It numbs everything the instant it touches your lips and moves down your throat. You have to drink the entire bowl because, I assume, the taste is so disgusting you wouldn't have the willpower to down it sip by sip.
The appeal of kava - made from the ground-up roots of a plant belonging to the pepper family - becomes obvious as soon as your lips go numb. Your brain also goes numb, in a Bob Marley summer love festival kind of way.
Vanuatu kava, one of the country's main exports, is famous for its strength and is known as the single malt of island kava (Fijian Kava, I'm told, is the light beer). And that you often down it in searing humidity adds nothing to the comfort level.
Kava-drinking has long been a popular custom in Vanuatu. It's a local and legal high, a relaxant that natives have long "enjoyed" after a hard day in the fields of their rural villages.
The root looks like nothing more than oversized ginger, which, I imagine, would also taste like something you'd only take if your life depended on it.
It's hard to pinpoint that acidic, repugnant kava taste. It clasps your tastebuds and triggers within you an image of sucking the resin from a leaf - that's been dipped in insecticide.
The most potent kava is found in Vanuatu's most isolated villages, the real Vanuatu where 80 per cent of the population live.
Vilvil, on Espiritu Santo, is a typical village. In former times, tribe members clad themselves in garments of pandanus flax, which they decorated with orange dye made from flowers.
These days, the 50-odd tribe members move about in faded T-shirts discarded from tourist-friendly markets. They subsist on whatever their farms can produce.
Chickens and pigs roam the village, and fields of crops include kumara, taro, bananas, pawpaws, yams, tobacco and, of course, kava.
The amount one drinks varies, but our host, Daniel, says he has had as many as 20 bowls in a night. This is extreme, he is quick to add.
The men and teenage boys have a special kava-whare; women are banned. They sit every evening, exchanging stories and drinking kava, then sleep in the back, away from their families, to nurture male solidarity.
Kava has now been transformed into a tourist commodity, with the custom popular at special kava bars and island resorts.
It is widely available at official ceremonies, such as after the inaugural Air NZ flight to Port Vila. As soon as we touched down, our attention was pointed to a large, swirling bowl of green watery liquid.
Next to it was a stack of bowls, similar to rice bowls. The message was clear: downing a bowl of kava, island-style, meant a series of successive gulps, for those of us who lack the skill of open-throating.
"How many bowls do you have a night?" I ask one of the locals. His reply - "five" - raises eyebrows, and I think, "When in Rome ... "
I almost enjoyed the first bowl, which I put down to novelty factor, but it's no walk in the park. As it numbs the mouth, the sheer taste and plant aroma cause the body and head to shudder involuntarily. An "eeeew" noise and scrunching of the face may accompany this.
By bowl three, the shudder and head-shake was gaining momentum, and I almost coughed it back up after bowl four.
The locals, who were supposedly looking after me, noticed and grabbed a gargantuan glass of orange juice as I prepared for bowl five.
I felt dizzy, floaty, but not in any discomfort. Apart from the growing area of numbness around my mouth, that is.
Bowl five was not an option. With an audience of journalists and expectant locals - all with dubious, cheeky grins on their faces - it was a necessity, and one I duly followed without regurgitating.
Within 30 minutes of landing, I had become an honorary local. I basked in the offered handshakes, and returned the ones I could see clearly.
I'd heard horror stories of kava exploits that ended in mad dreams, cold sweats and hallucinations. I had no such after-effects, but the feeling certainly lasted.
I was still floating on the bus from the airport. Still floating while taking an afternoon sea-kayak. Still floating that evening, at a function, when another bowl of kava was presented to me, the colour of which begged many questions.
Rather than the green of that morning which looked deceptively like Thai green curry, this kava resembled the water of a river most muddy, murky and manky.
Had I been drinking quasi-kava?
Quite the opposite, it emerged. Ceremonial kava is normally stronger and much more pungent than what's available in local kava bars, which is a browny grey colour.
I sampled it, and indeed, it was smoother, not quite as nausea-inducing, but still distinctly kava. I had two bowls, just to be sure.
As a responsible journalist, I can report that it took days for it to completely leave my system.
Addictive? I bought further supplies at the airport.
Air New Zealand has a weekly direct service to Vanuatu with airfares starting from $650 per person (excluding the airport departure fee).
Air New Zealand Holidays offers a range of holiday packages to Vanuatu starting from $1060 per person share twin.
To book flights and holidays see Air New Zealand link below, call 0800 737 000 or visit your nearest Air New Zealand Holidays Store.
Further information: See link to Vanuatu Tourism below.
* Derek Cheng travelled to Vanuatu courtesy of Air New Zealand.