Sentence:  The third category of wines is highly unattractive as these may only be sold as generic wines (white, red or rosé), without reference to any geographical location. Only surplus <WSD>plonk</WSD> and cooking wine would aspire to fall in this segment, which can be blended with any other wine - to any extent. 
Meaning of the word marked with <WSD> tags:  (wine)  Cheap or inferior everyday wine.