“…On the other hand, dolia (and qvevri) were made in specialised workshops, using specific clays and firing procedures aimed at obtaining ideal air permeability for wine fermentation, and hence flor formation. In addition, many Roman high-quality wines were made from raisined grapes, which produced musts with high sugar levels ideal for flor building (Van Limbergen 2017, 2020; Dodd 2020: 59–64). These surface yeasts produce several chemical compounds, including acetaldehyde and acetoin, but most notably sotolon, which is responsible for the slightly spicy taste of flor wines (and indeed many qvevri wines), and imparts aromas of toasted bread, apples, roasted walnuts and curry (Robinson 2006).…”