Do you like eggs with wine? How about wine IN eggs?

Sounds a bit dicey, but it’s been happening more lately as winemakers embrace concrete egg-shaped fermenters as a way to add unique flavors to their wines.

The eggs, which can be 6 feet tall or higher, have a cuteness factor not usually to be found in farming machinery. In fact, the Domaine Carneros winery in the Napa Valley was inspired to get in the seasonal spirit and had their 2,000-pound egg decorated for Easter complete with a frieze of white bunnies.

Despite appearances, there’s a serious side to this fresh approach. And it all starts with permeability.

Stainless steel tanks, which allow no oxygen in, create bright, sharp flavors. Wooden barrels, which are quite porous, create a rounder taste with flavors from the oak. The concrete egg fermenters, which fall somewhere between stainless steel and wooden barrels in permeability, offer a third option, says Domaine Carneros winemaker TJ Evans.

“What we get is a kind of an enhanced minerality and a richer texture, but without the oak,” he says. “It’s a nice little tool that fills in the niche.”