A look at the wine map of California shows a distinct geographical division between the regions known for their premium wines and those known for more affordable mass-market wines. All the top regions we know and recognize for their quality, from Napa Valley and Sonoma County north of the Bay Area to Monterey and Santa Barbara to the south, lie in California’s hills and valleys.

But those vineyards that produce the most volume, oceans of cheap and cheerful wines that come in boxes and bargain bottlings, are in the same region where California’s table grapes are grown, in the vast flat and fertile basin known as the Central Valley. Being considerably warmer in climate, the Central Valley will never excel in styles that need the cooling influence of the Pacific, such as sparkling wine, chardonnay, pinot noir, and cabernet sauvignon.

But when Central Valley vineyards are planted with heat-tolerant grapes like zinfandel or petite sirah, and farmed more rigorously, with lower yields, it’s possible to make higher-quality wines than the region has in the past. The Lodi region is the Central Valley’s leading appellation in terms of improving quality and is fast becoming a reliable source for big, strong red blends like this one. The region’s warmth gives the wines an elevated alcohol content and dried fruit flavors reminiscent of dark rum and raisin toast, and many of the wines feature a whisper of natural grape sweetness.

Gnarly Head “Double Black” Red Blend Lodi, Calif., $9.99 (regularly $12.99, sale price through July 28), PLCB Item #1335