A new paper published in Climate of the Past reconstructs temperatures in Switzerland from 1444 to 2011 on the basis of grape harvest dates and finds temperatures were about the same as today at the beginning of the record around 1450 AD, and that temperatures of today have been matched or exceeded several times in the past. In addition, the paper finds European temperatures during the summer of 1540 were 4.7 °C to 6.8 °C higher than those of 2003, causing more extreme heat & drought than the “record breaking” heat & drought of 2003.
More details at the Hockey Schtick.
Grapes are very sensitive to the climate, requiring a number of degree days to mature and generate the sugars need to make good wine. Short season, bad wine. Long season, better wine. I can see the Maunder Minimum in the graphic, but having a harder time seeing the Dalton Minimum.