Easy & Quick Prawn Stock from Prawn Shells

Stock is one of the easiest base ingredients to make in the kitchen. It gives that extra sweetness and richness to soups, stir-fries, noodles, and others. I love making Chicken Stock and Pork Broth, but Prawn Stock from the remnants of Prawn Shells and Heads are even more of a treat! Just like bones, the heads and shells contain a lot of nutrients; however, unlike bones, they give out an even more unpleasant odour akin to rotten fish if they are not boiled and discarded properly.
Once I decide on a shell-less prawn dish, this prawn stock is surely next on the cooking list!
The ingredients needed are just the prawns’ shells and heads, as well as water. I kept the heads, fins (legs), and shells of the prawns. I did not include the prawn’s veins (the black thread in the back of the prawns) as they usually contain the prawn’s own waste and grit. Make sure to have extra water on hand to wash the prawns as well.

Prawn Stock Recipe
Cleaning the Prawn Shells
First, clean the prawn shells and heads. They may have come into contact with some debris while peeling. Fill a basin with water, and add in all the prawn waste. Using a spoon or spatula, stir the water. We want to be as gentle as possible to prevent breakage of the prawns’ heads. In addition, avoid washing with the bare hands as the prawns’ heads and shells contain sharp, pointed parts which could easily injure the skin.

Once they are cleaned, drain the water while straining the shells. Pick out the prawns’ heads. They should still be intact. The prawns’ essence is very concentrated in the back of their heads. This is where most of their innards are.
In a clean pestle and mortar, pound the heads lightly to slightly break them. This helps to release the essence of the prawns better when cooking the stock later. Be careful not to pound it too hard as the prawns’ juices can splash out of the mortar. If you are uncomfortable with this step, it can be skipped.

Cooking Prawn Stock
Once all the heads have been smashed, empty out the contents of the mortar into a stockpot. To cleanly wash them all down, pour some of the 650ml of water into the mortar. Give it a stir to mix, before pouring it all into the stockpot. Then, pour the rest of the water into the pot as well.
Stir the water to evenly distribute the prawn stock. Ensure that they are all floating in the water. Cover the pot, and switch on the heat to medium-high for 3 minutes. This should bring the stock to a boil.
Keep an eye on the stock once it boils, as it can overflow at any time. The moment it starts to boil over, tilt the lid so that the lid is slightly ajar. This enables steam to escape, preventing overflow. Should the lid be unable to be tilted at an angle, lay a cooking chopstick, or wooden ladle across the pan to support the lid.

As steam is very hot, avoid using ladles made from metal as they can cause burns; or plastic as they can melt.
Allow the stock to continue boiling for another 8 minutes. The fragrance of boiled seafood soup would be more prominent now.
However, it’s possible that the pot will not overflow if it is deep enough. As I have used a shallow pot for ease of demonstration, the stock attempts to overflow at the 3-minute mark. If it does not overflow, there is no need to keep the lid ajar. The stock can be boiled for another 8 minutes after the initial 3 minutes.
Stir the stock occasionally to ensure the bottom does not burn. Some scum may start forming on the surface of the stock. Remove them as necessary with a spoon, or mini-strainer.

After 8 minutes, switch off the heat. The prawn shells and heads are now a bright orange colour, while the stock itself is a slightly dull-greyish colour. It is full of seafood flavour.
Strain the bits of prawn shells and heads over a heat-proof bowl to obtain the stock. Flick the strainer over the bowl to get the stray droplets into the stock. The prawn waste is now cooked and can be discarded without the bad odour. Alternatively, they can also be composted into fertilizer for the plants in the garden.

I’ve roughly estimated the amount of water needed for this stock, but in reality, it depends very much on the size of your pot and the length of your cooking time. 11 minutes is the minimum amount of time, but it can be boiled for more than 11 minutes to fully extract all of the prawn’s essence if preferred. Be sure to add some water to account for the loss of liquid due to steam and evaporation as the prawn stock is cooking.
Storage Instructions
As seafood’s freshness tends to degrade quickly, I do not recommend storing this stock for more than a day. The prawn stock is a very delicate broth and can spoil after a day. Even freezing the stock is not recommended as the thawing process impacts the freshness too. It’s best to use it immediately once it is cooked.

Goes well with
If you’re wondering what to do with the stock, how about a Sweet Luffa Soup with Seafood Tofu? A few tablespoons can also be used to replace oyster sauce in many stir fry dishes. Do note that prawns are allergens, so they should not be cooked in meals for those who are allergic to prawns, shellfish or seafood.
Enjoy! 🙂

How to Make Prawn Stock with Heads and Shells
Equipment
- Pestle and Mortar
- Large strainer
- Stockpot/ Deep Pan
Ingredients
- 200 g prawn waste, heads and shells
- 650 ml water
Instructions
- Pour some water in a basin to wash the prawn waste. With a spoon, stir the water gently to rinse the shells and head.
- Drain the water by straining the prawns.
- Pound the prawn's heads with a pestle and mortar to extract the essences better.
- Add in all the prawns' heads and shells into a pan.
- Wash down the remnants of the prawns' heads with the water for boiling the stock into the pot.
- Give it a stir. Switch on the heat to medium and let it come to a boil. This will take 3 minutes.
- Once the stock starts to boil, tilt the lid for the steam to escape. Stir the broth gently.
- Tilt the lid and allow the stock to boil for another 8 minutes. Stir and remove the scum as necessary.
- Switch off the heat. The prawns' shells and heads has changed to a bright orange.
- Strain the stock to remove the bits and pieces of prawn shells.
- Use the prawn stock as-is within the day.
Video
Notes
Used for
- Stock for (seafood) soups, noodle soups, etc.
- Natural flavour enhancer for stir fries, etc.
Storage Instructions
- Once cooled, keep in the fridge until use.
- Not recommended to freeze or store in the fridge for more than a day.