Ingredients for Purple Sweet Potato Dessert Soup

To make a delicious pot of purple sweet potato dessert soup for 3 - 4 people, prepare your ingredients in 3 groups: the sticky potato balls, the sweet soup base, and the coconut milk. Prep time is about 15 minutes, with 30 - 40 minutes of cooking.

Ingredients for sticky purple sweet potato balls

Ingredients for the sweet soup base and coconut milk

How to Make Sticky Purple Sweet Potato Balls

This process has 5 simple steps to keep the balls chewy while preserving their natural purple color:

Steam and mash the purple sweet potato

Peel, cut into small chunks, and steam until cooked, about 10 - 15 minutes. Mash while still warm, then let cool slightly before mixing in the starch.

Knead the dough and shape the balls

Sift tapioca starch into the mashed potato, adding warm water a spoonful at a time if too dry. Knead until smooth and pliable, not sticky, then roll into small, even balls.

Boil the potato balls

Drop the balls into vigorously boiling water. Once they float, boil 1 - 2 minutes more, then transfer immediately to ice water so they firm up without sticking together.

Cook the sugar syrup and coconut milk

Boil 700 ml water with sugar, pandan leaves, and ginger slices for fragrance. Cook the coconut milk separately with a pinch of salt over low heat, avoiding a hard boil so it doesn't separate.

Finish the dessert soup

Add the potato balls to the sugar syrup and simmer 2 minutes to absorb flavor. Ladle into bowls, top with coconut milk, and sprinkle with toasted sesame seeds.

How to Make Purple Sweet Potato Dessert Soup Using Sweet Potato Powder

Many wonder whether finely ground potato powder makes balls with authentic taste - the video below answers that fully.

Pure purple sweet potato powder skips the peeling, steaming, and mashing steps entirely, making it ideal for food businesses optimizing prep time. 

Mixing ratio for purple sweet potato powder

Mix 40 - 60 g pure purple sweet potato powder with 80 - 100 g tapioca starch, then gradually add warm water, kneading until smooth and pliable - don't pour water in all at once, or the dough turns too wet.

Notes for using purple sweet potato powder

• Test - boil first: Boil one sample ball to check texture and color. Crumbly → add more starch. Too firm → add a touch more warm water.

• Choose pure powder: Pick powder ground from fresh vegetables with no added coloring for a naturally fragrant, vibrant purple result.

Tips for Perfect Purple Sweet Potato Dessert Soup 

• Prevent balls from falling apart: Don't drop them in before a vigorous boil; avoid stirring too hard. If dough is wet, sift in more starch before shaping.

• Prevent balls from getting too firm: Don't overuse tapioca starch. Remove balls 1 - 2 minutes after they float to keep them soft and chewy.

• Keep the purple color vivid and soup clear: Steam rather than boil the potato to avoid excess water absorption. Boil and ice-bath the balls separately before adding to the syrup.

• Prevent coconut milk from separating: Cook on very low heat, stir gently, and remove from heat as soon as it thickens - never let it hard-boil.

Variations and Storage

Cook with steamed mung beans or tapioca pearls for extra richness and chewiness. You can also add yellow sweet potato pearls or refreshing grass jelly to make the dessert more colorful and refreshing. 

What pairs well with purple sweet potato dessert soup?

Steamed mung beans or tapioca pearls add extra chewiness. Yellow sweet potato balls or crunchy grass jelly add color and a refreshing crunch.

How to store cooked dessert soup

Cool completely, store airtight in the fridge for 1 - 2 days. Keep coconut milk separate and add it only when serving to prevent souring.

How to freeze uncooked potato balls

Space the raw balls out on a tray and freeze until firm, then transfer to a zip-top bag for up to a month. Boil straight from frozen - no need to thaw.

We hope this detailed recipe gives you the confidence to make this refreshing purple sweet potato dessert soup for your whole family. Don't be afraid to experiment with convenient ingredients for consistently soft, chewy, fragrant results!

Frequently Asked Questions

Is tapioca starch mandatory for this dessert soup?

Yes - it's the core ingredient giving the balls their chewy texture. Sift it in gradually to adjust for the potato's moisture.

Can I use purple sweet potato powder instead of fresh potato?

Yes - just mix with warm water and tapioca starch, kneading until pliable. Test-boil one sample ball first to fine-tune water amount.

Why do potato balls turn out too firm or fall apart?

Too firm = too much starch or over-boiling. Falling apart = dough too wet or dropped in before a full boil.

How long does purple sweet potato dessert soup keep in the fridge?

Up to 1 - 2 days in an airtight container - discard if you notice sourness, sliminess, or off odors.