Red Bean Soup (Hong Dou Tang)

Ingredients

• 1 cup (200g) dried adzuki red beans
• 8 cups (1.9 liters) water, divided
• 1 piece dried tangerine peel (chenpi), about 5cm wide
• 80g rock sugar (about 4 small lumps), plus more to taste
• 2 pandan leaves, tied in a knot (optional but recommended)
• 1/4 tsp salt

Instructions

1. Rinse the dried adzuki beans thoroughly under cold running water, then place them in a large bowl. Cover with 4 cups of cold water and soak for at least 4 hours or overnight at room temperature. Drain and discard the soaking water.
2. Soak the dried tangerine peel in a small bowl of warm water for 10 minutes until softened. Use a spoon to scrape away and discard the white pith from the inside of the peel, as it can make the soup bitter. Set the cleaned peel aside.
3. Add the soaked and drained beans to a large pot along with the remaining 8 cups of fresh water, the cleaned tangerine peel, and the pandan leaves if using. Bring to a vigorous boil over high heat, skimming off any foam that rises to the surface during the first 5 minutes.
4. Reduce the heat to medium-low, cover the pot with a lid slightly ajar, and simmer for 60 to 75 minutes, stirring occasionally, until the beans are completely tender and some have begun to split open and thicken the broth.
5. Add the rock sugar and salt to the pot. Stir gently until the rock sugar fully dissolves, about 3 minutes. Taste the soup and adjust sweetness by adding more rock sugar one piece at a time if desired.
6. Remove and discard the tangerine peel and pandan leaves. Ladle the soup into bowls and serve hot. Alternatively, let the soup cool to room temperature and refrigerate for up to 3 days; it can also be served chilled in summer.