Toxin screening | Mould fungi are part of the mycoflora naturally present on malting barley. In recent years, the focus was on contamination with the fungus species Fusarium and Aspergillus whereas the relevance of contamination with sooty mould fungi has been recognised only a short while ago.

Hop Storage Index | As soon as hops have been picked and sufficiently dried, a race against time begins, or more precisely against oxidation, as the oxidation reactions reduce the quality of the hops. The Hop Storage Index (HSI) is used to assess this. How does it affect brewing and what factors influence it?

Hop industry | Argentinean hops are not in the spotlight when southern hemisphere hops are mentioned. This term usually is used for more famous hops from Australia, New Zealand, and sometimes, South Africa. But Argentina has a rich history in hop growing, although it is not well known by its products abroad.

Hop research | In December 2023, the latest Hop Special was published in the BrewingScience Newsletter, this time sponsored by BarthHaas. The scientific online-journal BrewingScience features peer-reviewed scientific papers with impact on the brewing industry. The brief article abstracts below provide a good initial overview of the content.

Summary | At the end of the year, our author Dagmar Hofnagel summarises the results of the 2023 spring barley harvest. The main topic remains quality and, as a result, the ability of buyers and users to compromise.

Flavour composition | Many brewers have tried to blend various hop varieties for imparting unique aromas to beers, mainly based on their experiences. If a mechanism for a hoppy aroma existed, such knowledge would help to formulate desirable blends of hops based on scientific evidence. In recent times, the mechanism of Sorachi Ace’s varietal aroma was discovered. Which hop varieties might thus be suitable for blending with Sorachi Ace hops? The following article summarises a part of the research results which have already been published in BrewingScience, 2022, issue 6, November/December.

Hop Storage Index | When evaluating hop quality, many use the Hop Storage Index (HSI) as a simple analysis to get an indication of how much the hop has been aged. The rule of thumb is: the higher the HSI, the poorer the hop variety was harvested, stored, and processed. Although HSI can be a useful tool, it is important to understand that the value should not be the sole indicator to understand the total hop quality.

Underestimated risk | Mould fungi are part of the natural microbial flora of malting cereals. In recent decades, intensive research focussed on the fungus genus Fusarium plant pathogen in this respect. However, the consequences of contamination with the so-called sooty mould fungi are hardly known in comparison.

Overview | The 2023 hop harvest has now officially come to an end. The Arbeitsgruppe Hopfenanalyse or AHA (Hop Analysis Working Group) has announced the mean alpha acid values determined in freshly harvested hops. The German AHA members comprise the in-house laboratories of the hop processing plants Hallertauer Hopfenveredelungsgesellschaft in Mainburg, Hopfenveredlung St. Johann GmbH, HVG in Mainburg as well as the laboratories at the Hop Research Center in Hüll, the Research Center Weihenstephan, the VLB Berlin and the Technical University in Berlin, in addition to Labor Veritas in Zurich, Switzerland and IHPS Žatec in the Czech Republic. These values form the basis for any amendments to supply contracts containing “alpha clauses” for aroma hops. In the table below, each hop variety is designated by type, either as an aroma hop (A) or a bitter hop (B), according to the IHGC (International Hop Growers’ Convention) classification system.

In addition to the data for freshly harvested hops for the current crop year, the alpha acid content of the hops harvested in recent years and the updated five and ten-year averages are provided below. These serve as the basis for new supply contracts with “alpha clauses” .

Alpha acid values for air-dried hops determined according to EBC method 7.4 for freshly harvested hops for the crop years 2014–2023 as well as the average content over the last five and ten years

Analysis methods | A beer is as good as its raw materials. Control using various analysis methods is required to ensure that malting barley and malt are of the highest quality. This article give an overview on how analysis developed from the first specifications of malt to up-to-date technical solutions.

From hops to beer | The choice of the hop variety is one of the key factors that determines the final aroma of beer. During beer production, hop volatile compounds are chemically and biologically transformed to form new compounds that are not significantly present in the hop cones. To understand the complexity of these modifications and their influences on the final beer aroma, 14 hop varieties were compared for their ability to apport aroma compounds to the beer.