Characterization of Italian Grape Ale beers obtained with different additions of Malvasia di Candia Aromatica must and marcs

Abstract

In 2015, a new style of fruit beer, called Italian Grape Ale (IGA), was introduced by the Beer Judge Certification Program. The style of this beer is defined as a union between beer (wort or final beer) and grape or grape must (from red or white cultivar). This study aimed to characterize the chemical composition and sensorial properties of IGA beers obtained by adding grape juice or marc. To this aim, different amounts of grape juice or marcs (10 % and 20 %) from cv. Malvasia di Candia Aromatica (MCA) were blended with Golden Ale wort before primary fermentation. The addition of MCA grape marc and juice resulted in a significant increase in total fermentable sugar concentration, organic acids, and higher titratable acidity, both in the wort and in the final beer. Furthermore, the CIELab colour space parameters were strongly influenced by MCA, with the additions of marc leading to the most pronounced colour changes in beer, producing a dark yellow hue. Regarding the volatile profile of IGA beers, the MCA additions modulated the profile of IGA beers with key markers that consisted mainly of terpenes (both free and glycosylated forms), higher alcohols and esters. These compounds, as confirmed by sensory analysis, enhanced the aroma of beer samples with floral and fruit notes, making them easily distinguishable from IGA traditional beers. These findings are among the first data available on the effect of white aromatic grape juice and marc in brewing, both from a chemical and sensory point of view.