The quality and provenance of the cocoa beans and the manufacturing process is vital just as it is for fine wines.
The country of origin & quality of the cocoa bean is far more important than the country in which chocolate is made. If your chocolate is primarily sold on the basis of the country it was made in, you are probably buying overpriced, low grade chocolate.
Ideally chocolate should contain a minimum cocoa content of 60%+ for dark and 30%+ for milk. However, just because a chocolate contains 70% cocoa does not mean it is good – if the cocoa beans, original ingredients and the production processes are not good, then you are not buying good chocolate.
Chocolate shouldn’t really contain anything you don’t recognise - so if you see an ‘e’ number, artificial preservatives or hydrogenated fats, think again...

APPEARANCE
Chocolate should be flawless, evenly coloured and a deep shade of mahogany or red. 'Black' is not necessarily an indicator of a good chocolate, it tends to indicate that the beans have been over-roasted. There should be no cracks or air pockets, streaks or sugar bloom.

AROMA
The chocolate should smell good as you unwrap it with a complex fragrance. It should be sweetly fragrant but not overpowering. You could detect vanilla, berry, caramel, roasted nuts. It is bad to have no smell at all - if you can't smell, you can't taste. Burnt, musty, chemically or medicine-y is not good.

TOUCH
It should feel silky and not sticky and should just begin to yield to the warmth of your finger.

SOUND
Take a piece and break it - it should snap cleanly - if it splinters or crumbles, that’s not good.

MOUTHFEEL
Most taste buds are on the front of the tongue which is where you should start tasting the chocolate. If it doesn't start to melt straight away this is probably a sign of poor quality. The texture should be smooth and buttery, gently dissolving into a creamy liquid filling the mouth with its complexity of flavours. It must not be grainy or 'gluey'. If it's 'waxy' or 'clacky' it sometimes means the cocoa butter has been replaced with vegetable fat - and it is not real chocolate.

FLAVOUR
Essentially chocolate is going to be bittersweet, fruity and spicy with a good balance of acidity and should be subtle rather than overpowering.

AFTERTASTE
You want flavour to linger for several minutes (good chocolate can linger for up to 45 minutes) with a clean aftertaste and no residue; and certainly not be overpoweringly sweet.

Sara Jayne Stanes is a food writer, author of 'Chocolate – the Definitive Guide' and is Chairman of the Academy of Chocolate.

<< How chocolate is made

Sara-Jayne's top tips

When eating dark chocolate look out for:

* Flawless appearance with an even colour

* A nice deep aroma

* A clean snap when breaking a bar

* A great flavour of more than just chocolate. You may be able to detect fruit, spices and other notes.