We might have been wrong about first wort hopping

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I haven’t been out there alone, suggesting first wort hopping, a process in which brewers add hops to wort as it is being lautered into the brew kettle, results in beer with a “finer” bitterness. Even though we can’t explain why. But the fact is I did write more than a few hundred words about it in For The Love Of Hops, based on evidence that was anecdotal as much as documented.

So it is with a heavy heart I report that recent research at Oregon State University finds “no perceivable sensory difference between the two treatments at a 95% confidence level.” Christina D. Hahn, a student at OSU, and Dr. Thomas Shellhammer, who leads the brewing science education and research programs there, presented the results as a poster at the International Brewers Symposium on Hop Flavor and Aroma in Beer last month in Corvallis.

That’s pretty much all you need to know. But a bit more about the study, for the record, and then some background. From the introduction:

“First-wort hopping (FWH) is a technique where hops are added to the first runnings of wort from the lauter tun before ‘kettle full’ and before wort boiling. This method exposes the hop material to wort at lower temperatures and an elevate pH for an extended period of time. Research related to FWH is limited and details surrounding the studies remain vague. Proponents of the technique suggest FWH produces a beer with improved bitterness qualities and use terms such as ‘smooth’ and ‘harmonious’ to describe effects.

“Research at the Oregon State University Pilot Brewery examined these claims by preparing two beers with the same mass of hops but varied in the timing of hop addition. The FWH beer was prepared by adding hops to the kettle prior to wort collection, while the reference beer was prepared by adding the hops to the wort at the start of boil.”

Although sensory evaluation found no sensory differences, chemical analysis indicated FWH could be responsible for positive foam characteristics (more research is needed). In addition, FWH can be utilized to reduce boil overs.

The limited research Hahn and Shellhammer refer to begins with a report in 1995 in the German brewing magazine Brauwelt about the “rediscovery of first wort hopping,” documenting that many German breweries implemented first wort hopping 100 years before and some experimented with mash hopping. The facts are that this didn’t occur only in Germany, but also in England and Belgium.

Jean-Marie Rock, long the director of brewing at the Orval Trappist monastery, says that Belgian breweries discontinued the practice in the 1970s. Rock began brewing in 1972, making lagers first at Palm Breweries and then for Lamot in Mechelen. A few years before he retired from Orval, Rock accepted an invitation from Steven Pauwels to collaborated on a recipe at Boulevard Brewing in Kansas City. Rock knew immediately he wanted to revive the defunct technique. To make the strong Pilsner, 8 per cent alcohol by volume with 30 bitterness units, they added two-thirds of the Czech Saaz hops they would use before the outset of the boil.

Rock was happy with the result. “It has a taste you don’t get when you use late hopping,” he said at the time. “You get an old taste. That is my opinion.” Pauwels, a native of Belgium who went to work at Boulevard in 1999, heard about the practice from other Belgian brewers as he learned his trade. He was told they wanted to keep the beer light in color, and the process allowed them to shorten the boil. “It wasn’t until later they found out the hop aromas carried over,” he said. “It seems like a contradiction. You’d think you’d get more bitterness and less flavor. It’s more subtle, almost crisper. Sometimes with late hopping it can get vegetative.”

Brauwelt reported that when two German breweries experimented with first wort hopping in 1995 they found the process resulted in beers with a finer hop aroma. Both breweries made two versions of Pilsner in very similar manners, including yeast pitching rates, brewing water, malt lots, and using Type 45 pellets. At Brewery A the first wort addition of Tettnanger and Saaz hops amounted to 34 percent of the weight. At Brewery B, which used only Tettnanger, it was 53 percent. In both resulting beers the first wort-hopped beer had more IBUs, 39.6 to 37.9 at Brewery A, and 32.8 to 27.2 at Brewery B.

Despite increased bitterness, the tasting panel described the first wort-hopped beers as more pleasant tasting and overwhelmingly preferred them. Gas chromatographic analysis indicated the conventionally hopped beers contained a higher level of hop aroma substances (particularly linalool), but panelists nonetheless described the first wort-hopped beers as having a very fine and rounded hop aroma and rounded hop flavor.

The authors of the study concluded, “… we recommend that first wort hopping be carried out with at least 30 percent of the total hop addition, using the later aroma additions. As far as the use of hops is concerned, the alpha acid quantity should not be reduced even in the case of an improved bitterness utilization. The results of the tastings showed that the bitterness of the beers is regarded as very good and also as very mild. A reduction of the hop quantity could result in the bitterness being excessively weakened, and the good ‘hop flavor impression’ could be totally lost.”

One more data point. Fritz Tauscher at Krone-Brauerei in Tettnang, Germany, uses a slightly different process. He adds 60 to 70 percent of his hops as he lauters wort into the brewing kettle. Tauscher, a seventh-generation brewer, conducts a decoction mash to make each of his beers, and lautering takes 120 to 150 minutes. He makes his first hop addition 20 to 30 minutes after runoff begins, and another five minutes before the onset of boiling. He adds hops shortly before the end of the boil, then again in the whirlpool.

His pilsner, with 34 to 36 bitterness units, is pleasantly smooth yet has a satisfying bite. He explained that initially he added all his first wort hops (what he calls “ground hopping”) in one dose. “I thought the bitterness was not so good,” he said. He opened his right hand, put it to his chin and slid it down his throat to his clavicle, tracking the path a beer would take. “It was, I’m not sure how you say it in English, adstringierend.” No translation was necessary.

How should we reconcile the differences between what Rock, and — well, lots of other people — perceives and the results at OSU found?

Over a beer.