Indiana is a state in the American Midwest, between Michigan to the north and Kentucky to the south. The state covers 36,500 square miles (95,000 sq km) of fertile plains and shallow valleys, which are well suited to the production of fruit and cereals. The vineyards that produce the majority of Indiana's wine are largely planted with Franco–American hybrid varieties, with increasing focus on those that are less susceptible to the challenges of a warm, humid climate. Chambourcin, Marechal Foch, Catawba and Vidal Blanc are common here.
In the early 19th Century, Indiana was home to some of the first large-scale vineyards in the United States, planted with early hybrid grape varieties. However, as in so many US states, vine disease, war and Prohibition decimated Indiana's flourishing wine industry and signs of significant recovery were not seen until the American wine renaissance of the 1970s.
The state is now home to around 30 wineries, up from fewer than 10 when the Indiana Wine Grape Council was established in 1989. This increase has been mirrored by a tripling of the total area under vine in Indiana, which now stands at more than 500 acres (200ha). In 1987, the state was granted its first American Viticultural Area (AVA) – the colossal Ohio River Valley, which it shares with Kentucky, Ohio and West Virginia. This has since been joined by the smaller AVA of Indiana Uplands, which was granted in 2013, becoming the first AVA entirely within the state.
Indiana is classified as having a humid continental climate, with cool winters and warm, wet summers. The southern end of the state receives significantly more rainfall than the north, because it penetrates into the humid subtropical zone whose boundary is effectively marked by the convergence of the Ohio and Mississippi rivers. It is here that the modern Indiana wine industry is developing, particularly in the hills in the south-east. That said, the humidity of the climate poses particular problems, and the state's viticulture students and professionals continue to search for hybrid varieties resistant to the fungal organisms responsible for diseases like mildew and black rot.