What made these wines different? Of course, each producer has its own sensibilities and intents, which alone are often enough to account for differences. These three wines also had different grape compositions. The Benanti was 100 percent carricante, while the Graci was 70 percent carricante and 30 percent catarratto, a white grape found throughout Sicily, and the Aurora was 90 percent carricante and 10 percent minnella, a rare Sicilian white found almost exclusively on Etna.

The combinations are all permitted by Etna Bianco rules, which require the wines to be at least 60 percent carricante, up to 40 percent catarratto and up to 15 percent minnella. A higher designation, Etna Bianco Superiore, requires a minimum of 80 percent carricante, and all the grapes must come from the Milo area on the east face of Etna, which is regarded as the best area for carricante.

One reader, Dan Barron of New York, found the richness of the Graci far more to his taste than the Benanti, and wondered whether the catarratto in the Graci might have accounted for that.

My guess is no. While it’s possible that the presence of catarratto added amplitude to the wine, I don’t know of anybody around Etna who considers catarratto to be particularly desirable. Notably, Graci’s higher-end Etna Bianco, Arcurìa, is 100 percent carricante and is even more gorgeous, while Salvo Foti’s superb Etna Bianco Superiore, Vigna di Milo, is likewise entirely carricante, as is Pietra Marina, Benanti’s Etna Bianco Superiore, one of Italy’s greatest whites.

Many readers were able to find the Graci, and almost everybody seemed to find that the warmer the wine got, the better it was. This is a crucial point for enjoying good white wine. Cold masks nuances as it does flaws. When you get a glass of pinot grigio from the local bar, you want it as cold as possible so that you taste nothing. But for good whites, you want access to every subtlety.

“After a half-hour at room temperature, the wine grew exponentially in mouth-feel and floral aroma,” said Smellis of Brooklyn, who drank a 2016 Etna Bianco from Murgo.

Several people noted similarities between the Etna Biancos and Muscadet, while another cited assyrtiko from Santorini. The Muscadet, grown near the Atlantic mouth of the Loire in France, seems an apt comparison, and the assyrtiko, a little-known grape from a volcanic island in the Mediterranean, maybe even more so. As Ferguson of Princeton, N.J., said acutely of the Etna Bianco, “You could taste the sea, but it was a warm Mediterranean, not the crisp Atlantic.”