Cantonese Tong Sui: a snack, a dessert, a soup (广式糖水)
Sweet Soup, or Tong Sui, is practically a cultural institution in Guangdong... though you can see similar things throughout coastal China, East Asia, and into Southeast Asia. (番薯糖水/红豆沙/冰花马蹄露)
Tongsui (糖水), or sweet soup, it's basically a cultural institution here in Guandong. It's a combination of a snack, a small meal, a refreshment, a drink, and finally, a dessert. It can be a treat that you enjoy on your way back from school, or a little "pick-me-up" you have during the long working hours at the office, or a quick nourishment you grab late in the evening.
It's mostly presented in the form of soup, and on the confusingly long array of items at tongsui shop's menu, you will see ingredients like grains, beans, nuts, fruits, herbs, eggs, dairy, etc.
And this sweet soup/drink culture? It doesn't just stop in the Cantonese food world. From costal China, to Vietnam, to Thailand, even throughout southeast Asia, this form of light and delicate sweet soup can be seen as Chè in Vietnam, or nam kang sai (น้ำแข็งใส, shaved ice with toppings) or gaeng buad (แกงบวด, coconut milk based sweet soup) in Thailand, or samalamig or ginataan in the Philippines. And they all carry similar traits: light, delicate, refreshing, and nourishing.
And here’re three little sweet soup from Cantonese cooking that you’ll find at most dessert shops.
Sweet Potato and Ginger Soup (番薯糖水)
Makes 2 servings.
Sweet Potato (红薯/番薯), ~2 small, 275g (or ~200g peeled)
Ginger, ~1 inch. Crushed
Water, 3 cups or 750ml
Slab sugar (片糖) or dark brown sugar, 20g
Process:
Peel ~2 small sweet potatoes (275g, or ~200g peeled) - also peeling the whiter outer bit, revealing the more-orange flesh below. Cut by rolling and cracking the sweet potato to get slightly irregular pieces, ~1 inch. Set aside.
Crush ~1 inch of ginger. Toast the ginger in a dry pot over medium flame until fragrant, ~1 min. Add the sweet potato, toast together for ~2-3 minutes.
Add in 3 cups (~750ml) water. Bring to a boil, then down to a simmer. Cover and simmer for 20 minutes, .
Check to make sure the sweet potato is cooked, then add in 20g of slab sugar (or dark brown sugar). Let it dissolve into the soup.
Best serve hot.
Red Bean Sweet Soup (红豆沙)
Makes 2-3 servings.
Red Adzuki Beans (红豆), 100g
Chen pi (陈皮), dried and aged tangerine peel, 5g
Water, 5 cups or 1.25L
Rock sugar (冰糖) or light brown sugar, 20g. Can go up to 30g if you prefer it sweeter
Process:
Rinse 100g of red Adzuki beans, then soak with cool water for at least 12 hours and up to 24. Strain, then transfer over to the freezer. Freeze overnight. (You can soak and freeze more for future use). After frozen, soak with hot, boiled water for ~30 minutes to thaw. Strain.
Soak 5g of chen pi (dried aged tangerine peel) in cool water for ~30 minutes to soften. Scrape off the bitter pith, then finely mince.
Add 5 cups of water and the minced chen pi to a pot. Bring to a boil, then add in the beans. Bring to a boil once again, skimming if you like. Swap the flame to medium-low, simmer for one hour with the lid cracked.
Shut off the heat, transfer the desired amount of beans to a mesh strainer (we did 80% of the beans, you can do less if you prefer it chunkier). Mash the beans in the strainer, then continuously scoop soup over the beans and continue to mash. This will leave only the shells remaining. Toss or compost the shells.
Cover and continue to simmer the soup for ~30 minutes over medium-low to your desired consistency. Add 20g of rock sugar (or light brown sugar, can go up to 30g if you prefer it sweeter). Once dissolved, the soup is done.
Can be served either hot or cold.
Water Chestnut and Egg Soup (冰花马蹄露)
Makes 2 servings.
Water chestnut (马蹄), 8 pcs
Water chestnut starch (马蹄粉) or root vegetable starch of choice (e.g. potato starch), 2 tbsp. Mixed with 2 tbsp water to make a slurry.
Water, 2 cups
Rock sugar (冰糖) or white granulated sugar, 20g
Egg, half an egg
Process:
Peel 8 water chestnuts, then rinse. Take half and finely mince, take the other half, crush, and roughly chop the crushed water chestnut.
Prepare the slurry by mixing 2 tbsp water chestnut starch (or root vegetable starch of choice) with 2 tbsp water.
Bring 2 cups of water to a boil, then add in 20g rock sugar (or white granulated sugar) and dissolve. Add in the water chestnut, bring to a boil and boil for about one minute.
Meanwhile, thoroughly whisk half an egg.
Over a medium flame now, drizzle the starch slurry into your soup bit by bit, stirring periodically. Once thickened, pour the whisked egg into the soup in a thin stream, meanwhile stirring constantly with chopsticks to create the “egg flower” effect.
Heat off and done. Best serve hot.