Relentless is a blend of Syrah and Petite Sirah that originates in a rugged, sloping vineyard planted in the chaparral foothills of the Vaca Mountains, along Napa Valley's drier, cooler southeast corridor. The soul of the wine, though, comes from its namesake, their longtime winemaker, Elias Fernandez, who the Shafer family honours with this proprietary blend for his relentless pursuit of quality.

As with each of their wines the Shafer team kept asking if Relentless had reached its finest expression. With this pursuit in mind the decision was made to move away from the structure of a field blend toward an approach similar to Hillside Select in which only the most compelling, refined fruit of the vintage determined the make-up of the wine.

"The ideal 2018 vintage has produced a Relentless that balances richness and vivacity. There's heft and structure along with mouth-coating flavors that go on and on. Uncork this bottle and you'll find layers of blackberry compote, red and black spice, dried black fruit, black tea, tobacco, and earthiness. All this liquid midnight comes with an undercarriage of ripe tannin that promises much more beauty and opulence in the decades ahead."
Shafer winemaker Elias Fernandez

"The 2018 Relentless is silky and polished … Ripe red/purplish berry fruit, lavender, rose petal, black pepper and sweet spice are laced into the super-expressive finish. This might be the most refined Relentless ever. 92 points."
Antonio Galloni, vinousmedia.com (October 2021)

"The 2018 Relentless tilts more towards Petite Sirah than many vintages, being a blend of 76% Syrah and 24% Petite Sirah, all aged 30 months in 100% new French oak. Scents of road tar, black olive and blackberries mark the nose, while the palate is full-bodied and framed by cedary notes, reasonably supple but tannic, then picks up an appealing licorice note on the finish. Drink to 2035. 92 points."
Joe Czerwinski, The Wine Advocate (March 2023)