A moraine, according to the Oxford English Dictionary, is “a mound, ridge, or other feature consisting of debris that has been carried and deposited by a glacier or ice sheet, usually at its sides or extremity; the till or similar material forming such a deposit.”
And morainic subsoils are part of what makes the vineyards at Sansonina so special.
That’s a photo, snapped last week, of the morainic material — debris of an ancient glacier — that you find as you walk through the rows. I actually dug those up myself from the top soil, which you can see in the photo below.
Earlier this year, I translated the first part of Professor Attilio Scienza’s essay on the origins of the morainic subsoils at Sansonina (check it out here). In the piece, he describes the Würm, “the fourth and last phase of the cooling of the earth. It was a classic example of the erosion and accumulation of detritus that the glaciers left behind as they retreated from the most barren areas of the Alps.”
In the case of Lugana, where Sansonina is located, the same glacier that formed what is now Lake Garda also pushed and accumulated debris south of the lake.
At Sansonina, the presence of morainic subsoil is particularly high — higher than in most parts of the appellation. That’s why the Zenato family decided to plant Merlot, Cabernet Sauvignon, and Cabernet Sauvignon Franc there: Because the soils are very similar to Bordeaux’s right bank, where the same grape varieties are planted, with a predominance of Merlot just like at Sansonina.
The stony nature of the soil makes it drain well. And that means that the vines will undergo what is called “hydric stress” as they struggle to find the water table below the layer of morainic material. As a result, they produce much richer fruit. And it’s just one of the things that makes this particular growing site, surrounded by white grape plantings, an ideal place for Merlot — a red from the land of whites.