
Dark chocolate is a solid chocolate made from cocoa solids and cocoa butter, with no milk solids and less sugar than milk chocolate.
Roasted-cocoa aroma leads, over a pronounced bitterness and medium sweetness, finishing rich and mouth-coating from the cocoa butter.
Melted into warm liquids as a bulk flavour and body element, or grated over the surface as an aromatic garnish; because it is a cocoa-butter matrix it can seize on contact with small amounts of water or steam during melting, so it is worked gently and kept dry.
As a bulk base flavour it is effectively irreplaceable except by another cocoa product, since the roasted-cocoa aroma and cocoa-butter body cannot be rebuilt from unrelated ingredients; as a grated accent it swaps freely with cocoa powder or milk chocolate, with any sugar restoring the sweetness it would have added.
Milk chocolate
Milk chocolate contains added milk solids and typically more sugar with less cocoa; dark chocolate omits milk solids entirely and carries a higher proportion of cocoa solids.
A firm fat-and-sugar matrix built on cocoa mass (chocolate liquor), additional cocoa butter and sugar, dark chocolate carries no milk solids or a reduced amount relative to milk chocolate. Regulatory standards define it by minimum cocoa content: 21 CFR Part 163 in the United States and Directive 2000/36/EC in the European Union both set required proportions of cocoa solids and cocoa butter.
Keep cool and dry in a sealed wrapper away from moisture and strong odours; the cocoa butter can bloom if temperatures swing.