Designation for a relatively long-lasting climatic phenomenon from 1450 to 1850, which occurred worldwide with regional and temporal emphases in Europe, North America, Russia and China. Prior to this, there had been a pronounced temperature peak in the period from 900 to 1350, mainly in Europe, which was called the Medieval Warm Period. At that time, the wine growing border lay much further north on the southern Baltic Sea coast. From 1450 the climate began to deteriorate again. Particularly cold periods extended from 1570 to 1630 and from 1675 to 1715, which were associated with a worldwide expansion of the glaciers. Around the year 1700, the largest expansion of ice occurred, after which the glaciers slowly retreated again. By the way, this retreat still continues today, many glaciers in the Alps have already completely melted.
There were always extremely cold, frosty winters and rainy, very rainy summers. The average temperatures were one to one and a half degrees Celsius lower than today. Agricultural failures were the result and the resulting famines threatened the population. This led to several waves of emigration, especially to North America. In the 15th century the Baltic Sea froze completely at least twice. In the winter of 1780 it was possible to cross the port of New York on the ice. On the Great Lakes in North America the ice sometimes remained until June. The year 1816 was particularly extreme in the northeast of America and in the west and south of Europe. It went down in history as the "year without a summer" and was therefore popularly known in Germany as "Achtzehunderunderfroren" (Eighteen hundred and fifty percent frozen).
Viticulture in Europe was also severely affected by the climate change and there were many failed harvests with bad and over-acidic vintages, but these were repeatedly interrupted by good and outstanding years with even some century wines. A particularly acidic vintage was produced in Vienna is known as a ripper. See also under climate, climate change and winegrowing worthiness.