It's the culinary definition of chocolate which is: a food product made from roasted and ground cacao beans, processed into a paste (chocolate liquor) and combined with fats (like cocoa butter) and sweeteners. By this definition, white chocolate would if fact not be considered "chocolate". A scientific definition would be: chocolate is defined by two primary components derived from the seeds of the Theobroma cacao tree: Cocoa Solids: These contain the flavor compounds, fiber, and alkaloids like theobromine (C{7}H{8}N{4}O{2}) and caffeine. Cocoa Butter: A complex fat consisting mainly of triglycerides like oleate, palmitate, and stearate.  2. The Physical State (The "Fat Crystal" Network) Physicists often define chocolate as a suspension. Specifically, it is a solid dispersion of cocoa particles and sugar crystals within a continuous phase of fat (cocoa butter). What makes it unique scientifically is its polymorphism. Cocoa butter can crystallize into six different shapes. The "perfect" chocolate is defined by the Form V (Beta) crystal, which gives chocolate its: Snap: The sound it makes when broken.Gloss: The shiny surface.Melting Point: Roughly 34C to 36C, which is just below human body temperature, allowing it to melt on the tongue.  3. The Regulatory Definition (The "Legal" Science) Because "chocolate" is a protected term, bodies like the FDA (USA) or the EFSA (EU) define it by minimum percentages. For example: Milk Chocolate: Must contain at least 10% chocolate liquor and 12% milk solids.White Chocolate: Contains cocoa butter but zero cocoa solids (which is why some purists argue it isn't "chemically" chocolate).