping work? “Bottom line,” Edmunds says, “you have to start with a very clear flavor profile of your hops in mind and work backwards.” At Breakside, the brewers think of hop additions by type and weight, not potential IBUs. They begin with their whirlpool addition, which usually comes in at something like 1.5 pounds per barrel (adjusted for the beer’s gravity). This addition is added after the wort is taken off the flame, in a vessel originally created to remove the particulates from wort. Whirlpools weren’t originally designed for hop infusions, but that’s how Americans now use them.

RELATED: Hop Delivery Systems

Next Edmunds considers his 10-minute addition, which usually runs about a pound per barrel. He calculates the IBUs these two infusions will produce (using his rejiggered formula) and only then does he think about bittering hops. “Those 60-minute hops are basically for kettle performance,” he says, referring to the way in which hop oils stifle foam. That addition will typically contribute only 5-10 IBUs to the beer. To emphasize the point, he gives an example. “I made an IPA today on the three-barrel system [93 gallons] where the 60-minute addition was 1.1 ounces.” That’s the kind of 60-minute addition you’d expect to see in a 5-gallon homebrew recipe.

Dry-hopping, the process of infusing hops into just-fermented beer, is the final—and mandatory—step. This is where the aromatics really come to the fore, and it gives breweries a chance to add a clean, distinct hop note that is uninfluenced by heat or fermentation. Kleban seems to be speaking for hoppy ale brewers when he says, “In my mind you can’t make a hoppy beer without dry-hopping.” Techniques vary depending on the brewery setup, but the prevailing theory seems to be that a modest amount of hops for a shorter period extracts the most positive flavors without pulling off vegetal notes from the hop fiber. And here a “modest amount” is relative; 2 pounds per barrel seems to be common.

A New Tradition

One of the ways you know a country has developed its own way of brewing is when its brewers try to brew beers from other traditions. “Scottish ales” brewed in Belgium, for instance, bear little resemblance to the beers made in Caledonia. That certainly seems to be the case in the U.S. now. Brewers looking at a traditional Belgian beer wonder why it couldn’t be improved with a bit of zingy Cascades. “It’s not that Americans can’t make beers in a German manner; it’s that we choose not to very deliberately,” Edmunds says. “Whether it’s a pilsner that gets a pound and a half of whirlpool hop or our kölsch, which gets a whirlpool hop, it’s because we just want it.”

Traditions develop incrementally, so we sometimes miss them. But what’s happening in the U.S. is pervasive—from Portland, Oregon, to Portland, Maine, to Tampa, Florida. When Americans make a batch of IPA on a 10-barrel system, they might use 45 or 50 pounds of hops—and only 2 will go in at the beginning of the boil. Beer is by some accounts 10,000 years old, the use of hops about a thousand, and never in that time would it have occurred to a brewer to make a beer this way.

Put another way: Right under our noses, a new national brewing tradition is being born. And man, does it smell nice.

RELATED: Hop Delivery Systems