While tequila is made on an industrial scale from one type of agave only, mezcal is still made in small batches by peasant techniques from one of up to 25 of the cacti - you'll notice the difference in the added complexity, fruity, chilli flavours of mezcal.

As mezcal is not always available and you may be stuck with a choice between tequilas, the advice is to go for one that is 100 per cent agave. Others can be as much as half made with other unspecified alcohols and are best left to college students who don't care about hangovers - we're looking at you Jose Cuervo Especial.

At Agave in LKF there's a possibility of mezcal arriving soon but for the moment we try the tequilas. These are chased not with a squeeze of lime, something we often find a bit soapy, but sangrita, a mix of orange, tomato and lime juices with salt and Tabasco. It's a great finish to some smooth tequilas - we tried a flight of Tequila Corraleo, Don Julio Reposado and Herradura and found them all smooth and easy drinking. They do have Jose Cuervo Traditional, not to be confused with the swill with the yellow label, and affordable and drinkable Cuervo made with 100 per cent agave.

We may well have hit a tequila gold mine, but this is a dry well on the taco front. They don't sell them. We have a chorizo pan tostado instead and are not disappointed by the sweet combination of melted cheese, onion jam and spicy chorizo: tasty, and filling for a night of drinking but hardly authentic.

prepare to drink your dinner.

Next we move westwards to trendy Sheung Wan and newish venue Americanos. It's brushed concrete chic here but it's also another bust on the taco front, meaning, they don't sell them. The Barrio Steak Burrito is a winner, though. The rib eye steak is a generous, tender portion, wrapped in its tortilla with rice, black beans and several other garnishes. We decide not to try the other burritos at the relaxed neighbourhood spot as they betray the kitchen's Mexican-Korean mix vibe and we're looking for the authentic Mexican feel.

Mezcal is yet to reach the restaurant, but they make a mean frozen margarita. We're not so happy with their other tequila cocktail, a spicy paloma. It does taste spicy, purely from chillies the restaurant reassures us, while one of us weirdly thought he could taste cumin and the other described it as tasting of "spicy water."

the good burrito, the bad drink, and the ugly reporters.

Heading yet further west we arrive at Chino. It has a  "we don't take reservations" policy; Still, the place is full on a generally quiet evening, so perhaps it's just us who find the restaurant's 'tude an issue.

Thankfully, we were still sober enough not to shame ourselves, because we were joined at Chino by José Manuel Gutiérrez-Minera, from the Mexican consulate and his friend Fernanda Medina-Mora, who told us that to appreciate the quality of the mezcal we are drinking, we should splash a little on the bridge of flesh between thumb and forefinger and then rub it until it dries. Now we can smell the complex aromas that make for good mezcal. We try this with the star drink of the night, the Los Danzantes reposado and discover hundreds of different components to the smoky aroma. Sadly, we can't tell you what they are as we decided to try another quality test, pouring the drink from one glass to another from a height of 20 centimetres to see if a good froth forms and only managed to soak our notepad. Perhaps we weren't as sober as we thought.

This is the first place that offers the trifecta of tacos, tequila and mezcal, so we went for all three. The tacos are exquisite, especially the crispy fish and special of the day of ox tongue. It's easy to see why a Mexican such as Gutiérrez-Minera, would like the food here. But the portions are small, and pricey.

There's no arguing with the quality of the mezcal. It's a short but interesting list that includes the popular Del Maguey. These are sipping drinks, with a good length and flavours that match the oxtail taco perfectly. The couple of little bites that there are of it. The list is also just a little on the steep side. Mezcal may be delicious and small batch, but it's also a peasant agricultural product. Likewise, the tacos are not Michelin contenders, so imagine our deflated spirits when a bill for HK$1,530 arrived.

bring a fistful of dollars. Perhaps two fistfuls.

The marathon continued with a trip across the water to Caliente in Tsim Sha Tsui. We meet some Mexican food fans from the US and dig in to a down to earth menu. While our notes have become a little, let's say abstract, at this point ("Newish/Jewish/Screw a fish"), We must have been hungry as "we need food" was also scrawled in an unsteady hand across the top of our notes. Friendly staff take our somewhat convoluted order of nachos and five different combinations of five tacos each without writing anything down and amazingly bring each of five people the right order. Our American friends comment on the quality of the nachos and how rare it is that each chip has "100 per cent coverage" of toppings. The tacos were some of the very best on the whole crawl, the ingredients were fresh, flavours strong, portions big, and price reasonable. The fish taco fried to a crisp on the outside tender on the inside perfection are the best in Hong Kong at the moment.

While we gorged, we drank deeply of crisp cold Sol beer and fine Mezcal Amore, which was so smoky it could have been a whisky. Everyone enjoyed themselves immensely thanks to the great outdoor terrace, good food, and friendly relaxed service.

most magnificent of the seven.

Back over the border and on Staunton Street we slip into Cali-Mex. This is the only branch of the new seven-location chain that serves tequila. As they are not going for a premium priced market, there's no mezcal, there are plenty of tacos though. We entered the restaurant with a bit of trepidation, both of us having heard not-so-good things. But, after our first taco - and fourth shot - we decided its detractors were way off base. Aside from a very disappointing and muddy fish taco, everything we tried, from the US chipotle pulled pork to the Australian barbacoa beef, was fresh, ample, and delicious.

The ingredients are of better-than-average quality and the tortillas - the best we had on the whole crawl - are made fresh on the spot. The guacamole attracts a surcharge, but it's a generous portion.

The tequila comes with salt and lime, but for a shot that matches the quality of the food go for the higher end of the list: Patron XO Cafe (coffee flavoured), Don Julio Blanco and Don Julio Reposado.

tortillas anything but flat.

Xoco in SoHo may have the nicest interior of all we visited and certainly has the largest portions. The tacos a la plancha beef are excellent but the big strips of beef are hard to eat as single mouthfuls. The chef's 10 years of experience in Mexican kitchens also shows in the chicken taco and all the sides - the rice and beans show a real deft touch. If you think rice and beans are easy to do right you probably haven't had good rice and beans.

This place has only been open a couple of weeks when we visit, so their mezcal is still in shipment. We "make do" with Patron Silver, Herradura Reposado and 1800 Añejo. We didn't go wrong with the first two, but one of us finds the 1800 a disappointment, too sweet and one-note.

All the tequilas go well with our Sols and Bohemias - probably the best Mexican beers available in Hong Kong and we could have stayed for hours, but the blaring mariachi music started to grate and when the Gypsy Kings cover of came on we politely made our exit.

frijoles deliciosos; tacos enormes.

If any Hong Kong Mexican place fits the party mood we found ourselves in, it is Brickhouse. The tacos are famously some of the city's best, but while the toppings were innovative and delicious - The Fat Man Dancing has spiced pork belly, mango salsa and chilli mayo, The Give a Cluck uses manchego cheese with salsa fresca, salsa verde, black beans and tender chicken - the tortillas, however, were cold and stale.

Brickhouse is home to two of our favourite cocktails: The Diabla (vodka mixed with jalapeno, rasberries, pomegranate, and lemon), and The Cubano (tequila reposado, mezcal, vanilla brandy, lemon, grilled pineapple, served with a top of wood chip smoke and a volcanic salt rim). They also boast an impressive collection of tequilas and mezcals and serve the mezcal right: in an earthenware saucer with salt and an orange slice. Sadly, none of the bars we visited had the most traditional accompaniment to mezcal, salt mixed with a powder of dried worms.

We liked the drinks so much we lingered over a few more. Perhaps it was that last mezcal shot (or the 10 previous) that proved too much. Our beds have never been more welcome.

after the fiesta comes the siesta.