Twenty years ago, Australian chef David Thompson was eating fish dumplings and grilled squid at a restaurant in Si Racha, a small town south of Bangkok. He was offered a sauce – one that immediately made him sit up and pay attention. We’re talking, of course, about Sriracha, the Thai condiment that’s been fetishised by people across the English-speaking world.

“It was so good I asked the chef for a bottle and I asked where I could buy it; I just had to buy a case of it straight away,” Thompson says. “It was only available in one market, the main Si Racha market – it still only is, really – and we’ve been getting it ever since.”

Thompson owns Nahm, a world-famous Thai restaurant in Bangkok, and Long Chim, a small chain of more casual restaurants in Singapore, Perth, Sydney and Melbourne. He uses sriracha at all of them, though not the ubiquitous Hong Fuy brand, which is made in California by a Vietnamese expatriate, David Tran.

“Sriracha is used across Thailand in many deep-fried dishes and in seafood dishes,” Thompson says. “That’s how I first had it, and that’s how I use it.”

His preferred brand is the same one he tasted 20 years ago: Koh Loy. It’s made on a small island connected to Si Racha by bridge. (If you haven’t worked it out already, Si Racha is the probable origin of sriracha sauce – the spellings differ due to the imperfect nature of translating Thai characters to English.)

The two sauces taste quite different. Koh Loy is sweeter, thicker, richer and less spicy; the rubber mallet to Hong Fuy’s steel hammer. It’s also free from xanthan gum, a thickening agent, and sodium bisulfite and potassium sorbate, two preservatives. The only ingredients are chilli, distilled vinegar, garlic, sugar and salt.

“Sriracha is absolutely sweeping the world at the moment, but this is the one sauce that has the provenance,” Thompson says. He believes the Chinese first brought sriracha to Thailand. “I have no doubts about that – there are sauces like that all over Asia, wherever there are Chinese immigrants.”

Koh Loy is owned by a Chinese family which Thompson is on a first-name basis with. Recently he approached the family with an offer to retail Koh Loy at Long Chim. They refused for unspecified reasons, but offered to supply the same sauce under a different brand name.

Thus, Aaharn Sriracha sauce is the first release by Aylmer Aahran, Thompson’s new company which plans to popularise genuine Thai products across the world. The sauce is available at Long Chim Perth, Sydney and Melbourne for $7.95 a bottle.

“It’s the perfect condiment to almost everything,” Thompson says. “It just tastes bloody good.”