LILLE 2024

Proteins in raw materials play an important role in both the malting and the brewing processes, as players in raw material biotransformation, or as contributors to foam, haze or even as a nitrogen source for the yeast.
Nonetheless, a comparable total protein content of barley can lead to various malt qualities and different proteolysis level. Indeed, barley proteins are poorly studied, and their detailed composition is not well-known.
In the context of climate change, reduced inputs (including fertilisers) and the need for more sustainable raw materials, the aim of the project was to identify the barley proteins that play a major role in brewing quality, in order to provide breeders with indicators to monitor in the early stages of varietal selection.
The collaborative project “PROsIT” (PROteins of InteresT) proposed to establish the qualitative profile of the various barley proteins and to identify the possible relationship with malt quality (e.g. enzymatic and technological parameters).
The influence of barley variety and crop conditions (fertilisation schedule, location and year of cultivation) on the qualitative profile of proteins was also studied and discussed.

Hop leaves are a potentially valuable source of bioactive compounds which could provide value to the food, beverage or cosmetics industries. This study evaluated hop leaves and corresponding cones for their polyphenol composition (LC-ESI-qTOF-MS/MS and HPLC-DAD) and associated antioxidant activities (DPPH, FRAP and ORAC). Leaf samples were sourced for 3 varieties grown in Yakima over 2 harvest years and at different stages of development post-flowering. Chlorogenic acids and flavonol glycosides were the most abundant polyphenols in leaf extracts, with procyanidins, prenylflavonoids and bitter resins present at lower levels. Glycosides of quercetin and kaempferol were quantitatively the most abundant polyphenols, and consistent varietal differences were observed across crop years. Hop leaves at all stages of development were shown to have lower concentrations of polyphenols / antioxidant activity and substantially lower proanthcyanidins and prenylflavonoids than their respective cones. Results show the contributions of identified compounds in hop leaves to the overall antioxidant activity of extracts, which depended on variety, crop year and stage of development.

Hop creep continues to thwart breweries with consequences that threaten beer quality and safety. This work groups hops based on selected factors – type, growing region, variety, and concentration – with the aim to provide general guidelines about which produces the most creep. The results seek to inform and significantly enhance brewery operations, enabling practical solutions for implementation across dry hop processes, wort compositions, and recipe designs. For this study, over 450 fermentations were performed with 5 product types, 6 growing regions, 25 varieties, and 1g or 2g quantities (2lb/bbl = .9kg per 1.17HL and 4lb/bbl = 1.81 kg/1.17HL, respectively). These experiments found several significant differences indicating meaningful causal effect of tested variables on the extent of hop creep experienced. Some of the most common varieties, product types, and growing regions are all similar in their hop creep capacity, allowing for high consistency and therefore relative predictability in secondary fermentations.

In conventional hop cultivation pesticides are are commonly used to control diseases.
However, due to ecological concerns and decreasing efficacy of pesticides, it is expected that in the future not only green cones will be harvested, but also those with visible disease infestation.
This study investigates the effects of a pronounced infestation with peronospora, powdery mildew, hop aphids, and red spider mites on hop and beer quality characteristics, using healthy green hops for comparison.
The analysis revealed no significant differences between green and brown hops in terms of bitter compounds, aroma components and polyphenols. Brewing tests did not reveal any analytical differences between beers brewed with green and brown hops, analogous to the results for hops. Only in rare cases, particularly in late or dry-hopped beers a moderate preference for green hops resulted. Contrary to brewers´ general expectations, no significant defects were observed in beers brewed with heavily infested hops.