Nuoc cham (nwäk CHäm)

What it means

Jeanine Cafaro of Auto-Banh Food Truck gets a lot of questions about nuoc cham. Her standard response is "Vietnamese vinegar sauce," but she realizes the shorthand doesn't fully capture the meaning of the dipping sauce in Vietnamese cuisine.

"Nuoc cham is the sauce that goes on the table at almost every meal," Jeffrey Alford and Naomi Duguid wrote in "Hot, Sour, Salty, Sweet: A Culinary Journey Through Southeast Asia." "It brings out the flavors of the food and sparks the appetite."

Like olive oil in Italy, or ranch dressing in the United States, nuoc cham is an expected condiment in Vietnam. It's used to dress noodles, season rice and marinate meat.

Considering nuoc cham's ubiquity, it's no surprise the simple elixir contains all four of the fundamental flavors name-checked by the title of Alford and Duguid's award-winning cookbook. The sauce draws its sourness from lime juice, its saltiness from fish sauce and its sweetness from sugar. That's the whole of the traditional recipe (plus water), although cooks who want to play up heat are apt to put sliced peppers or a dab of chili garlic sauce in the mix. Rice vinegar is another common addition.

Every household has its own way of making nuoc cham, so experimentation's the rule in developing a formula. But the building blocks are non-negotiable, especially the fish sauce.

"To take away fish sauce from the Vietnamese is like draining blood from a living soul, deflating a floating helium balloon or driving a nail into a tire," Diane Cu and Todd Porter, who blog at whiteonricecouple.com, wrote in an online introduction to nuoc cham. "Slowly but surely, all life would slowly cease."

Where we saw it

Auto-Banh Food Truck (Lemongrass grilled chicken sandwich, $7)

Where to buy it

If you can't find bottled nuoc cham at H&L Asian Market, you're sure to find the city's best selection of fish sauce.

Where else you can try it

Nuoc cham accompanies the banh he, a chive and coconut crepe, at Xiao Bao Biscuit; the spring rolls and green papaya salad at CO; the roasted green beans at Edmund's Oast; and the Hanoi hoagie, a lemongrass beef sandwich at The 'Wich Doctor. For a more traditional take on nuoc cham, check out Phuong Vietnamese Restaurant.