Although Hawaii’s generally tropical climate shares little with the great wine-making areas of the world, grape growing is possible in Hawaii at elevations above 1500 feet. Hawaii’s main variety is Symphony, a white wine grape created at UC Davis by crossing Muscat of Alexandria with Grenache Gris.
Hawaii also makes a variety of fun and refreshing fruit-blended wines. The resulting, fruity and off-dry to sweet, is ideally suited for Hawaii’s beaches and tropical climate. Hawaii has three wineries, one on Maui, one on Oahu and on the Hawaii. Tedeschi Vineyards/Maui's Winery at Ulupalakua Ranch has started limited production of an island-grown Syrah.
Tours typically last from 30 to 60 minutes per tour and they are well worth your time to check out the different ones. Each one has their own flavors, beauty, and charm to experience.
What is even more awesome is that most wineries offer free samples of their wines when you go through a tour as well. Some do more formal tasting events as well. The tours are extremely interesting and fun to do too. They aren't just there to sample the wine that you're looking forward to but are actually very informative and you get to meet a lot of like-minded people usually that are also doing the tour. It's always nice to a fellow wine lover! - Be sure to call ahead if you are planning on doing a tour at one of the wineries or vineyards though to check on availability since many of them get very busy during season.