Technical Session 06: Quality Considerations Session
Christina Schönberger, Barth-Haas Group, Barth Innovations, Joh. Barth und Sohn
Co-author(s): Sylvie Deckers, KU Leuven, Department M2S,
Malt & Beer Sciences and LFoRCe, Belgium; Jean Titze, National
University of Ireland, University College Cork, School of Food and
Nutritional Sciences, Ireland; Vladimir Ilberg, Hochschule
Weihenstephan-Triesdorf, Fakultät Gartenbau und Lebensmitteltechnologie,
Germany; Guy Derdelinckx, KU Leuven, Department M2S, Malt & Beer Sciences and LFoRCe, Belgium
ABSTRACT: During the last decade a lot of research was
performed on an undesirable and unexplainable phenomenon called gushing,
which is characterized by a spontaneous and wild liquid expulsion of
carbonated beverages that occurs immediately after opening the bottle
without any shaking. Gushing is a tremendous problem for breweries as it
is unpredictable and can cause severe delivery and image problems. This
work reviews all relevant findings in brewing science throughout the
last 20 years and explains the gushing phenomenon based on the facts
that are known today. While secondary gushing is due to technical and
technological problems, primary gushing is related to the use of raw
materials contaminated by a filamentous fungi, a producer of a human
safe and amphiphilic protein called hydrophobin. By forming a solid
condensed pellicle (i.e., crystalline layer) around gaseous CO2
Class II hydrophobins are responsible for the presence of gaseous
nanobubbles insulated from the liquid and pressurized at 4 bars in a
bottled beverage. These nanobubbles explode upon opening due to the drop
in pressure. This explosion provides the energy required for
nucleation, which results in the fast escape of dissolved CO2 and gushing. Knowing the interaction of hydrophobins and CO2,
possible solutions for gushing have to be looked for in any material
that may interfere with the formation of stabilized nanobubbles. In this
regard various hop components seem to be of interest. As gushing is a
worldwide problem, it seems important to make a review of this
phenomenon and which possible hop characteristics, as a typical
ingredient in beer, could offer a solution.
Christina
Schönberger studied brewing and beverage technology at the Technische
Universität München-Weihenstephan, Germany (1995–1999), graduating as an
engineer in 1999. After working as a brewing intern in 2000 at Suntory,
Japan, she pursued doctoral thesis work at the Chair of Brewing
Technology I on “Sensory and Analytical Characterisation of Non-volatile
Taste Compounds in Bottom Fermented Beers,” with which she graduated
summa cum laude in December 2003. For her doctoral thesis she received
the Dr. Nienaber Award in 2005. After working for the German Brewers
Association for one year as a consultant for technical and governmental
issues, she joined the Barth Haas Group in 2005 as manager of technical
sales. Within this role she is also responsible for the guidance of
research projects and authors hop related professional articles.
Christina currently holds the role of International Director on the ASBC
Board of Directors.
VIEW PRESENTATION 21
