This producer shifts the needle of a famous DOCG, largely responsible for many innocuous wines, to a dial of some intrigue. A confluence of barrel and judicious lees work, beamed across a fray of almond meal, truffle, flint and mandarin. The mid-palate is nourished by a kernel of creamed cashew and nougat. The finish, impressively tenacious. Drink or hold.

Here's another pretty Riserva from San Gimignano that demonstrates the aging potential of its headline white grape Vernaccia. From a warm and sunny vintage, the 2015 Vernaccia di San Gimignano Riserva is fermented in oak and sees up to one year of aging in new barrique. Aromas of spice, toasted vanilla and honey-roasted almond are woven together with apricot and preserved lemon. Saffron, cumin and turmeric are dusted over. This is a structured, mid-weight wine with 10,000 bottles made.

This is a terrific expression from Tuscany's most important white wine appellation. The 2013 Vernaccia di San Gimignano Riserva is a medium-bodied white with deep and lasting aromas. It is fermented and aged in oak. The bouquet shows slightly oxidized notes of caramel and butterscotch backed by apricot, pine nut and light spice. Evident notes of ripe apple appear on the close. Only 8,000 bottles were produced.

Fragrant and generous, the 2012 Vernaccia di San Gimignano Riserva is a terrific white wine that gives you a clear idea of the aging potential of Tuscany's Vernaccia. This beautiful wine is redolent of dried apricot, preserved lemon, candied orange and crushed oyster shell. The wine shows more complexity than you may initially anticipate from this appellation. The finish is very long and smooth.

Here is yet another wine that shows the aging potential of Italian whites. The 2010 Vernaccia di San Gimignano Riserva offers toasted almond, stone fruit, light spice and candied orange peel. The wine successfully contrasts those heavier aromas with great crispness and balanced acidity in the mouth. This Vernaccia-based white drinks like a red wine in terms of its silly texture and long persistency.