I know these are all white wines from white grapes but what are the major differences between them?

They're different grapes! Pinot grigio is from a mutant variety (subspecies) of the pinot noir grape. It's actually kinda pinkish, but called grigio/gris/grey because it's halfway between pinot blanc (white) and pinot noir (black). Chardonnay is its own grape. And sauvignon blanc is a green grape from Burgundy (different from cabernet sauvignon).but overall, they're Vitis vinifera just different varieties.

In simple terms...chardonnay is buttery or oakey...approx...11% alcoholsauvignon blanc...similar to chardonnay, but, dryer...and approx 12.5% alcoholpinot grigio..is alittle sweet, and light.. 8% alcohol

Actually, Sauv Blanc originates from Bordeaux. Burgundy is Chardonnay. Traditionally, when you think Bordeau White, it's a Sauv Blanc grape. But, right now, some of the top inexpensive producers of Sauv Blanc are in New Zealand. The wines tend to be dry, crisp, and some can be quite citrusy. One of my summer wines this year will be a Marlborough Sauv Blanc. (Kim Crawford 2006)Chardonnay is, as I said, a major Burgundy grape. It is used to make Champagne and obviously, is used as a still wine. The flavours of Chardonnay vary greatly, but many are grassy, oaky, and sometimes even vanilla-y. It can be one of the heavier white wines and can go with a wide array of foods. A icely oaked but fresh Chardonnay was my summer wine two years ago. (Maryhill Reserve Chardonnay)Pinot Grigio/Pinot Gris tends to be light and crisp. The grapes can be any colour from whitish green to bluish to nearly black. It can be fruity, but is not traditionally sweet (in the US anyway). German and French Pinot Gris may be slightly sweeter - but not like a sweet Viognier or Cheap Gerwurz sweet. One of my first summer wines was Duck Pond Pinot Gris. Goes down easy and costs very little. Hope this helps! : )

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