Seven years ago I was in Hanoi on assignment for Saveur magazine. My task was to explore Hanoi-style pho for a column called “Classics.” I’d done lots of reading and research and knew about ingredients like peanut worms (sa sung), which are used for umami in pho. I arrived in the capital thinking I’d be talking to local chefs about the worms, which seemed strangely and unique to the northern pho experience. But what I didn’t expect to encounter during my Hanoi pho experiences was dam toi garlic vinegar. Just like the above photo show, the vinegar appeared in plastic containers with long spoons for people to help themselves. It was on tables at nearly every pho shop I visited. It's what Hanoians expected, like the hoisin and sriracha bottles we expect to see at pho shops in the States.
When I saw the vinegar, I was skeptical. Northern pho diehards usually don’t add lime or the like to their bowls, so where did the garlic-infused vinegar come into play? I asked a gal who was around my age, and she said she’d always had it with pho.
I sprinkled some into my beef pho and it added a wonderful, delicate bright note. The garlic didn’t hit me on the head but rather lent a pungent edge to the mild vinegary tang, which amplified the broth without taking it in a totally different direction as a squirt of lime would.