How to Clean Clams

I’ve tried a lot of nonsense for cleaning clams and purging the inner gunk, and this is what actually works for me time and time again. 

Nothing ruins the greatness of a freshly steamed, briny littleneck clam like chomping down into a bunch of sand and grit.

Even though a lot of people think the clams at the grocery are already cleaned – and I’m sure they are, to some degree – if I steam them right away with just a quick rinse, I find an off-putting amount of grit and junk inside.

They definitely need to be further soaked and cleaned at home. But how?

There are a million different recommendations, the most common I see involving cornmeal or simply soaking in freshwater for 20 minutes.

I find that soaking in plain water for 20 minutes doesn’t actually do much. And ditto to the cornmeal. Cornmeal does nothing.

Below is everything I do for an enjoyable grit-free clam experience, and while the amount of gunk that comes out varies batch to batch, I always get a good amount of filth in the water.

I always think…I’m glad I didn’t eat that 😂

All you need to do is make a salt water with some precise measurements I’ll share below, and the clams will purge the gunk inside with some time.

How to get the clams home from the store

When you buy your clams from the grocery, always take them packed with ice, to keep them fresh. 

At my store, what they do is pack the clams in a mesh bag so they can breathe, then they put the mesh back into the below bag of ice:

Do not seal the bag, otherwise the clams can suffocate and die.

Not making them right away?

I like to make the clams the same day I buy them. This is the best option for freshness, but if you must, you can save them for a day.

If you want to store the clams for later: Keep them over ice in the fridge in an open container, so they can breathe. And don’t keep them longer than one day.

Check for cracks

Generally the fishmonger will only pack tightly closed clams without big chips or cracks in the shell, but occasionally they miss some.

This is an example of a clam that is best thrown away:

I know it stinks because you’ve paid for it, but it’s not worth the risk.

I will admit there have been a few times when I’ve cooked clams like these anyway if I saw them alive and out of the shell during my soak, and while they do open, they often don’t taste right.  Throw them out from the start.

As far as little chips, I usually don’t mind those right along the edge if they’re tiny.

Wash the outsides of the shell

If you have a dedicated brush, brush the outsides of all the shells under cold running water.

Honestly, I just use a paper towel most of the time.

I bunch it up and scrub along the outside, and it’s thick enough to get the filth out of the crevices on the outside.

Sidenote: this probably only applies to high quality paper towels, not the thin ones that start tearing when they get wet.

Prepare the Salt Water for Purging/Soaking

In a bowl, combine 30 grams of salt with 1000 grams of cold tap water. Ideally you don’t want the water to get warmer than about 70F even as it sits, so start it out as cold as the tap will run.

Weigh both the salt and the water if you can, but if you don’t have a scale, it’s about 2 tablespoons of salt in a liter of water (4 cups-ish).

Whisk for about 30 seconds, which should dissolve the salt in the water.

Now add the cleaned clams to the water, making sure they are submerged.

30 grams of salt in 1000 grams of water is the ratio I have found to be perfect for soaking, which I tweaked slightly from this fantastic article by Hank Shaw.

He recommends a little higher salt in the water, but I find if I go higher than this, the clams taste saltier than when I bring them home from the store, so I go slightly lower.

Let the clams sit – time is what they need

After 1 hour, the clams look like this:

A few of them have opened, and you can see they’ve released a bit of gunk into the water.

Great, but they need longer.

After 2 hours, the water will be a little gunkier, but you may also notice that the clams begin to come out of the shell.

If you look here, you can see the tube like parts coming out of the shell, which is its siphon.

Be careful moving the bowl, because as the clam goes back into the shell, it can shoot water out at you! It has happened to me, from a foot away.

After 2-3 hours, I remove the clams from the water and give them another rinse.

Here you can see some of the leftover gunk in the water:

Today’s batch is actually quite a bit less than average in terms of gunk that comes out, but I’m still glad I got all that out of my clams!

Cook the clams

The clams are now ready to cook, any way you like.

I place them in a steamer insert in my stockpot, in a single layer:

I put the lid on and start checking every few minutes after I can hear the water boiling, because I like to pull the clams that have fully opened while the others steam, so they don’t get overcooked.

As always, if there are any clams that don’t open after they’ve been steaming at a rolling boil for 5 minutes or so, they are probably dead and should be thrown out.

Enjoy your grit-free clams! Look how clean and beautiful they are:

You can use these clams with a dish like Linguine alle Vongole.

Coconut Green Curry Mussels is one of my favorite seafood recipes, and it can be made with clams as well.

See my entire Fish & Seafood recipe collection here. Happy cooking!