If you're into cocktails, the fresh and inventive cocktails, you're probably drinking something that Shakespeare sipped -- verjuice (also known as verjus). It's a liquid that disappeared for centuries and now is back big time with bartenders and in chefs' kitchens.

The man leading the pack in production is California winemaker and owner of Bonny Doon Vineyard Randall Grahm -- he makes verjus de cigare.

Lynne Rossetto Kasper: What is verjuice?

Randall Grahm

Randall Grahm: Verjuice is literally green juice; it's grape juice that's harvested from immature grapes. It's exceptionally tart, not so sweet and it's brilliant in so many ways.

For one thing, it's a lovely salvage operation for something that one is going to do in the vineyard anyway. When you thin your vineyard, instead of dropping the fruit on the ground, you harvest it instead and use it in cooking, as a condiment or as a cocktail -- in a lot of ways, in fact. It's a really lovely, elegant application of what would otherwise be something you'd do out of necessity.

LRK: I understand that we have not made verjuice much in this country because our techniques for growing grapes are different than the Europeans'?

RG: Basically we grow grapes the same way -- grapes grow the way they do all over the world. But Europeans in many great appellations are very fastidious about thinning their crops to get the intensity they need. The reason they have to thin is often they're growing grapes in very marginal areas and they really struggle to ripen.

Whereas in California, our grapes generally don't have to struggle to do much of anything. So therefore we haven't really been in the habit of thinning our grapes as much. In the last few years, growers have gotten a lot more quality-conscious and it's not such an alien concept to actually thin your vineyard.

LRK: So the idea is that by thinning the vineyard, you're getting higher quality grapes and higher quality wine? So now they've got the green grapes to make the verjuice.

RG: Exactly. Still, not everyone has flocked to the idea of making verjuice. It's kind of a pain in the neck. We don't see the world just all at once deciding to make verjuice. It's a little bit of a hassle -- it occurs right during harvest, so bottling grape juice right before you're about to make wine is kind of a pain for some people. But it's worth it if you can pull it off.

One of the issues with verjuice, the biggest issue from a production standpoint, is keeping it sterile and keeping the yeast out of it. When you're making the verjuice, if you have any yeast in the bottle, you're going to have an explosive situation at some point. During harvest, there's lots of yeast floating around the winery, so it's a little bit perilous for some.

LRK: How do we use it?

RG: Our verjuice, which we make from (red) grenache grapes is actually quite green because we've harvested it just as the bunches are about to turn color. It's still quite green, and ours is a little bit sweeter than traditional verjuice. Traditional verjuice is exceptionally tart, almost like a mild vinegar, so ours isn't quite that tart. You can actually consume it on its own, although I think it's a little bit better if you mix it with sparkling water, light beer or something like that. You can use it in salads, you can use it for reductions, or any time you might use citrus, it would be a good substitute.

LRK: I love the idea of making a spritzer with it.

RG: My 9-year-old daughter thinks it's one of the brilliant concoctions in the world.

LRK: What should we look for when we buy it?

RG: Fresh verjuice. You don't want verjuice that's been hanging around for years (although likely you won't find old verjuice; it will have probably exploded by then). Of course, when you buy it, after you open it, it's fine; it's very stable. But once you open it, definitely put it in the fridge. That's something you really want to do as much as you would with apple juice or orange juice.

Lynne Rossetto Kasper
Lynne Rossetto Kasper has won numerous awards as host of The Splendid Table, including two James Beard Foundation Awards (1998, 2008) for Best National Radio Show on Food, five Clarion Awards (2007, 2008, 2009, 2010, 2014) from Women in Communication, and a Gracie Allen Award in 2000 for Best Syndicated Talk Show.