Nils Rettberg (1), Sarah Thoerner (1); (1) VLB Berlin, Berlin, Germany
Technical Session 14: Hops II
Tuesday, August 16 • 9:45–11:30 a.m.
Plaza Building, Concourse Level, Governor’s Square 14
In recent years, hop aroma has emerged as a key quality
characteristic of popular beer styles. Distinct late and kettle hop
flavor is a key attribute of pilsners, lagers, and non-alcoholic beers,
whereas appreciable dry-hop aroma is present in most pale ales, India
pale ales, and beer specialties. Driven by the growing craft beer scene,
hoppy beers are more frequently brewed at a large scale. Thus,
efficient raw material input, steady brewing technology with regard to
flavor formation, as well as consistent product flavor are highly
relevant. As a consequence, the instrumental analysis of hop-derived
odorants in beer advanced as a must-have analysis technique. Today, it
is not only used in a handful of upscale research projects, but
frequently requested for quality control purposes within breweries. The
requirement for suitable methods is, to name one specific example,
reflected by ASBC Technical Committee efforts to introduce a
standardized method for the analysis of certain hop aroma compounds in
beer. The increasing interest in hop aroma analysis surely requires
standard methods, but is this possible and accessible for a majority of
brewers in the near future? Unlike many other well-established quality
control tools, hop aroma analysis is rather complex. The unique flavor
of hoppy beers cannot be measured by analysis of a few marker molecules,
moreover it is the characterization of a heterogenic and complex
mixture of multiple odorants. The first reports on the analysis of
hop-derived volatiles from beer date back to the 1960s and 1970s (the
introduction of gas chromatography + mass spectrometry (GC-MS)), the
winding road of this research tool merging into quality control has
surely not ended yet. Overlooking today’s analytical capabilities, there
are multiple ways to extract, separate, detect, and quantify hop aroma
compounds from beer. Evidently, all have certain advantages and
drawbacks, steady improvement is visible. In the current study, several
methods (GC, GC-MS, GC-MS/MS) for hop aroma analysis are applied,
analytical data is compared and controversial data discussed. The
methods range from simple to sophisticated, aiming to give a preferably
comprehensive overview on the key factors in hop aroma analysis. In a
nutshell, different analytical tools deliver quite different results,
indicating that precise and simultaneous quantification of multiple
analytes strongly depends on the combination of sample preparation and
quantification procedure. The more complex or selective the sample
preparation procedure, the higher the demands for appropriate reference
standards, calibration, etc. Is hop aroma analysis ready for quality
control? It depends!
Nils (born 1983) is a trained as brewer and maltster. He holds a
diploma in biotechnology with focus on brewing science, as well as a
Ph.D. degree from TU Berlin. Nils is deeply interested in beer analysis,
preferring to track molecules that make beer taste either terribly good
or horribly stale. Currently, Nils is in charge of the VLB Research
Institute for Instrumental Beer and Beverage Analysis.
