Equipment
Ingredients
Broth and Base
- 1000 ml vegetable broth, low sodium preferred
- 15 g dried shiitake mushrooms
- 15 g dried wood ear mushrooms
- 100 g bamboo shoots, canned, drained and rinsed
- 200 g firm tofu, drained
Seasonings
- 30 ml light soy sauce
- 15 ml dark soy sauce
- 6 g ground white pepper
- 60 ml chinkiang vinegar, chinese black vinegar
Thickeners and Garnish
- 30 g cornstarch
- 45 ml water, cold, for slurry
- 1 egg, beaten well
- 5 ml sesame oil, toasted
- 15 g scallions, finely chopped
Nutrition (per serving)
Nutrition is estimated per serving. Nutrients without complete source data are omitted.
Full nutrition
- Calories
- 143 kcal
- Protein
- 9 g
- Carbohydrates
- 17 g
- Fat
- 5 g
- Fiber
- 2 g
- Sugar
- 2 g
- Sodium
- 1403 mg
- Saturated Fat
- 1 g
- Trans Fat
- 0 g
- Monounsaturated Fat
- 2 g
- Polyunsaturated Fat
- 2 g
- Cholesterol
- 47 mg
- Potassium
- 281 mg
- Calcium
- 129 mg
- Iron
- 1.9 mg
- Magnesium
- 40 mg
- Phosphorus
- 134 mg
- Zinc
- 1.2 mg
- Vitamin A
- 57 mcg
- Vitamin C
- 3 mg
- Vitamin D
- 0.4 mcg
- Vitamin E
- 0.3 mg
- Vitamin K
- 9 mcg
- Vitamin B6
- 0.2 mg
- Vitamin B12
- 0.1 mcg
- Thiamin
- 0.11 mg
- Riboflavin
- 0.19 mg
- Niacin
- 1.2 mg
- Folate
- 26 mcg
- Water
- 361 g
Sources: Aggregated Public Data, USDA FoodData Central
Method
Place the dried shiitake and wood ear mushrooms in a heatproof bowl. Pour hot water over them until submerged. Let them soak for 20 minutes until fully softened, then drain well. Snip off any tough shiitake stems.
Using a chef's knife, julienne the rehydrated shiitake mushrooms, wood ear mushrooms, bamboo shoots, and firm tofu into fine, uniform matchsticks about 5cm long.
In a large pot, bring the vegetable broth to a rolling boil over medium-high heat. The temperature should reach 100 degrees C or 212 degrees F.
Add the julienned mushrooms, bamboo shoots, light soy sauce, dark soy sauce, and ground white pepper to the boiling broth. Reduce the heat and simmer gently for 5 minutes to meld the flavors.
Carefully slide the julienned tofu into the pot. Stir very gently to avoid breaking the delicate tofu pieces, and simmer for an additional 2 minutes.
In a small bowl, mix the cornstarch and cold water until smooth. Stir the soup constantly in a circular motion, and slowly drizzle in the slurry. Allow the soup to cook for 1 to 2 minutes until noticeably thickened and glossy.
Remove the pot from the heat completely. Stir in the Chinkiang vinegar. Adding the vinegar off the heat preserves its sharp acidity.
While the soup is still piping hot but not boiling, use a ladle to slowly stir the soup in one direction, creating a gentle whirlpool. Slowly drizzle the beaten egg into the vortex. Let it sit undisturbed for 10 seconds to allow the delicate egg ribbons to set, then gently stir once.
Drizzle the toasted sesame oil over the surface and scatter the chopped scallions on top. Ladle into individual bowls and serve immediately.
Chef's Notes
- The soul of this dish relies on white pepper for its heat, not chili oil or red pepper flakes. White pepper provides a distinct, pervasive warmth that hits the back of the throat.
- Chinkiang vinegar is paramount. It is a Chinese black vinegar made from glutinous rice that offers a complex, slightly sweet, and earthy acidity. Avoid substituting with harsh distilled white vinegar; if necessary, use a 50/50 mix of rice vinegar and balsamic vinegar.
- For the most aesthetically pleasing soup, patience with your knife skills pays off. Aim to cut the tofu, bamboo shoots, and mushrooms to the exact same thickness.
- Adding the cornstarch slurry before the egg is a crucial technique. The thickened broth suspends the egg as it cooks, resulting in beautiful, feathery egg drops rather than dense sinking curds.
Storage
Refrigerator: 3 days — Store in an airtight container. The soup will thicken considerably upon cooling; thin with a splash of broth or water when reheating.
Reheating: Reheat gently on the stovetop over medium heat until just simmering. Avoid vigorous boiling as it will break the egg ribbons and thin the cornstarch structure.
Troubleshooting
The soup is not sour enough
Cause: The vinegar was added while the soup was boiling aggressively, causing the acetic acid to evaporate
Fix: Stir in an additional tablespoon of Chinkiang vinegar right before serving
Prevention: Always add the vinegar off the heat at the very end of cooking
The egg forms large, rubbery clumps instead of delicate ribbons
Cause: The broth was boiling too vigorously, or the soup was not stirred into a gentle vortex before adding the egg
Fix: Cannot be fixed
Prevention: Turn off the heat before adding the egg and ensure you pour it slowly into a moving whirlpool
The soup becomes thin and watery shortly after serving
Cause: Amylase enzymes from a tasting spoon broke down the cornstarch, or it was not cooked long enough to gelatinize
Fix: Return the soup to a simmer and stir in a small amount of fresh cornstarch slurry
Prevention: Never double-dip a tasting spoon into a starch-thickened soup
The spice level is harsh rather than warming
Cause: Using black pepper or chili flakes instead of authentic white pepper
Fix: Cannot be fixed, but adding a pinch of sugar can help balance the harshness slightly
Prevention: Use high-quality ground white pepper, which provides the traditional earthy heat
Cultural Context
Originating in the Sichuan province of China, Hot and Sour Soup (Suan La Tang) was traditionally consumed during harsh, freezing winters. The profound heat from the white pepper is believed to stimulate blood circulation and warm the body from the inside out, while the vinegar aids digestion. It perfectly embodies the Chinese culinary philosophy of balancing contrasting elements to create harmony.
