Gouais Blanc is a little-planted white grape variety that in the past has been banned in France. It produces indeterminate, high-acid wines, but is indirectly responsible for some of the greatest wine in the world. Through natural crossings, it's the parent of Chardonnay, Aligoté, and Gamay in Burgundy/Beaujolais, as well as Riesling, Furmint, and Blaufränkisch. Without Gouais Blanc, wine as we know it wouldn't exist, nor would our understanding of DNA and grape genetics.