First, it was the brewers who looked beyond the confines of their breweries into the vineyards and cellars of the wine producers – inspired perhaps by the iconic Midas Touch, a beer produced in 1999 by the American Dogfish Head brewery based on a model from ancient times using barley, grapes, and honey. Since the turn of the millennium, the brewing scene has been exploring the overlap between beer and wine, developing recipes and technologies, and using must, grapes, or pomace.
These are added to the beer at various stages of fermentation, lagering, or aging – sometimes even in wine barrels. The art of producing these so-called beer-wine hybrids has been mastered by Italian breweries. They have elevated Italian Grape Ale (IGA) to a national (and international) beer style first included in the BJCP Guidelines in 2015.
One of the greatest challenges here is to produce an IGA from a very strongly hopped base beer – skillfully ensuring that the hop and grape aromas complement each other, so that sweetness, acidity, and bitterness are in harmony. A particularly successful example of this was the West Coast IGA released by Stone Brewing Berlin and Birrificio Lambrate in 2019: Must from Italian Malvasia Bianca grapes united in a beer with American Citra, Mosaic and Enigma hops to produce a perfect fruity bouquet with distinctly winey overtones, refreshing acidity, and highly polished bitterness.
Meanwhile, inspiration is flowing in the other direction, too. Winemakers are broadening their horizons and borrowing some of the brewers’ techniques: Above all, that of dry hopping, as in A Glimmer of Hops from Weingut Weninger in Austria’s Burgenland region, a directly pressed Blaufränkisch dry-hopped with wild hops during fermentation in amphora. Other interesting examples are Hurra Gehopfter, a dry-hopped Riesling made by Hurra Craftweine, a wine and sparkling wine producer based in Geisenheim, Hop and Grape, a dry-hopped Sauvignon Blanc by Daniel Mattern from Mettenheim, and the hopped Chardonnay by Nachmelené from the Czech Republic.
These hop-wine hybrids are still a recent phenomenon that – similarly to hopped cider or mead – is opening up the market for exciting new alcoholic beverages. In sensory and technical terms, the challenges here are similar to those with West Coast IGA from Stone/Lambrate. A well-balanced and polished flavor can only be achieved through painstaking development work in the brewhouse or wine cellar. Too little is known about the interplay of hops and wine.
Matching the varieties in sensory terms is one thing. But what is even less foreseeable is the biotransformation. Depending on the type of yeast used, fermentation may alter or strengthen the grape and hop flavors – both in the beer and in the wine. The release of fruity thiols through beta-lyase activity plays an important part here, as does the release of glycosidically bound floral and citrusy terpene alcohols or the presence of reductive reactions such as the conversion of geraniol into beta-citronellol.
A paper by Svedlund, Evering et al. published in Applied Microbiology and Biotechnology provides an overview of the current science on the subject of biotransformation reactions in beverage production. In general, greater understanding of biotransformation may contribute to greater consistency of flavor being achieved in beverage production and, beyond that, to greater sustainability in the production process. The BarthHaas Brewing Solutions Team has focused on this subject for a long time and will be pleased to provide wine producers with advice. Hops and dry hopping revolutionized the world of beer. We’ll be glad to help them bring lasting change to the worlds of wine, cider, and mead, too.
