Chocolate is the food obtained from mixing sugar with two products derived from cocoa seeds: cocoa paste and cocoa butter. Using this basic combination, different types of chocolate are made, depending on the proportion of these elements and whether they are blended with other products, such as milk or fruit and nuts.
A good chocolate will have a very dark, shiny brown colour; it will be uniform and have no blemishes, bubbles or cracks.
It must be firm to touch —never sticky— and, when you break it, it must offer minimum resistance. If it splinters when you break it, it is too dry; and, if it is difficult to break, it is very waxy. In the mouth, it dissolves easily, continuously and completely–in other words, without any trace of granules.
The flavour must be basically bitter with just the right acidity and sweetness, and then there can be hints of pineapple, banana, vanilla, cinnamon, saffron, etc. Although, to enjoy real chocolate, you have to in essence use cocoa beans with balanced amounts of sugar, this does not happen with the chocolate we usually see, as all of the chocolate is industrialised to separate the cocoa butter and paste.
This modifies the flavour and also the quality. A good chocolate is one which —with regards to ingredients— is made from cocoa without modifying its natural substances.