Interview with Prof. Freddy Delvaux, Brewing and Malting Laboratory, KU Leuven

INTERVIEWS

“Beer is an important product, it would be naive not to study it.” It’s rather peculiar, wandering about in a lab and suddenly being confronted with a wall of beer crates, a “Primus” tray or a back fitting full of beer glasses. Everything here is obviously to do with beer, but that doesn’t mean that the minds are fuddled. On the contrary, as illustrated by Professor Freddy Delvaux and graduate student Kevin Verstrepen in rather infectious manner.

“Leuven is a beer city. But this lab has a fairly recent history. The tradition of brewery research was interrupted for a while after the splitting of the university. Professor Jean de Clerck, an undisputed world authority, moved with his lab to Louvain-la-Neuve, and there was no real successor. Around 1990, when Professor Goedseels was director of studies here, the link to history was reforged.” Professor Delvaux was working in those days at Stella/Interbrew, but allowed himself to be persuaded to ally his technological expertise with scientific research at the K.U. Leuven. “The only problem was that was literally nothing there, no apparatus, no staff, no money. Fortunately, however, there were some good contacts with a number of breweries that drummed up the starting capital via consultancy to buy the basic equipment for the lab. Over the past ten years we have managed, step by step, to put K.U. Leuven back on top of beer research.” “The close connection with the industry is, of course, fairly typical for all engineering establishments but, in our case, it is very explicit. In recent years we have had to very consciously do what had to be done to counterbalance the industrial “problem solving”, via an accent on fundamental research. But, even there, the link with the industry is never really far away. It’s inevitable. We have contacts – and contracts – with some thirty breweries, and it would make absolutely no sense to just throw them overboard and aim solely at research. Naturally, the contacts also entail risks. First, we get the scientific bodies and funds telling us to go and look for our research money from the industry: a product such as beer is less ‘researchogenic’ than, say, heart disease or genetics. And, secondly, the direction of our work towards the industry means that our best researchers run the ‘risk’ of being bought away. Quite a lot of our graduates don’t reach the finishing line, simply because they are offered attractive jobs in one or another allied brewery. We are now trying to contain that partially by setting up our own spin-off, but we still have to settle a few matters first.”
“A lot is happening here with relatively limited resources. There are about fifteen staff, two part-time assistants, and then mainly graduate students and a number of project engineers for the technical side of things. The teaching given here is intended for the students of our faculty and for the industrial world. Each year we give them an intensive English-language lessons package a professional tasting course. Unfortunately, because of the high material requirements – to learn to brew, you need a brewery, … – besides the bio-engineering students, we can accept only a few external students per year. Given the growing number of final-year students each year wishing to do their degree project in our laboratory, the “Master in Malting and Brewing” programme comes under pressure.”

Wide-ranging research

“Our research is quite diverse. The first branch or our research is concentrated on basic materials. In concrete terms: we are looking for better malts. For anyone who doesn’t know: malt is a germinated and “oasted” barley. And for anyone who doesn’t know what oasting is: it’s a kind of kiln-drying process. The taste of the beer naturally depends very much on your basic ingredients. But they in turn can influence the storage life of the product. Brewers have understandable reasons for wanting to add as little as possible to their beers. So it all comes down to finding a winning combination of taste and storage life that also gives good flocculation, the right cloudiness and so forth, using ingredients that are as natural as possible. The use of alternative ingredients and the application of secondary fermentation in the bottle can probably also open new perspectives here.” “The second area of research concerns fermentation, the heart of the brewing process. Wort, the malt infusion, is brought together with yeast cells that break down the sugars in the wort. This produces carbon dioxide, ethanol and a series of flavourings. Our research into fermentation is mainly concentrated on the aeration phase. That’s strange really: oxygen is pretty much taboo in brewing, because it accelerates oxidation and spoils the taste. Air is, however, necessary at the beginning of the fermentation process. This is usually a case of pumping oxygen into the wort, but there are important reasons for oxygenating at yeast-cell level instead. This is known as yeast preoxygenation. The second form of fermentation research is actually our showpiece. If it works, it will start a revolution in the brewing process. For centuries, brewing has been done in batch form: you do something in the first vat and, once the process is completed, you run it all on to the second vat, and so on. Of course, this method works well enough, but it forces you to set up very large installations, and it’s difficult to guarantee a constant quality. Through continuous fermentation it should be possible to tackle the brewing process as a single whole, in a sort of moving belt. That’s more compact, and much easier to control. It’s been proven to be possible at lab scale, but the step up to industrial-scale production is still rather large.”
“Our third area of research is directed towards understanding and, more particularly, controlling flocculation – the clustering of yeast cells at the end of the fermentation process. This has consequences for many properties of the beer. We are also conducting intensive research into the formation of smells and flavours by the yeast. And how do you control the many aspects of the fermentation process? This is very international and interdisciplinary research in which we co-operate, for instance, with professors Thevelein and Winderickx from the laboratory for molecular cell biology, and with the universities of Oxford, Stellenbosch and Otago.”
“Our last-mentioned field of research is actually a carry-over from earlier research. A few decades ago, some beers still contained rather a lot of nitrosamines, toxic substances formed during the oasting and kiln-drying of the malt – not that it made you seriously ill, but it was undesirable. That’s hardly still the case these days, but the apparatus and expertise is now applied in certain tests on other food products. Incidentally: beer is at least as healthy as red wine, if you drink in moderation, that is. It has a demonstrably positive effect on the heart and the blood vessels.”

Students learn beer-drinking

“Our lab is a little unusual with, for example, its close connection with the industry, but also, of course, the object of our research. The outside world is probably having a good laugh at our expense, but that doesn’t worry us. Beer is an important product, and it would be naive not to study it. The apparatus to detect and quantify the many hundreds of components and volatile substances is not only very expensive, but also demands a high degree of technical expertise. That’s why our graduates have no problems finding work in the sector.”
“A ‘nice beer’ is clearly a question of taste. Despite the usefulness of all the physical and chemical analyses, the flavour – taste and smell – of our numerous beer varieties is still the main criterion. We pay close attention to the sensory side of beer-drinking, tasting if you will. That is, of course, partially subjective, but many aspects can still be quantified and learnt. We always need ‘connoisseurs’ and fine palates. We even train them. Twice a week we hold tasting sessions – double blind, in dark glasses, without speaking to each other, in order to be able to judge as objectively as possible. To be admitted, our students must first learn how to taste. The course lasts approximately one year, during which they train to taste ‘chemically guided’. If a brewer asks us to judge his product, we, or our tasters, must be able to tell him something about the taste, but also about the technical aspects behind the taste. Our panels must therefore be well trained. And is that always pleasant? I should say so. Commitment to this work and the projects is especially high in this lab. Could this be perhaps because we combine the pleasant and the useful?”

Source: Campuskrant KU Leuven, 20 June 2002. Author: Ludo Meyvis

 

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