Chocolate: Buying, Storing, and Baking With It

Chocolate is cocoa solids, cocoa butter, and sugar in different ratios. Bittersweet and semisweet sit around 60 to 70 percent cocoa and are the standard for cookies and ganache. Unsweetened is 100 percent solids and butter, used with recipe-adjusted sugar. Milk chocolate adds milk powder and more sugar, sweeter, softer, and it burns more easily. White chocolate contains no cocoa solids at all, only cocoa butter, sugar, and milk, which is why it is not legally chocolate and why it scorches so fast.

Cocoa powder comes in natural, acidic and fruity, and Dutch-processed, neutralized and dark. They do not swap blindly in baking: the type affects which leavening works, so follow what the recipe calls for.

Read two things: the percentage and the ingredient list. A 70 percent bar whose first ingredient is sugar is candy; cocoa butter should be in the list, and vegetable fat instead of cocoa butter means a compound coating that never behaves like chocolate in baking. For chips, the stabilizers that hold the chip shape also resist melting, which is why bars melt better than chips for ganache and sauces.

For eating, taste is taste, buy what you like. For baking, the recipe's percentage matters, a 60 percent and an 85 percent bar are not interchangeable without adjusting sugar.

Chocolate keeps best at a steady room temperature, 60 to 70 F (15 to 21 C), dark and dry, sealed against pantry odors, which cocoa butter absorbs readily. Dark chocolate keeps 1 to 2 years this way, milk and white 6 to 12 months, because their milk fat goes stale sooner. Refrigeration is for hot climates only, sealed airtight, and the bar must come back to room temperature sealed, or condensation sugars on the surface.

The white dusty or streaky film is bloom, fat or sugar crystals migrating to the surface. Bloomed chocolate looks old and is completely safe, and once melted it usually re-emulsifies, though bloom-fat chocolate is best used in baked things rather than for coating.

Melt it low and slow, in short microwave bursts at 50 percent power, stirring between each, or over a water bath where the bowl never touches the simmering water. Water is chocolate's enemy: one drop of water seizing melted chocolate into a grainy paste, and once seized it will not come back for coatings. If it seizes in a sauce context, whisking in warm cream or milk rescues it as ganache.

Chopping from a bar gives the most even melt, and tempering, precise heating and cooling to set the cocoa butter glossy, only matters for dipped candies that must snap and shine at room temperature. For brownies, cookies, and sauces, skip the tempering, nobody can tell.

• Cocoa powder for baking chocolate: 3 tablespoons cocoa plus 1 tablespoon butter or oil replaces 1 ounce of unsweetened chocolate in baked goods.
• Semi-sweet for bittersweet: swap one to one, the result is a touch sweeter, cut the recipe sugar by a tablespoon per ounce if you care.
• Carob: a caffeine free stand-in with a maltier flavor, swaps one to one by weight in brownies, though the color and flavor are unmistakably not chocolate, and there is no shame in that being a dealbreaker.