The home method

How to make sea moss gel at home

The short answer

Rinse dried sea moss until the water runs clear, soak it in cool water for twelve to twenty-four hours until it swells and softens, then blend it with clean water until smooth. It thickens in the fridge over a few hours. Keep it cold and use a clean spoon.

This is the traditional Caribbean-style home method, written out properly. We sell the gel ready-made, and we would still rather you knew how it is done — because once you have done it once, you can judge anyone who sells it to you.

Or skip the soak What sea moss actually is →

01

What you need

Four things, and the first one is the only one that matters.

Dried sea moss. Whole dried fronds, not powder. Roughly 50 g of dried moss makes something in the region of a large jar of gel, though it varies with how long you soak it and how much water you blend in. Look for material that still looks like a plant — variable in color, a bit gritty with sea salt, faintly marine. Uniform, bright, salt-free and odourless usually means it has been through a lot before it reached you.

A bowl and clean water. Cool water, not warm. You will use a lot of it rinsing.

A blender. Any blender. This is the one step that needs a machine.

A clean jar with a lid. Glass, washed and dried. This is where the gel lives and where its shelf life is decided.

Some recipes add a squeeze of lime to the blend. It brightens the taste and is traditional; it is not a preservation step and it is a mistake to use it as one.

Once it is made, here is what to do with the gel.

The method

Rinse it, more than you think
Put the dried moss in a bowl of cool water and work it with your hands. Sand and sea salt come out. Drain, refill, repeat until the water stays clear — usually three or four changes. This is the step that decides whether your gel tastes clean or tastes of the beach.
Soak for twelve to twenty-four hours
Cover it with plenty of cool water and leave it. It will swell to several times its dry volume, go pale and translucent, and turn soft and springy. Change the water once if you are soaking the full twenty-four hours.
Check that it is ready
Pick up a piece. It should be soft all the way through with no hard core, and it should bend without snapping. If it still snaps, give it longer.
Drain, and keep some of the water
Drain the moss. Keep a cup of the soaking water if you like a stronger flavor, or use clean water if you want it milder. Either works.
Blend
Put the moss in the blender with water — start with about half as much water as moss by volume — and blend until completely smooth, a minute or two. Add water a splash at a time if the blender is struggling. Stop when there are no flecks left.
Jar it and chill it
Pour it into the clean jar, lid on, and put it in the fridge. It will be loose at first and set over the next few hours. Keep it cold from here on and use a clean spoon every time.

02

The older Irish method

Worth knowing, because it is where the whole thing started and it produces something quite different.

In Irish kitchens sea moss was not blended, it was simmered. Rinsed moss went into milk or water over low heat until the gelling carbohydrates dissolved out of the fronds, the liquid was strained, and it set as it cooled into carrageen moss pudding — usually sweetened, often with a little vanilla or lemon.

The result is smoother and more like a set custard than the blended gel, and the fronds are thrown away rather than eaten. If you have ever wondered why sea moss is described as a setting agent rather than as a supplement, this is why: that is what it was for, for a very long time.

Where it goes wrong

Five failures, and what caused each one.

What happened	Why	What to do
It tastes of the beach	Not rinsed enough	Rinse until the water stays clear, three or four changes
It never set	Too much water in the blend, or not enough soaking time	Blend a new batch with less water; give the soak the full time
It is gritty	Sand left in the fronds, or blended too briefly	Rinse harder next time; blend until no flecks remain
It went sour within days	Warm water, a dirty jar, or a spoon that had been in your mouth	Cool water, a washed jar, a clean spoon, always cold
It smells sharp or fermented	It has turned	Throw it out. Do not taste it to check

Honestly

Making it vs buying it

We sell the jar, so read this knowing that.

At home

Making it yourself

Cheaper per jar and completely in your control. You choose the moss, the water and how thick it comes out. The cost is a day of waiting and a blender to wash.

Hands-on time: About 30 minutes across two days
Waiting: 12 to 24 hours of soaking
What you control: The moss, the water, the thickness
What you carry: Sourcing the dried moss, and judging when it has turned
Best if: You use a lot of it, or you enjoy the process

Ready-made

Buying it in a jar

Open it and use it. Someone else did the rinsing, the soaking and the blending, and the ingredient list is printed on the jar so you can see exactly what you got.

Hands-on time: None
Waiting: None
What you control: Flavor, size and format
What you carry: Trusting the label — so read it
Best if: You want the habit without the project

See the jars →

Yield from dried moss varies with soaking time and how much water you blend in.

Questions

Making it at home

How long do I soak sea moss?

Twelve to twenty-four hours in cool water. It is ready when the pieces are soft all the way through and bend instead of snapping.

Do I need to boil it?

Not for the blended gel. Boiling belongs to the older Irish method, where the moss is simmered and then strained out.

How much dried sea moss makes a jar of gel?

Roughly 50 g of dried moss gets you to about a large jar, but it swings a lot with soaking time and how much water you blend in. Start with less water than you think and add it gradually.

Can I use hot water to speed up the soak?

It softens faster and the gel tends to come out thinner and duller. Cool water and patience give a better result, and warm water sitting for hours is asking for trouble.

How long does homemade sea moss gel keep?

Shorter than you would like, and it depends entirely on your kitchen — the jar, the spoon, the temperature. Keep it cold, use a clean spoon, make small batches, and throw it out at the first sour smell rather than working out how many days it has been.

Can I freeze it?

People do, in ice cube trays, and it comes back thinner than it went in. If you are freezing most of a batch, make a smaller batch instead.

Contains naturally occurring iodine. If you are pregnant, nursing, or have a thyroid condition, consult your physician before use.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Now you know what you are buying.

Which is the point. Every ingredient in our jar is printed on it.

See the gel How to choose a sea moss gel →