We could not fit the gran reserva into our tasting, as it exceeds our cap of $100 a bottle, but the other two were included, and, needless to say, they took the top two spots. The ’06 Gravonia was our No. 1 wine and received our highest rating, the rarely awarded four stars. It was rich and oaky, yet pulsing with energy, with a coiled core of mineral flavors.

The wines are so singular that we all recognized the producer in the blind tasting. Rachel called it “historical,” and Ashley said “this is what I want when I order white Rioja.” The Gravonia was also our best value at $29.

Theoretically, a reserva like the 2003 would be a step up in concentration and complexity over the crianza, and usually it is. But 2003 was a bizarrely hot year, often resulting in wines of lower acidity than usual. This seemed true with the reserva, which was nonetheless delightful. It was our No. 2 bottle, but it did feel as if it were tiring a bit. The 2006 vintage was also a hot one, but you could not tell it by the crianza.

Aside from the long aging, the other telltale sign of a traditional Rioja is the use of American oak in its aging vessels, rather than the French oak commonly used for more modern versions. The difference may not be neon obvious, but to my taste, American oak melds better with both red and white Rioja, imparting a light coconut creaminess that seems perfectly at home with the wines.

French oak tends to offer a spicier, toasty woodiness that sticks out. I should say these are generalizations subject to many variables, including how and where the barrels were made.

The contrast in woods was evident in our No. 3 wine, the full-bodied but resonant 2014 Que Bonito Cacareaba from Benjamin Romeo’s Contador. It was a modern, much younger wine with evident flavors of French oak that the traditional-minded panel still found impressive.

Most Rioja Blancos are dominated by the viura grape, supplemented primarily with garnacha blanca and malvasia as the primary supplements. A few international varieties like chardonnay and sauvignon blanc are also permitted.