Lake Michigan Shore is an American Viticultural Area (AVA) in south-western Michigan, within the Great Lakes region of the United States. The AVA is by far the most important in the state: more than 90 percent of Michigan's vineyards can be found within Lake Michigan Shore and more than half of the state's wine output comes from here. Chardonnay, Riesling and Pinot Noir are grown in the area's vineyards, along with hybrid varieties such as Chambourcin and Ravat Vignoles.
The AVA covers nearly 1.3 million acres (526,000ha) of low, rolling hills on the south-eastern edge of Lake Michigan, extending inland for around 45 miles (70km). The Kalamazoo River makes up the northern boundary of the wine zone, where the sub-AVA of Fennville can be found. The southern edge of the Lake Michigan Shore AVA runs along the state border with Indiana.
Lake Michigan Shore is subject to the lake effect, an oft-mentioned phenomenon in the Great Lakes region. Lake Michigan acts as a temperature moderator throughout the year, making the area suitable for viticulture despite its northerly position. In spring, winds coming off the chilled lake delay bud burst until after the greatest frost risks have passed. In summer, the lake warms up and during fall, the growing season is extended by warm air from the lake. In winter, heavy snow buries the vines and helps to protect them against ground freezes. The climate of Lake Michigan Shore is such that the growing season here is often several weeks longer than in Michigan's more-northern AVAs of Leelanau Peninsula and Old Mission Peninsula.
The terrain of Lake Michigan Shore is largely the result of glacial movement – the same glacier that formed the Great Lakes in the last Ice Age. Sandy slopes and hills made up of glacial moraine provide a free-draining, deep base for the vines, allowing for deep, strong root systems, and good air drainage on these slopes helps to lessen the risk of frost damage.
The first vines were planted in Lake Michigan Shore in the 1860s, and by the turn of the century there was a large swathe of land in the region under vine. Prohibition had a minimal impact on the region's growers, who turned to grape-juice production in the 1920s to tide them over until the repeal of the law in 1933. In the 1930s, there was a further surge in vinous activity, and eventually the region was delimited as Michigan's second AVA in 1983, following Fennville.
Lake Michigan Shore is traditionally a fruit-production area, and only a small portion of the grape vines in the AVA are intended for viticulture. The majority of the acreage is planted to varieties such as Concord and Niagara, with grapes used for table juice and jellies rather than wine. However, the wine-grape output is sufficient to supply about 50 wineries, the finest of which line Lake Michigan's eastern shores.
