Tequila is one of those drinks everyone thinks they know everything about, when in fact they know only one thing - that the next morning is rough. Usually that is not the drink's fault, but the fault of a choice made in a shop for three euros.

Tequila is produced exclusively from blue agave and only in specific regions of Mexico, mainly Jalisco, with protected origin. Its history begins long before the Spanish arrived - the peoples of Mesoamerica fermented agave sap to make pulque, and the colonists brought distillation in the 16th century.

The four types that make the difference

By ageing, there are four categories. Blanco is the youngest and is bottled immediately after distillation. Reposado spends at least two months in oak barrels. Anejo ages from one to three years and has a more complex flavour. Extra anejo matures for over three years and has the richest aroma.

The two marks separating good bottles from bad ones are written straight on the label: the "100% agave" designation and the number identifying the distillery. A quality tequila does not smell purely of alcohol - it has herbal, citrus, fruity or vanilla-woody notes, and the taste is soft, not sharp. If it burns your throat, that is not character. It is a defect.

Eight cocktails for a hot evening

The classic margarita remains the basis of everything - tequila, triple sec and lime juice, with salt on the rim. Tequila sunrise was invented in Phoenix, Arizona, and owes its graded colours to the order in which it is poured, not to any mystery.

The summer part of the list is richer: a watermelon and tequila cocktail, the "guacamolita" with avocado as a variation on the margarita, the "el dorado" with lime juice, coconut and passion fruit pulp, a cocktail with pomegranate, melon and blood orange, plus a margarita with cherimoya.

The eighth is the paloma, the other classic from Jalisco and most often what Mexicans actually drink when nobody is watching.

Here the margarita usually turns up in somebody's yard with the fridge open and a supermarket bottle on the table. The difference between that version and what the bartenders describe is not the price of the venue - it is what the label says and how fresh the lime juice is.