In the typically obscure way of whiskey enthusiasts we were talking about light whiskey, a bad idea from the late 1960s. Someone produced a bottle of Four Roses labeled "light whiskey-a blend." I off-handedly opined that it probably was light whiskey blended with GNS (vodka).
It was not.
The reg says, "If 'light whisky' is mixed with less than 20 percent of straight whisky on a proof gallon basis, the mixture shall be designated 'blended light whisky' (light whisky—a blend)."
So I stood corrected, but it reminded me of something else that was pointed out to me recently. You can search Canadian liquor store shelves long and hard, and unless it has been imported from an American bottler you will not find a blended Canadian whisky. Up there they simply call it Canadian whisky.
The U.S. reg says "if such product is a mixture of whiskies, such mixture is 'blended Canadian whisky' (Canadian whisky--a blend)."
Canadian whisky is considered a blend even though it contains no GNS because it contains whiskeys of different types; i.e., corn whiskey, wheat whiskey, malt whiskey, rye whiskey, etc. It's all whiskey, by our definition and theirs, but of different types.
Likewise, blended light whiskey is a mixture of whiskeys, straight whiskey and light whiskey, no GNS. The "less that 20%" is because if it were more than 20% it would simply be "blended whiskey." Blended whiskey is straight whiskey (20% or more) mixed with whiskey (any kind) and/or neutral spirits.
Today, virtually all blends contain the minimum amount of straight whiskey and the rest is GNS, which is the cheapest combination possible under the rules.
Arguably, since it can't contain GNS and must contain some straight whiskey, blended light whiskey would be a more desirable product than either light whiskey or blended whiskey, at least on paper, but perhaps the difference wouldn't be great enough to win many converts.
I keep thinking that if sustained strong demand makes cheap straight 4-year-old bourbon a thing of the past, there might be room at that price point for products that bridge the gap. Stretching a little straight whiskey with light whiskey wouldn't be quite as cheap as a little more straight whiskey cut with GNS, but it would be close and a lot better tasting, at least in theory. It's just theory because nobody makes such a product.
And that's what makes this meditation so obscure.