Depends on what you mean by "real". If the end purpose is maintain consistency of taste, of course that stuff is blended, grape quality and taste varying year by year.
As for the alcohol, I hadn't thought about that. Just from the taste variances in vodka alone, I guess that would make a big difference.
Why use 190proof corn alcohol (what Heinz uses to make their white vinegar) when there are probably lakes (to use a EU wine policy term) of really bad and undrinkable wine to fractionally distill once, and use as the fortification boost/base?
I meant whiskey, tequila, vodkas.
It is mostly made from corn alcohol, not the appropriate source. Flavoring is added at the bottling vat.
This includes some very expensive famous brands.