Cocoa solids is a term for the nonfat component of chocolate. It may also be called cocoa powder when sold as an end product.
In contrast, the fatty component of chocolate is cocoa butter.
The separation of the two may be accomplished by a press, or by the Broma process. The resulting powder, sold as natural cocoa powder, is more reddish than the traditional "chocolate" color, and relatively low in pH, causing a bitter or acidic taste.[1] Dutch process chocolate has been treated so as to neutralize the acidity and has a milder flavor; it is also the traditional chocolate brown in color. [2],[1] Recipes where there is a lot of fat and/or sugar, such as chocolate brownies, benefit from the more intense flavor of natural cocoa, whereas applications such as chocolate milk or hot chocolate require the milder taste of Dutch process cocoa.[1]
Cocoa solids are what lends a chocolate bar its characteristic flavor and color, while cocoa butter is what provides smoothness and a low melting point. Also, cocoa solids are what contain most of the antioxidants associated with chocolate. Accordingly, health professionals recommend consuming chocolate in forms that are high in cocoa solids while low in cocoa butter, such as hot cocoa.[3]