You wrote “For example, Domaine Zind-Humbrecht has a Grand Cru vineyard, Hengst, and another called Clos Saint Urbain Rangen de Thann. But the former is a Gewurztraminer and the latter is a Riesling.”

No, Zind-Humbrecht uses different varities both on the Hengst and the Rangen and always states them on the labels. Same with all their Grands Crus, and same with 99% of today’s production in Alsace.

You wrote “Unless it said so on the label, you wouldn’t know — unless you took the time to memorize all 51 Grand Crus and remembered what grapes they grow.”

That’s why today 99% if not more of the growers who are on Grands Crus write the varieties on the labels.

You wrote “Maybe that’s what M. Dreiss has in mind: When you taste a Zind Humbrecht Clos Windsbuhl Grand Cru, do you really need to know it’s Gewurztraminer, or is it enough to appreciate all the qualities that slope, soil, light, temperature, stones, rain and wind have brought to the wine?”

It’s Mr Deiss, not Dreiss. He’s trying to push his own views because he “complanted” his vineyards (various varieties on the same parcel). Do we really need to know if there’s gewurz or riesling in a bottle of Rangen? Hell, yes!!! Try a gewurz on oysters or a riesling on chocolate cake and you’ll see… Or should Alsatian wine, or even DZH’s only be for die-hard wine connoisseurs?

You wrote: “My own feeling is, let me know the grape[s] or a little context. I don’t think that will rob my appreciation of the wine’s terroir. Rather, it enhances it.”

Spot on!
I’m afraid it’s a war between ‘complantation’ and ‘pure varieties” rather than between “terroir” and “varieties”. But as you rightly said, varieties are not the enemy of terroir, but exactly the contrary. What would display the Scheoenenbourg’s minerality better than riesling? Complantation with pinot gris and gewurz? Come on!

Sorry if I sounded harsh or patronising, it’s just that these matters… err, matter a lot to us Alsatian wine lovers.
And congrats on a great blog!

Santé!
Serge