That bitter taste and a recipe for turnip ice cream

The case for why bitter is the most interesting flavor is the theme for a new book by food writer Jennifer McLagan. "We're all programmed genetically to react negatively to bitter," McLagan tells NPR Morning Edition host Audie Cornish. 

"Bitterness can indicate a poison or something that's toxic." (This is the prevailing sentiment, although one recent study raises questions about that assumption.)
As we grow older, we start to acquire a taste for it, she notes. "Your first sip of coffee — it's so bitter,'" she says. But most people get used to that taste. And it helps that coffee perks us up. "It stimulates the nervous system," McLagan says. "So you're prepared to, like, deal with the bitterness for the benefits."
Bitterness has its own benefits, of course. "It balances things that are rich," McLagan explains. That's why her book features dishes like Pork Chops in Coffee Black Currant Sauce. "The bitterness of the coffee balances out the fat," McLagan says.
In addition to coffee, the book features common ingredients like walnuts, beer and orange rind.

Here's one of the unusual recipes from the book.

Turnip Ice Cream

8 3⁄4 ounces / 250 g turnips, about 3 medium

1 cup / 250 ml whole milk

1 cup / 250 ml whipping (35 percent fat) cream

A blade of mace, or a good pinch of freshly ground nutmeg

3 egg yolks 1⁄3 cup plus 2 teaspoons /2 1⁄2 ounces / 75 g sugar

A pinch of fine sea salt

1 tablespoon vodka

Peel and coarsely grate the turnips, then place them in a medium saucepan and add the milk, cream, and mace. Bring to a boil over medium heat, remove from the heat, cover, and let stand for 15 minutes. Taste the mixture: it should taste of turnip; if not, let stand another 10 minutes. Strain the mixture into a large measuring cup, pressing down on the turnip to extract all the liquid.

Whisk the egg yolks with the sugar and salt in a large bowl until the mixture is light and thick and the sugar is dissolved. Whisk the strained milk and cream mixture into the egg yolks, then pour into a clean saucepan. Cook over medium heat, stirring, until the mixture thickens and coats the back of a spoon. Strain into a bowl and cool quickly by placing it in a larger bowl or sink filled with cold water and ice. Stir the mixture often. When it is cool, cover and refrigerate overnight. Also, place a container for the ice cream in the freezer to get cold.

The next day, remove the ice cream mixture from the refrigerator, stir in the vodka, and then churn in an ice cream machine following the manufacturer's instructions. Transfer to the cold container and freeze until ready to serve.