ALEX COHEN, host:
There was a time when varieties of chocolate, the kind that goes in cakes and cookies and brownies, were fairly limited to semisweet, bittersweet and unsweetened. But now, it's all about cacao - that's a specific measure of chocolateness.
The lucky reporter on this story is Elaine Corn.
ELAINE CORN: It's no surprise that today, Alice Medrich is making something with chocolate. She chops it with a chef's knife and it crunches on her kitchen's marble slab.
Ms. ALICE MEDRICH (Author, "Bittersweet: Recipes and Tales from a Life in Chocolate"): That nice brittle snap is what chocolate makes. You can hear it crack, and it feels good between your teeth.
CORN: Medrich is pastry chef and the author of numerous award-winning cookbooks about chocolate. She just published a new tome of sweets called "Pure Dessert." But she will forever love chocolate. The pieces are small, so they won't burn, although it's hard to imagine Alice Medrich burning chocolate.
Ms. MEDRICH: Well, I wouldn't. But, you'd be surprised. I mean, I have a sixth sense about it. People are busy in their kitchen, and they don't know how easily chocolate can burn, and they burn it all the time.
CORN: That is tragic, because for some people, chocolate isn't just candy, it's an out of body experience.
Ms. MEDRICH: I've never felt personally that I needed an excuse to eat good chocolate. I think of chocolate as something that makes me feel good, that's I'm going to eat the best I can find.
CORN: But all the psychoactive theobromine in all the chocolate in the world won't fix a bittersweet episode in the kitchen, like sneaking the new high-cacao chocolate into an old recipe.
Ms. MEDRICH: Sometimes when you upgrade a recipe to use better chocolate, it doesn't necessarily work out. But that doesn't mean you throw away the recipe. If you want to use chocolate with a higher cacao content, you might have to revise that recipe.
CORN: Cacao is a thing. It's two things; it's the cocoa beans, coco powder and the coco butter. Together, they account for the total cacao percentage on the label. The rest is sugar, maybe some vanilla. The more cacao on the label, the more chocolate in the bar.
Ms. MEDRICH: I'm not sure that everybody knows what the cacao content means these days, yet. But I think people are beginning to catch on that it might mean something higher quality. I wrote about that a lot in my book "Bittersweet," which maybe more topical now than it was three years ago when it came out. I got a lot of glazed looks.
CORN: A glazed sheen is what she's looking for today. A chocolateir(ph) is part scientist and Medrich wants the answer to this question: How a chocolate with two different levels of cacao melt into the same amount of milk?
She prepares two sauces side-by-side on an eight-burner stove. A corner window kept the midday light across the contours of the chocolate dissolving into creamy lakes of desire. First, a sauce with 55 percent cacao.
Ms. MEDRICH: It actually looks like sauce. It's glossy. Oops, there's a piece or two. It looks like it would be beautiful to spoon over a dish of ice cream or a poached pear or what have you. It's gorgeous.
CORN: But the other sauce has 70 percent cacao. It looks like chocolate in kind of a bad mood.
Ms. MEDRICH: And you see that it looks a little almost curdled? That isn't a pleasant thing for sauce. I'm just going to pour a little bit more milk in there. I'm just stirring them up. Getting smoother.
CORN: Ah, a chocolate catastrophe averted. And as Alice Medrich shows that with a few tricks of the trade, there's no reason to be cowed by cacao.
For NPR News, I'm Elaine Corn, Berkeley, California.