Associate Editor Claire Nesbitt tastes five consecutive vintages of Bemberg Estate Wines Malbec Gualtallary Valle de Uco El Tomillo Parcela 5 La Linterna and five vintages of Pionero, their malbec-based blend, with winemaker Daniel Pi. Parcela 5 is made with a low-intervention philosophy with wild yeasts, like all their wines, and is only released after four years. Pionero is a vintage-dependent blend of 60 to 65 percent malbec with cabernet sauvignon and cabernet franc, all from El Tomillo, the same vineyard as Parcela 5.