It’s “variety.” It’s almost never “varietal.” Stop using “varietal” unless you’re absolute certain you know what you're doing, and even then consider reconsidering.
Evidence on this blog to the contrary, there aren’t all that many things in the wine world that drive me to tooth-grinding agony. I argue, yes, but I do so from a position of peace and goodwill towards all. It’s the Summer of Love, every day, on oenoLogic.
(Um, what’s that? I’m full of what?)
Anyway, the errant conflation of “variety” and “varietal” is the burr in my craw, the stick in my saddle, the hazelnut and pumpkin syrup in my charred coffee. Herein, a brief tutorial, the better to save the oenologician from the grammatical chafing caused by burr, stick, and venti latte. Pay attention, now.
(No, really. Brief. What’s that? I’m even more full of what?)
Variety – This is the word you want when you’re referring to a grape. Pinot noir is a grape variety, which you may shorten to variety. It is not interchangeable with the word “varietal.” And if you think it might be, start swapping the words in situations not related to grapes and see how far it takes you.
“Starbucks offers a varietal of dessert drinks that may, once, have been in the same room with coffee.”
“There hasn’t been a good varietal show on TV since Hee Haw.”
“I’ve eaten deep-fried whale spleen five nights in a row; it’s time to put a little varietal back in my diet.”
See? Doesn’t work. “Pinot noir is a grape varietal” doesn’t work either. Don’t say it. Don’t write it. Don’t think it. (The oenologician waves his hand.) These are not the droids you’re looking for…
Varietal – The adjectival form of “variety.” It is very nearly the case that the only times you will need to use it are to modify the words “composition” and “character.”
“Sauvignon blanc grown on fertile plains, harvested by machine a month before everyone else and at industrial crop levels, then chaptalized, yeasted, and enzymed, probably doesn’t retain much varietal character despite the desperate attempts of global beverage conglomerates to convince you otherwise by putting cute animal drawings on the labels.”
“The varietal composition of a super-Tuscan is irrelevant in comparison to the speed-to-overcompensation ratio of the modified sports coupe driven by its owner.”
There are other uses along these lines that can be correct, but if it’s not explicitly modifying a word, it is very likely that you’re using it incorrectly.
The trouble comes with the other acceptable use of “varietal,” which is to refer to a single-variety wine, and in which the word can transmogrify into a noun. That is to say: if it’s 100% saperavi, it’s a varietal wine, a varietal saperavi – note that, in both cases, “varietal” is happily nestled in its comforting and familiar position of modification – or, in shorthand, a varietal.
This is the only use of “varietal” in which a missing word-being-modified is acceptable. The only use. (Unless, of course, I’m forgetting one. Which I might be.) The Santa Margherita Pinot Grigio, for example, is a varietal wine, a/k/a a varietal pinot grigio, a/k/a a varietal, made up of the fermented pressings from P.T. Barnum’s soul. Châteauneuf-du-Pape, on the other hand, is only very rarely a varietal, but is instead almost always a blend. (Varietal Châteauneuf-du-Pape can be identified, in the absence of directly-sourced knowledge, by the mass of the bottle multiplied by the number of points the wine has received from critics who live in Maryland.)
It would, perhaps, help the ongoing confusion over these terms if even those who understand the differences would attempt to limit their use of the noun form of “varietal” and stick with alternative terms, like “single-variety” or “the first strike of a dumbed-down New World wine nomenclature that’s going to destroy centuries of European winemaking tradition unless we fight it tooth-and-bulldozer, and as long as we ignore that much of Europe has been using varietal designations on their wines for some time now with no deleterious effects for anyone.”
(See what I did there?)