(SFChronicle) - There you are, you and friends on a fall afternoon, gathered in a Napa Valley tasting room. You’re primed, pumped, ready to savor the world’s best Cabs, Chardonnays and maybe a Fume Blanc or two. As you swirl and sip, you focus all your brainpower on the wine terms you’re supposed to remember: malolactic, tannin, terroir. And the flavors you’re supposed to recognize: blackberry, mocha, tobacco leaf.

At this point, one of your friends pipes up to ask the person pouring behind the bar: “Do you have any vegan wines?”

Pause. You feel a moment of panic. You wonder if, this whole time, for centuries, the deep merlot color of the world’s red wines has been more a function of sheep’s blood than grape juice. Is animal testing a new wine variable you have to know? You’ve spent hours trying to memorize Robert Parker’s wine scores. Now you have to worry about Gwyneth Paltrow’s?

Kind of, yes. Here, in one of the most famous wine regions in the world, wines advertised as being meticulously absent of all animal products are becoming a thing. That’s good news for Napa visitors seeking vegan options that have previously been hard to identify.