Chocolate is what we eat when we’re stressed. In other words, chocolate shouldn’t cause stress.

But it can when the grocery shelves hold not only our beloved semisweet chips, but chocolate labeled bittersweet, milk, white, unsweetened, German’s, baking and more.

And what’s up with all those percentages?

Even cocoa powder comes in choices: Dutch-process and natural.

Actually, the options are pretty simple, in many cases coming down to a basic question: What do you like?

First, though, let’s define the differences, thanks in part to info from the National Confectioners Association.

Unsweetened chocolate comes as billed. It has no sugar, so it’s nothing but chocolate ground from nibs (the centers of cocoa beans) and some cocoa butter. This ground mixture, called chocolate liquor or sometimes cacao mass, also may be packaged as baking chocolate. It’s very bitter, almost astringent.

Bittersweet and semisweet chocolate are where sugar starts entering the picture, along with more cocoa butter. By U.S. regulations, both bittersweet and semisweet bars or chips must contain at least 35 percent chocolate liquor. Bittersweet usually has more — at least 50 percent. Here’s also where those percentages come in: The higher the percentage, the more chocolate liquor in the bar, the deeper the flavor.

What makes up the remaining percentages? Cocoa butter and sugar, in proportions that vary with the producer. Bars labeled German’s chocolate are among the sweetest. But the famous German chocolate cake also may be made successfully with semisweet chocolate. Note that German’s chocolate has nothing to do with Germany. It was created by Samuel German in 1852, for his employer, Walter Baker & Co.

Bottom line: Bittersweet and semisweet chocolate can be used interchangeably. The determining factor is how intense a flavor you’re seeking.

Milk chocolate is made with dry milk solids, at least 12 percent. There’s more sugar, while cacao mass may be as little as 10 percent. This is almost too mild for baking, but delicious alone to savor or as the foundation of a great frosting.

WHAT’S UP WITH WHITE CHOCOLATE?

White chocolate flips the formula, showcasing cocoa butter, along with milk solids, sugar and vanilla. There’s no chocolate liquor or mass here, which causes some people to say it’s not “real” chocolate. But cocoa butter is the fat from cocoa beans, so white chocolate does come from a cocoa plant.

The likely culprit behind the confusion is the product called almond bark or coating. It looks like white chocolate, but is made with vegetable fats instead of cocoa butter.

Finally: cocoa. Mostly, recipes call for natural cocoa, which is chocolate liquor with all the cocoa butter pressed out of it. The resulting dry stuff is ground into cocoa powder that’s lighter, even reddish, as in Red Velvet Cake.

Dutch-processed cocoa starts with natural cocoa, but it’s then treated with an alkaline solution to neutralize cocoa’s natural acidity. It’s milder in flavor, but darker in appearance.

Bottom line: For recipes that don’t specify a particular cocoa, use natural cocoa. Dutch-processed may turn up in recipes that rely only on baking powder for leavening, since baking powder includes its own acid. The two cocoas are not interchangeable, so follow the recipe for optimum results.

And here’s a sweet hack: If you’re out of unsweetened chocolate, but have natural cocoa on hand, melt 1 tablespoon of butter or shortening, then stir in 3 tablespoons of cocoa powder. This is the equivalent of 1 ounce of unsweetened chocolate.

Finally, as with most ingredients, you pay for quality. In recipes with chocolate flavor front and center, such as a flourless cake, top-grade chocolate will yield the best results. Store brands may be fine for everyday chocolate-chip cookies.

STILL FEELING a little stressed? Have no fear. Here’s a recipe for chocolate frosting that will ease your mind. It uses both milk and semisweet chocolate bound with sour cream, so it’s not too sweet and lets the chocolate flavor shine.

The brown sugar makes the chocolate taste fudgier and the corn syrup makes the frosting easily spreadable and gives it a slight sheen. Use either chips or chopped bar chocolate.

LUSCIOUS, CREAMY CHOCOLATE ICING

From “BakeWise” by Shirley Corriher (Scribner, 2008)

• 12 ounces (2 cups) milk chocolate, chips or chopped
• 9 ounces (1-1/2 cups) semisweet chocolate, chips or chopped
• 2 tablespoons light brown sugar
• 1/8 teaspoon salt
• 1 teaspoon vanilla extract
• 3 tablespoons light corn syrup
• 1-1/2 cups sour cream

Place chocolate in a large microwave-safe bowl and microwave on 50 percent power in 30-second intervals, stirring after every interval, until completely melted and smooth. This will take 2 to 3 minutes total.

In a large mixing bowl, whisk together brown sugar, salt, vanilla and corn syrup. Stir in sour cream with a few strokes.

Add melted chocolate. Stir until no sour-cream streaks remain and it’s very smooth. It will be beautiful.

If it is too thin, let stand for an hour at room temperature until slightly thickened.

Makes enough to generously frost and fill one (8- or 9-inch) layer cake or 2 dozen cupcakes.

Nutritional information unavailable.