If you read Saveur magazine, you may have seen the northern pho (pho Bac) article that I wrote for the March 2011 issue. One of the ingredients that I mentioned in the story was sa sung (Sipunculans), dried peanut earthworms that add a unique savory sweetness to the broth. My cousin Quyen, Metropole Hotel Chefs Nguyen Thanh Van and Nguyen Thi Kim Hai, along with other Hanoians that I interviewed for the story talked about using the worms for their pho broth. They spoke of cooking with sa sung in a matter of fact manner.
I’d read about sa sung in Chef Didier Corlou’s cookbook, Ma Cuisine du Vietnam, but he wasn’t clear about what the worms did to the broth. Plus, the dried worms are not available abroad.
In the Saveur story (I know, it’s terrible that my surname was misspelled but it happens), I suggested dried scallops as a substitute. They work very well. However, sa sung is a nifty ingredient that I want to highlight on this site. For those of you visiting Vietnam, it’s a great food travel souvenir. Maybe there’s a food importer and distributor who will make them available for cooks outside of Vietnam! Below is information that I’ve gathered on the dried earthworms.
They’re marine (sea) worms that were first described in 1827 by a French zoologist. There are over 140 different kinds of them, and some are teeny tiny (2 millimeters long) while other can be as long as 28 inches.
Sipuncula nudus, between 6 and 10 inches long, is the kind employed by cooks in Vietnam and Southern China, primarily in Guangong, Hainan, Guanxi and Fujian. The Chinese names include: beihai shachong (北海沙虫, north sea sandworm) and tusun (土笋, earth bamboo shoot). The worms are sometimes featured in aspic as a Chinese delicacy.
In English, Sipuncula nudus is often referred to as peanut earthworms. I suppose it’s because the worm can look like a peanut. It doesn’t have segments but has a large flask-like section with a proboscis that can retract. Think of pushing the finger of a glove inside out.
Watch this YouTube video and at minute 3:40, you’ll see Vietnamese people harvesting sa sung worms at low tide:
[Note: This video is in Vietnamese and it praises Hanoi pho, which many consider to the best. I do agree with that notion. The video reenacts a vendor selling pho with a shoulder poll set up.]
What does the worm do to pho broth?
It’s a dried marine product that’s full of umami, a deep savory-sweetness. When I add sa sung to the pot, the broth becomes remarkably fragrant. The above video says that sa sung were an old school pho broth ingredient that few people use nowadays.
I beg to differ as the Hanoians I interviewed last summer said that it’s a great workaround for MSG. Northern Vietnamese cooks add dried seafood to meat-based noodle soup broths such as bun thang, which combines pork, chicken, dried squid, and dried shrimp. It’s not as crazy as you may think.
Where do you buy sa sung?
In Hanoi, I got my stash at Dong Xuan wholesale market in the dry foodstuffs area in a building in the back of the main one. The peanut earthworms are said to be sold at regular markets but I only went to Dong Xuan. I’ve not seen them sold in the U.S. Perhaps dried peanut earthworms available at Chinese herbal shops or dry goods store? Do you know?
How do you buy the dried earthworms?
I was told to buy the brown, rather ugly sa sung as the white ones had been overly processed. The Dong Xuan vendor told me that the brown ones were local, Vietnamese ones where as the white ones where Chinese and perhaps not to be trusted. Go figure. In any event, I listened to her and purchased 100 grams for not much money. I honestly can’t remember but the sa sung weren’t costly. Once home, I frozen them in zip-top plastic bags.
What do you do with the worms?
They’re sandy and you need to roast them in a dry skillet. Use medium heat and turn and shake the skillet until you can smell the worms’s fragrance, they puff up a bit, and darken. Let them cool on a plate, then break them into sections and shake out the sand. Finally add them to your pot of pho broth.
For my usual batch of pho, I used 1/2 ounce, which is rough 8 sa sung worms. I found that the broth did not need additional yellow rock sugar.
Waaaah. I have no worms!
Don't despair. Use dried scallops as I mentioned above! They have a similar quality. I buy small, cheap ones from the refrigerated section of a Chinese market. Look for dried shrimp and you’ll find dried scallop. Mine are no wider than a dime. You’ll pay lots more for dried scallop that are the size of domino pieces.
Are you familiar with these worms in either Vietnamese or Southern Chinese cooking? Do you know of a source outside of Vietnam?