ADrunkenBotanist

Viticulture PhD student here. MA is pretty commonly used where I am. Mostly on red grapes -- probably a color attractant for birds, because they're the only grapes the birds are voraciously after. The vineyard I'm working in used MA mostly on Pinot Gris and Pinot Noir, where they can lose up to half their yield to swallows sparrows. Crazy stuff. We'd like to work on detecting MA in the wine from their grapes. As is, I bought a bottle of the Pinot Noir rosé from 2014 (the first year they sprayed MA), and it seems fine to me.

edit: birds are bad juju all around for grapes

Wine grapes were bred for things like aromas, flavors, colors, acidity, sugars. Wine ABV is ~1/2 of the total soluble sugar content (brix) of the grape, making it quite a bit higher than table grapes. If you go to wineries, though, you can find products like Vidal, Cabernet Franc, and Riesling grape jellies, so that's kind of cool.

TBH, wine grapes are also really tasty, but their seeds are small and obnoxious. So, yeah, that's why Thompson seedless are so popular for raisins and fresh eating.

Grapes like Concord are like the all-purpose variety. They are used for juice, jam, eating, and wine.

Ultimately, price is reflected in the difficulty of cultivation (labor requirements for high quality production), as well as yield capabilities and mechanization. Being that wine grapes are into the $1000's per ton, it's not something you'd necessarily want to be fronting costs for at the grocery store.

yeah, GC-MS. Super common technique for grape aroma compound analysis.

Sparrows, robins, starlings eat them (good catch, thanks). Swallows peck them when swooping. Yield gets lost to both eating and sour rot from beak punctures.