“Gushing is the vigorous overfoaming of carbonated beverages when the bottle is opened.”
Don’t you just hate it when that happens? But (other than too much priming sugar as in the example above) why does it happen, and what can be done about it? Answers can be found in a 2014 paper in the Journal of the American Society of Brewing Chemists (vol:72 issue:1 pp:12-21) entitled: ‘A Curative Method for Primary Gushing of Beer and Carbonated Beverages: Characterization and Application of Antifoam Based on Hop Oils.’ It’s authored by Zahra Shokribousjein (1), KULeuven, Department of Microbial and Molecular Systems (M2S), and Leuven Food Science and Nutrition Research Centre (LFoRCe-MaltBeerSci), Heverlee, Belgium; An Philippaerts, KULeuven, Centre for Surface Chemistry and Catalysis, Heverlee, Belgium; David Riveros, KULeuven, M2S, and LFoRCe-MaltBeerSci; Jean Titze, National University of Ireland, University College of Cork, School of Food and Nutritional Sciences, College Road, Cork, Ireland; Yannick Ford, Barth Innovations Ltd., Hop Pocket Lane, Paddock Wood, Kent, TN12 6DQ, United Kingdom; Sylvie M. Deckers, Mohammadreza Khalesi, Jan A. Delcour, Kurt Gebruers, and Hubert Verachtert, KULeuven, M2S, and LFoRCe-MaltBeerSci; Vladimir Ilberg, Research Center Weihenstephan for Brewing and Food Quality, Technical University of Munich, Alte Akademie 3, 85354 Freising-Weihenstephan, Germany; Guy Derdelinckx, KULeuven, M2S, and LFoRCe-MaltBeerSci; and Bert Sels, KULeuven, Centre for Surface Chemistry and Catalysis, Heverlee, Belgium.
“Primary gushing in beer is mostly caused by a group of proteins called hydrophobins secreted by filamentous fungi, which contaminate CO(2) gaseous molecules during carbonation and form nanobubbles. The influence of hop oil antifoam on primary gushing showed a complete suppressing effect in sparkling water, a decreasing effect in wort, and no influence on gushing-positive beers…. Because hop antifoam molecules are hydrophobic, they interact with hydrophobins and prevent interaction with CO(2) and, consequently, inhibit the possibilities of development of the explosive nanobubble structure.”