How to remove sand from shellfish

The basic method for removing sand from shellfish is

① Place a colander inside a container with a flat bottom, and arrange the shellfish in it so that they do not overlap.
→ To prevent reinhaling the sand that the shellfish vomits

② Put room temperature seawater (salt water) to the extent that the shellfish is slightly covered. Clams have a salinity of 3-4%; clams have a salinity of 0.5-1% (because clams live in places where seawater and freshwater mix)
→ If the water temperature is below 15°C, it will not spit out enough sand (ideally around 20°C).
→The reason for adding seawater (salt water) is to prevent the loss of amino acids other than weakening the shellfish.
Shellfish have a habit of trying to balance the osmotic pressure inside and outside the cell while they are in the water, and they make this adjustment by increasing intracellular amino acids.
→The reason why the amount of water is enough to cover the shellfish is to prevent the shellfish from dying due to lack of oxygen. The amount of oxygen that can be dissolved in water is surprisingly small, so this is a measure to prevent oxygen deficiency. (In other words, if there is air, plenty of water is fine)
③ Cover the room with newspapers, etc. to make it dark. (Leave for 3-4 hours)
→Because shellfish are usually in the sand and do not vomit sand unless it is dark. Also, depending on the book, it is written as 1 day if it is long and scattered.

*It is said that if you put a kitchen knife and a rusty kitchen knife together, sand will be removed well, but it is said to be ineffective.

From here on it's subjective.

I searched various books and the internet about removing sand from shellfish, but there were some suspicious stories, so I will write them down.

① Remove the sand with hot water (50℃). The merit is that sand removal is completed in about 15 minutes.

② Remove the salt. After removing the sand, leave it for 3 hours in the same process as removing the sand without adding seawater (salt water). It removes the saltiness and creates succinic acid, which is the umami component.

③ Clams do not need to be sanded. Clams do not take in sand inside their bodies, and in fact, sand is only on the surface of clams. Therefore, when using the shelled meat, it is unnecessary to remove the sand.