Abstracts

Please find below the abstracts from the current issue.
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Can tunnel pasteurisers harm the microflora?
Schädlichkeitspotential der Mikroflora von Tunnelpasteuren

During the 1980s, some publications discussed hygiene and process management. In the early 2000s, the Research Centre Weihenstephan for Brewing and Food Quality (FZW BLQ) began investigating why containers that had been untreated and were without pathological findings exhibited microbiological changes after pasteurisation. However, the results were inconclusive. The current project at Weihenstephan aims to answer three questions: 1. What grows in the pasteurisers and what influences growth? 2. Is it possible that process water enters the containers? 3. What risks are posed by microorganisms found in such a case?

Descriptors: Beverage contamination, test organisms, damage potential, process water
By Kunz, O., Gastl, M., Jacob, F., Zarnkow, M., Hutzler, M.
Source: BRAUWELT 18 2025 (165), 651-653

 

Beer brewing comes with a lesson
Bierbrauen mit Lerneffekt

The industrial evolution that has culminated in Industry 5.0 is redefining university education for industrial engineers. The main focus is on humanising industrial processes and paving the way for a harmonious interaction between humans and technology. The aim is to improve physical and cognitive abilities of the workforce, supporting inclusion, wellbeing and mindful interaction and ensuring that technological development is ethical and responsible.

Descriptors: Industry 5.0, Learning Factory (LEAF), Smart Factory, Erasmus program, LEONARDO project
By Schlechter, T.
Source: BRAUWELT 18 2025 (165), 658-662

 

Trusting sensory results
Sensorischen Ergebnissen trauen können

This contribution provides a survey of known errors in sensory tastings as well as potential pitfalls in the most common sensory tests.

Descriptors: Tasting sensory results, Tasting panel
By Voß, T.
Source: BRAUWELT 19 2025 (165), 707-711

 

Improving haze stability of alcohol-free beer
Verbesserung der Trübungsstabilität eines alkoholfreien Bieres

This paper examines the haze stability of a specific non-alcoholic beer. The beer in question is produced by blending a de-alcoholised Pilsner and a beer produced with arrested fermentation. Due to the different beer matrices of the two components and the fact that they are blended after separate filtration, the final product has poor haze stability. It was investigated whether use of PVPP could prolong shelf-life.

Descriptors: Alcohol-free beer, filtration, PVPP
By Huber, S., Krottenthaler, M.
Source: BRAUWELT 22 2025 (165), 806-810

 

The influence of protein content in barley and malt on beer quality (Part 2)

Annual monitoring shows that the protein content of malting barley has steadily declined over several years, as discussed in Part 1 of this article article series in BRAUWELT International, No. 4, 2025, pp. 206-209. The value-added chain will probably have to adjust to lower protein contents in malting cereals in the long term. Part 2 explains possible technological approaches for processing low protein contents.

Descriptors: Malt quality, protein content, winter malting barley, brewhouse settings, yeast management, supply chain
By Schneiderbanger, H., Gastl, M.
Source: BRAUWELT International 5 2025 (43), 1556-1558

 

Refining the craft of sour beers: a journey through fermentation, tartness and regional nuances

This review delves into the rich history, production, and diversity of beer, highlighting its enduring global popularity. Tracing its origins back to ancient grain fermentation, we explore the key ingredients of beer—barley and other cereals, water and hops. With Brazil emerging as the third-largest beer producer worldwide, the article emphasizes the country's pivotal role in global beer production and consumption. The focus then shifts to the intriguing world of sour beers, particularly renowned styles like Lambic, Flanders Red, Berliner Weisse, and Gose. These beers are notable for their use of non-Saccharomyces yeasts, which add complexity and distinct aromas. Special attention is given to the Catharina Sour, a Brazilian style that skillfully balances acidity with tropical fruit flavors, gaining increasing international recognition. Furthermore, the article examines modern brewing techniques, such as kettle souring, highlighting their efficiency in production while acknowledging potential trade-offs in flavor depth. The relentless pursuit of innovation within the sour beer industry—whether through traditional methods or the creative incorporation of new ingredients—underscores the importance of this review. Ultimately, this article sheds light on the evolving craft of sour beer production and its cultural and economic significance in today’s brewing landscape, complemented by a bibliometric review.

Descriptors: Bibliometric review, fermentation, flavour, fruit esters, microbiology, sour beers, "Catherine Sour"
By Felipe Reitenbach, A., Ferreira Ghesti, G., Sturion Lorenzi, A., Barros Maluly, H. D., Mattos dos Santos, P. C., Costa Barbosa, A., Humberto Petrycoski, H., Ichikawa Ezawa, L. E., Strong, G., Burin, V. M.
Source: European Food Research and Technology 10 2025 (251), 2959-2978, https://doi.org/10.1007/s00217-025-04810-1

 

A Fresh Perspective on Hop Composition: The Discovery of Starch in Hop Cones (Humulus lupulus)

Despite years of research, hop creep remains largely enigmatic to brewers and academics alike. This study adds a new dimension to this complex story with the discovery and quantification of starch within the bract of hop cones. Although glycosyl hydrolase enzymes from hops, are considered the main drivers of hop creep by breaking down complex sugars into fermentable ones, it was previously thought that these enzymes only acted on dextrins derived from malt during the mash. However, this study herein reveals that starch from the hop bract itself provides a previously unconsidered substrate, significantly impacting hop creep by contributing potential additional fermentable sugars. To confirm the presence of starch, hop products were stained with iodine. In addition, starch content and the monosaccharides involved in starch synthesis were quantified by high performance liquid chromatography. Starch was identified in hop bracts (mesophyll and stomatal guard cells) with visual confirmation using microscopy with the bracts stained with iodine. In addition, total starch (<0.5 to 1.6 g/100 g) and monosaccharide sugars (sucrose, glucose and fructose) were quantified in the bracts. The presence of starch provides unequivocal evidence that the enzymes responsible for hop creep are from the hop cone. This research emphasizes the potential additional role of starch in understanding the mechanisms underlying hop creep, contributing new additional insights to hops.

Descriptors: Beer, brewing, diurnal starch accumulation, hops, hop creep, Humulus lupulus
By Young, J., Fox, G.
Source: Journal of the ASBC 3 2025 (83), 282-287, https://doi.org/10.1080/03610470.2025.2455336