Shared from Serious Eats
Sa sung—dried peanut worms—have been described as the secret ingredient of great pho. They’re now available in the United States, so we tested them out.
Photograph: Vivian Kong
I had heard about them before; the first time I read about them was on Andrea Nguyen’s website, Viet World Kitchen, in a 2011 post titled “Pho Secret Ingredients: Dried Earthworms (Sa Sung).” At that point, I had been trying to recreate a specific bowl of pho I had grown up eating in Hong Kong, and reading about sa sung, an ingredient that was entirely unavailable in the United States, made me feel wonderful about my many, many failed attempts. It wasn’t that I was bad at making pho, I just needed some worms.
Nguyen went on to write more about sa sung in her phenomenal book The Pho Cookbook: Easy to Adventurous Recipes for Vietnam’s Favorite Soup and Noodles, for which she won a James Beard Award in 2018, including not just how to prepare them but also how to find substitutes. I planned on following her advice when I got my hands on the product Phan had promised to send over.
What arrived in the mail was a bag of what looked like ribbed finger cots—which is, of course, just another way of saying mini condoms—had been left out in the rain for a couple days and then set in a dusty shed to dry. I opened the bag and took a sniff. The aroma was pretty similar to other dried sea products, leaning more toward the heady sweetness of dried squid and cuttlefish than the broadly oceanic smell of, say, dried shrimp or finfish.
I decided to make an initial foray into worm-flavored pho by including a handful of toasted sa sung in Kenji’s pressure cooker chicken pho recipe. The resulting broth was extremely tasty, though the difference the sa sung made was hard to describe; the broth was at once a little sweeter and even more savory, maybe, but also something else that I couldn’t put my finger on.
I decided to probe more deeply.
What Are Sa Sung?
Photograph: Vicky Wasik
Nguyen’s site has a concise explanation of what the worms are, and it appears that a lot of other online sources plagiarize her copy, which we, of course, will not do here. I urge you to visit that page for her description (also, it’s an excellent web site!).
In brief, sa sung are known as Sipincula nudus or, more commonly in English, “peanut worms,” due to the appearance of their ridged exteriors when the worm is not extended. They’re marine worms that are eaten both fresh and dried, although it is only the dried form that is used to flavor broth in Vietnam. (They’re also considered a delicacy in China, and, like other Chinese delicacies, are fodder for gawping expats to write about in their hometown paper.) The worms are harvested in tidal flats, often by women, according to this article in Tuoi Tre News, the largest daily newspaper in Vietnam, and a kilogram of worms can be sold for around $15 (that article has some lovely photos of the worms in their fresh form, although they may not be for the worm-averse).