The Oxford Companion to Beer definition of
first wort hopping
is a method utilized to deliver additional hop flavor complexity to beer. It is quite probable that this method was initially discovered by accident when a brewer added hops to the kettle very early and then noted a flavor improvement in the finished beer or at least an increase in bitterness. First wort hopping was a common practice around the turn of the 20th century and was a practice used to increase hop utilization. The “rediscovery” research of this method was done in Germany focusing on pilsner style beer. The experiment was carried out in two German production lager breweries. A portion of the late kettle hops (the varieties Tettnanger and Saazer) were added to first runnings in the kettle and allowed to stay with the brew throughout the entire kettle program. The late hop/aroma addition was then omitted. In both test breweries, the beer brewed with the first wort hopping method was preferred organoleptically in blind tasting over the control beers. The panelists reported “a fine, unobstrusive hop aroma, a more harmonic beer, and a more uniform bitterness” when compared to the conventionally hopped reference beer. This would at first glance seem counterintuitive to most brewers since most have been trained to add hops for flavor and aroma toward the end of the kettle program, not before, believing most volatile hop aromatics would otherwise escape the wort. It is important to note that these beers were being critiqued in accordance with accepted and desired European hop qualities and would not likely be consistent with American hop characteristics or American craft brewer’s notion of finer hoppy qualities.
In practice, a substantial portion of the hop bill is added to the kettle or wort receiving vessel at the initial stage of the run-off. The hops are then allowed to steep in the wort for the entire run-off and then remain in the wort for the duration of the kettle program. In the case of the rediscovery experimentation, 30%–53% of the entire hop bill was utilized for this addition. The hop charge utilized an aroma variety that was originally slated as the final aroma/flavor addition and normally would have been added 10 minutes before the end of the boil. First wort hopping appears to take advantage of higher pre-boiled wort pHs, thus higher hop component solubility. More important, it acts to drive off lighter oils like myrcene as well as other oils associated with “hoppy” character in finished beer where these characteristics are not desired. De Clerk wrote about a method similar to this where hops are steeped in 122°F (50°C) water prior to being added to the kettle. This was also done to drive off unwanted light hop oils that might otherwise survive the kettle operation and be passed on to finished beer.
First Wort Hopping is practiced by a number of craft brewers and is applied to a full range of styles both ales and lagers. It is best suited for beers that call for a “European noble” hop presence or a deep yet subtle and refined hop flavor. This method is not suited for beers that require volatile hop oil presence or fruity hop aroma; in fact, it is a method that works to avoid these characteristics all together.
Modern brewers have limited hop boiling times to a maximum of 90 minutes to avoid harsh flavors that come from thermal breakdown of humulone to humulitic acids. First wort boiling obviously challenges this line of thinking by employing extended extraction times.