Looking up from the extensive wine list, I ordered a glass of Merlot. An easy and safe choice, I thought.

“I’ll go for a Xinomavro,” said my Greek friend.

This, you’ll understand, was a case of being seriously upstaged. Let’s face it. I’m the one who writes from time to time about wine. But the Xinomavro grape had really never crossed my horizon. It turns out some British supermarkets have been selling Xinomavro wines for a year or two now, usually as a single varietal (so 100% Xinomavro), but also wines which offset the Xinomavro with a lacing of Syrah.

Xinomavro is evidently one of those up and coming grape types that drinkers are beginning to notice. Devotees praise the complex, powerful appeal of Xinomavro red wines, often comparing the best of them with the bold reds of Piedmont made from the Nebbiolo grape.

With more and more wine drinkers, especially in bar and bistro settings, now choosing wines by grape type rather than provenance, there’s a growing interest in under-the-radar varietals. Some, like the white Picpoul grape, have shifted from being offbeat to mainstream in just a couple of years.

The notion of ordering wine by the grape type barely existed half-a-century ago, but it gained currency during the California wine boom of the 1970s as leading wineries promoted wines made from such distinguished grapes as Cabernet Sauvignon and Chardonnay by using the respective grape names.

Subsequently, other wine-growing regions in the English-speaking world — notably Australia, New Zealand and South Africa — followed suit. Thus in Britain supermarket shelves are now full of New Zealand Sauvignon Blanc, Australian Shiraz and South African Chenin Blanc.

Critics of the branding of wines by grape type are quick to point out that many of the Old World’s most distinguished wines are critically dependent on a mixture of grapes.