Sweet Potato and Lotus Seed Tong-sui (sweet soup), what is lotus seed
As a Cantonese, soup is so important in my daily appetite. But I don’t make savoury soup often for it usually requires meat or bones and other ingredients simmering for a long time, usually at least 2 hours and this process produces more purine which is harmful. Instead, I make vegetarian soup or tong-sui (sweet soup) which usually takes 1 hour cooking or less.
It’s crucial to cook according to the season. In this autumn-approaching-winter season, I tend to make nourishing tong-sui. Sweet potato tong-sui is one of the most popular traditional Cantonese tong-sui. It can be served all year round but I particularly like to have it in autumn and winter. The ingredients are of the most simplicity, sweet potato, ginger, rock sugar and water. Sweet potato is highly nutritious and rich in fiber. In Traditional Chinese Medicine, it promotes better bowel movement, and benefits stomach and spleen.
Beside sweet potato, snow fungus is used again in my autumn and winter tong-sui. It’s my favourite cold season tong-sui ingredient that it has been in many of my previous recipes. Get more information of this ingredient from previous post – Autumn tong-sui, snow fungus and pear soup, or simply type ‘snow fungus’ in the searching bar on my page.
Get to know lotus seed – benefit
Lotus seed is another key ingredients in this sweet soup. It’s the seed of Nelumbo nucifera, Chinese also call it ‘lotus’ which symbols ‘purity’. Lotus seed is not commonly seen in western cuisine but a very common, humble, almost all-purposed ingredient in Chinese soup and medicine. In TCM theory, lotus seeds calm the heart, benefit the kidney and digestive organs. It’s packed with vitamins, minerals and fiber and even gluten-free. It’s believe it’s suitable for most people and most body condition.
How to cook
You could sometimes find fresh lotus seeds enclosed inside its fruit pod in farmer’s markets in southern China or Southeast Asian once it’s in season. The dried seeds can be obtained in any supermarket in Chinese regions since it’s such a common ingredient. There are two types in the market – both dried, one with brown peel, sometimes with bitter germ inside, one white, which is without peel, and have germ removed mostly. The bitter germ is also with benefit. It can clear the heat in the body and calm the heart, and is suggested to have in summer. I usually don’t bother to keep them in the soup but if you don’t like it, just obtain those halved lotus seeds with germ removed in the Chinese grocery stores or Chinese pharmacy.
Lotus seeds with peel are used in Cantonese soup, especially savoury soup, with other vegetable, pork, or Chinese medicine. Those without peel are used in dessert more often, such as tong-sui, or in Chinese pastry. Lotus seeds taste starchy and creamy with a hint of delicate sweetness after cooking. Lotus seed paste is the key ingredient in mooncake, or steamed bun. In the old days, we have crystallized lotus seeds for snacks in Chinese New Year.
- Sweet potato, 600g, any type, for making the dessert more autumn alike, I use orange flesh one
- Dry white lotus seed, 50g
- Snow fungus (dry), 10g
- Ginger, 20g
- Rock sugar, 80g
- Water, 1500ml
How to do –
- Prepare the ingredients –
Sweet potato peeled, chopped in chunks;
Soak snow fungus in water for an hour till it turns soft. Change water once or twice. Then tear it apart, cut off the yellow root part with scissor, tear into small pieces. There’s no need to use a whole snow fungus, 1/3 should be good enough; (if needed, read more of this soaking and cleaning process in Autumn tong-sui, snow fungus and pear soup)
White lotus seeds washed in running water; most of the bitter germ in the seeds should have been removed. Don’t worry if you see any when cooking, just remove it or leave it. It won’t affect the taste;
Ginger sliced thickly;
2. Put them all in a big soup pot, add in 1500ml of water. Lid on and bring to boil in high heat, then simmer for 1 hour till all ingredients cooked to soft and tender;
3. Sweeten with rock sugar. Simmer for 10 more minutes till sugar melted. Heat off and let it sit for 10-20 minutes. You could slightly mash the ingredients with soup spoon for a thicker soup. Serve warm.
Note – It’s better add sugar at last, otherwise the sweet soup would taste a hint or sourness.
- 番薯 600克
- 白莲子 50克
- 雪耳 10克
- 姜片 20克
- 片糖 80克
- 水 1500毫升