When I lived in St. Louis, I tried various red wines from the nearby Augusta wine region. I've also tried many NY wines from the Fingers Lakes region and Canadian wines from Ontario. While I've enjoyed the ports from Missouri and the icewines from Ontario, I dislike the red wines of these regions.
I cannot believe that the marked differences between local and non-local wines and the marked similarities between all "local" wines can all be chalked up to differences in soil, climate, growing season, pruning techniques and other features of terroir. My current hypothesis is this: Unlike the red wines of larger, more established or more prestigious winemakers, local red wines do not go through a process of malolactic fermentation.
Primary fermentation occurs when yeast is added to grape juice and converts grape sugar to alcohol. Other byproducts of this process include carbon dioxide, malic acid and heat. Secondary (or malolactic) fermentation is a process that converts the more bitter, tart or metallic-tasting malic acid into the softer-tasting lactic acid. This process is accomplished with the help of lactic acid-eating bacteria such as Oenococcus oeni, Pediococcus and various species of Lactobacillus.
All good red wines undergo malolactic fermentation. Traditionally, Old World white wines did not undergo this same process. In the 1970s California winemakers established a new style and standard for Chardonnay by combining malolactic fermentation of their white wines with oak aging. It is the secondary fermentation process that gives California Chardonnays their distinctive "buttery" flavor. The buttery sensation arises from the softer, slightly oily texture and flavor of the lactic acid.
Because of malolactic fermentation, California Chardonnays can be drunk more easily as aperitifs. Many Old World Chardonnays are not intended to be drunk by themselves and often need to be tamed by a full meal. Because the California style fits better with New World wine drinking habits, it has significantly changed the oenological landscape. (Notice that in every American wine magazine advertisement, the partakers are standing at a party rather than sitting before a meal.)
With white wines, then, there are two styles: with or without malolactic fermentation. With red wines, however, there is only one: with. My best guess as to why local wines possess a chemical whang not found in non-local wines is that they do not generally undergo the secondary process of fermentation.
I recently ran my hypothesis by a senior wine buyer at Prime Wines, and she completely dismissed my hypothesis. I'm not giving up on it yet, however, because I don't know of any other explanation for the distinctive aroma and flavor profile of local wines. If any of you have hypotheses of your own, please share them with me.