Author(s):
Tony B Shaw, Professor* - Brock University
Abstract:
Tony B. Shaw
Department of Geography
and
Cool Climate Oenology and Viticulture Institute
Brock University
St. Catharines, Ontario
L2S 3A1
Canada
E-mail: tshaw@brocku.ca
905-688-5550, Ext.3866
The wine regions of Ontario's are often considered to be at the climatic margins of commercial viticulture due to their cold winters and short cool growing season. On one hand, these regions are likely to benefit from a warmer climate that could extend their growing seasons and moderate cold winter temperatures. On the other, the production of internationally renowned ice wines could be jeopardized by unpredictably warmer spells during the first half of winter.
This paper examines the trends in winter temperatures over the last forty years for the two principal wine regions in Ontario that are also the major producers of Ice Wine in a wide range of styles. The study analyzes the occurrences of temperatures = -8o C in the months of December, January and February in which the frozen grapes are normally picked. Even though the grapes may be frozen on several occasions at higher minimum temperatures, the temperature at harvest must fall to -8oC in order to be certified as ice wine according to the Vintners Quality Alliance (VQA) standards. The ideal conditions should include dry and moderately cold conditions over a two week period with partial freezing followed by a real freeze with daytime temperatures between -9o C and -11o C in the months of December and January.
