Espressos:Espressos in particular should be served in espresso cups to preserve their temperature and maximise flavour.

If you're lucky enough to be served one with an espresso spoon, you know you're in the hands of a real barista - the spoon helps to prevent the big drop in temperature that results when a tiny espresso is stirred with stainless steel.

Colour: According to David McKernan (above), colour in an espresso is "absolutely essential". Look for a reddish-brown colour, with speckles in the crema which show that the sugar is developed.

Smell:Aroma is a big part of coffee-tasting, and can give a sense of flavour, with floral notes and over-roasting easily detected through the nose alone, before even a sip has passed your lips.

Taste:The flavours to look for in your espresso include caramel, nut, hazelnut and vanilla flavours. Smoky, burnt or sour flavours are a no-no. There's also a marked difference in taste between Arabica and Robusta coffee beans, with Arabica generally giving a smoother taste. Country of origin will also affect the taste of an espresso.