INGREDIENTS:
- grinded musselshells
- 7,5% (m/v) sodium alginate solution
- 2% (m/v) calcium chloride solution
PROCESS:
- clean the shells
- remove the periostracum (optional)
- grind the shells
- prepare the alginate solution
- mix and mold
- post treatment: cross-linking
CLEAN THE BYSSUS
1.
- After cooking the mussels, clean the shells removing the muscle and any residual organic part with the help of a knife
remove the periostracum (optional)
2.
To remove the dark layer that covers the shells and make them easier to grind in the following step:
- Wearing gloves, in a basin prepare a sodium hydroxide solution weighing 0,2 parts of sodium hydroxide in 10 parts of water
- Soak the shells and leave them 3-5 days in the solution. Water will turn darker as the periostracum pieces detach from the shells. The shells become more brittle.
- With the help of gloves and an abrasive pad remove the dark film that covers the shells and rinse them
- Let the shells air dry
grind the shells
3.
In sodium hydroxide pre-treatment (see step 2 – optional-), the shells become more brittle. You can also put them in the oven for a while to make them easier to grind.
- I normally use a mortar to start breaking the shells
- You would need a blender to make a finer powder. My advice is not to use an expensive one cause the shells can be tough to grind and it could get damaged
- Using strainers with different sizes of the holes you get coarser of finer powders. 1mm mesh size is good.
PREPARE THE ALGINATE SOLUTION
4.
- Pour water into a tall container with a lid and add the alginate
- Mix well with a whisk. It can help you closing the lid and shaking the container for a couple of minutes
- Leave the solution in the fridge overnight to make it homogeneous and to let out the air bubbles
MIX AND MOLD
5.
- Weight the shells powder and the alginate solution.
With 3 parts of grinded shells (e.g. 300gr) and 1 part of alginate solution (e.g. 100gr) you get a compound you can mold with your hands. Decreasing the percentage of powder (up to 1 part of shells and 1 part of alginate) you get a less dense consistency more suitable to be poured into a mold
- Mix well with a spoon to make the mixture as homogeneous as possible
- Mold the mixture into a shape
- Let it air dry. You can also use a dehydrator or put the pieces in the oven at 35°C to shorten the drying time. The more liquid is the mix, the more it will tend to crack if subjected to temperature changes
POST-TREATMENT: CROSS-LINKING
6.
- Prepare a 2% calcium chloride solution with water
- Dip the shells composite in the calcium chloride bath for 10-20min
- Let it air dry. It is now water resistant (but will absorb water if soaked)
