(NPR) - Big, bold wines have their fans. But with the arrival of summer, make room for a bumper crop of lighter, more subtle wines.

"Low-alcohol wines are super hot right now," says wine writer Katherine Cole.

There's Txakoli, or Txakolina, wines from the Basque region of Spain, Rieslings from Germany and New York state, and Vinho Verde from Portugal, to name a few.

These wines typically hover in the 9 percent to 11 percent alcohol range. This compares to about 13 percent to 14 percent in a typical California chardonnay.

"We're seeing [from our stores] more requests for more balanced, light-bodied, lower-alcohol wines," Devon Broglie, sommelier and global wine buyer for Whole Foods, tells us. "And I see this trend gaining momentum."

So, what explains the trend? For starters, "budding wine aficionados are more cash-strapped than their predecessors," Cole says. And these same consumers also value novelty: "They want to look around the corner to new wines, made from quirkier, more obscure grapes," she says.

Cole says a Txakoli may offer more "bang for the buck than, say, an over-oaked, overpriced, higher-alcohol California chardonnay." And she says other wine grapes Americans aren't as familiar with, such as gamay noir (a high-yield grape used to make Beaujolais), are gaining traction too. One producer is a small Portland-based winery, Bow & Arrow.

There are several factors that determine alcohol levels. The climate and grape varietals play a role. And winemakers have several techniques that can manipulate alcohol concentrations.

For instance, they can halt the conversion of sugar in the grapes to alcohol, keeping more sugar in the wine. Moscato wines, which are known for a signature sweetness and have gained popularity in recent years, are a good example of that.

In other cases, winemakers use grape varietals that don't concentrate high amounts of sugar. And they can adjust how long grapes stay on the vine.

"Lower alcohol is indicative of grapes that were picked not overripe but maybe just [barely] ripe," Broglie says.