The first Icewine (Eiswein) is believed to have been made in Germany in the late 1700s when freezing weather struck before the grape crop could be harvested. The winemaker persisted, harvesting and pressing the frozen grapes and fermenting the juice to a sweet wine.
The first Icewine to appear on the Canadian front was a Riesling, made in British Columbia by Walter Hainle and his son Tilman in 1973. Tilman Hainle and and his wife Sandra continued experimenting with Icewines at their Hainle Vineyards in the Okanagan, ultimately producing their first commercial release in 1978. In 1991, other Okanagan winemakers joined in, capitalizing on the early onset of cold temperatures that year and plenty of frozen grapes on the vine.
The story that lead to Canada been known around the world for its icewine is far more in depth and took the efforts of many to achieve. Perhaps the most important factors is Canada's unique climate.