Idli Rasam Recipe- Authentic South Indian Tomato & Tamarind Soup

Last Updated on 2 months by Neha Deshmukh

Idli Rasam Recipe: Authentic South Indian Tomato & Tamarind Soup

Hey everyone! If you’ve ever been to South India, or even just enjoyed a good South Indian meal, you know the magic of rasam. It’s more than just a soup; it’s comfort in a bowl, a digestive aid, and the perfect accompaniment to fluffy idlis. I remember the first time my grandmother made this for me when I was feeling under the weather – it instantly made everything better! Today, I’m sharing my family’s recipe for Idli Rasam, a vibrant tomato and tamarind-based soup that’s surprisingly easy to make.

Why You’ll Love This Recipe

This Idli Rasam isn’t just delicious, it’s incredibly versatile. It’s light yet flavorful, warming yet refreshing. It’s perfect for a quick lunch, a cozy dinner, or when you’re simply craving something comforting. Plus, it’s a fantastic way to use up leftover idlis! And honestly, who doesn’t love a recipe that comes together in under an hour?

Ingredients

Here’s what you’ll need to create this South Indian delight:

• 0.25 cup Toor dal (split pigeon peas) – about 50g
• 1 tablespoon Tamarind – about 15g
• 1 Tomato, chopped
• 2 Green chilies, slit
• 0.25 cup Coconut, grated – about 30g
• 1 teaspoon Rasam powder
• 0.25 teaspoon Turmeric powder – about 1.5g
• 1 pinch Sugar
• Salt, to taste
• 3 tablespoons Coriander leaves, chopped
• 1 teaspoon Ghee
• 0.5 teaspoon Mustard seeds
• 1 Red chili, dried
• 2 pinches Asafoetida (hing)
• 1 teaspoon Cumin seeds
• 1 spring Curry leaves
• 8 Idlies
• 0.5 cup Chopped onion – about 75g
• 1 cup Water (for dal) + 2 cups water (total)

Ingredient Notes

Let’s talk ingredients! A few things can really make or break a good rasam.

• Tamarind: This is key for that signature tangy flavor. I prefer using a block of tamarind and soaking it myself, but tamarind paste works in a pinch (use about 2 tablespoons).
• Toor Dal: This lentil forms the base of the rasam, giving it body and protein. Make sure it’s well-cooked and mashed for a smooth texture.
• Rasam Powder: This spice blend is what gives rasam its unique aroma and flavor. You can find pre-made rasam powder at most Indian grocery stores. Every family has their own blend, so feel free to experiment! Some blends are more peppery, others more fragrant.
• Coconut: Freshly grated coconut is best, but unsweetened desiccated coconut works too. It adds a lovely richness and subtle sweetness to the rasam.

Step-By-Step Instructions

Alright, let’s get cooking!

1. First, let’s cook the dal. Pressure cook the toor dal with 1 cup of water for 4 whistles on medium flame. Once cooked, mash it well – a smooth consistency is what we’re after.
2. Next, soak the tamarind in hot water (about 1 cup) and extract 1 cup of tamarind juice. Set this aside.
3. While the tamarind soaks, grind the coconut with ¼ cup of lukewarm water to extract coconut milk. Keep this separate as well.
4. Now, in a pot, boil the tamarind juice with an additional cup of water, chopped tomatoes, and slit green chilies for about 5 minutes. This helps the flavors meld together beautifully.
5. Add the rasam powder, turmeric, salt, and a pinch of sugar to the boiling tamarind mixture. Give it a good stir and bring it back to a boil.
6. Mix in the mashed dal and adjust the water consistency if needed. Simmer for a few minutes until the rasam looks frothy – that’s a good sign!
7. Gently stir in the coconut milk and immediately turn off the heat. This prevents the coconut milk from curdling.
8. Time for the tempering! Heat ghee in a small pan. Add mustard seeds and let them splutter. Then, add the red chili, asafoetida, cumin seeds, and curry leaves. Fry for a few seconds until fragrant. Pour this lovely tempering into the rasam.
9. Arrange the steamed idlis in serving bowls. Generously pour the hot rasam over them.
10. Garnish with chopped onions and fresh coriander leaves. Serve immediately and enjoy!

Expert Tips

• Don’t skip the tempering! It adds a crucial layer of flavor and aroma.
• Adjust the amount of green chilies to your spice preference.
• For a smoother rasam, you can strain it before adding the coconut milk.
• A little bit of sugar balances the sourness of the tamarind.

Variations

• Vegan Adaptation: Simply substitute the ghee with any vegetable oil.
• Spice Level Adjustment: Add more or fewer green chilies, or a pinch of red chili powder, to adjust the heat.
• Regional Variations: Kerala-style rasam often includes black pepper and peppercorns. Karnataka-style rasam might use a different blend of rasam powder.
• Festival Adaptations: This rasam is often made during Makar Sankranti and Pongal as part of the festive meal.

Serving Suggestions

Idli Rasam is traditionally served with idlis, but it also pairs wonderfully with rice, vada, or even just enjoyed on its own as a light soup. A side of papadums adds a nice crunchy texture.

Storage Instructions

Leftover rasam can be stored in an airtight container in the refrigerator for up to 2 days. Reheat gently on the stovetop. The flavor might intensify overnight, so you might want to add a little water when reheating.

FAQs

What is the best type of tamarind to use for rasam?

I recommend using a block of raw tamarind. It gives the most authentic flavor.

Can I make rasam without tomatoes?

Yes, you can! Rasam can be made without tomatoes, but they do add a nice sweetness and depth of flavor.

How do I adjust the sourness/spiciness of the rasam?

Adjust the amount of tamarind juice for sourness and green chilies for spiciness.

What is the purpose of adding coconut milk to rasam?

Coconut milk adds richness, creaminess, and a subtle sweetness that balances the tangy and spicy flavors.

Can I make rasam ahead of time?

You can make the rasam base ahead of time (up to the point of adding coconut milk) and store it in the refrigerator. Add the coconut milk and tempering just before serving.