"Nguyen Thi Tinh draws a sample of her 2006 vintage from a wooden vat, inhales deeply, and dips her finger into the golden-brown liquid. The verdict? A sharp nose. Nice warm hues. And the taste is, well, sour, salty and unmistakably fishy. What cognac is to France, the pungent, fermented fish sauce in Tinh's vats is to Vietnam: A national treasure that shouldn't be produced anywhere else." The Christian Science Monitor's Simon Montlake visits the island of Phu Quoc, where Vietnam's best fish sauce is made.