RETTO DISCOVERIES · 001
How a traditional Japanese process gives Moshio its golden colour, gentler salinity and quiet savoury depth.
By Robin · 16 July 2026
I’ve never thought twice about taking a pinch of salt straight.
Years of long-distance running, football and exercising in hot conditions have made me curious about different salts and how they taste. So when my wife, Mayumi, first introduced me to Moshio, taking a small pinch directly was perfectly natural for me.
I remember two things striking me straight away.
The first was its colour. Instead of the bright white I expected, Moshio was a warm beige-gold.
The second was the taste. It was salty, of course, but it did not have the sharp edge I was used to. It was much gentler and more savoury, without that immediate salty hit.
Next, I tried it on a few salad leaves. A small pinch seemed to brighten their flavour, but without overwhelming them.
That was when my busy brain started asking questions.
Not simply salt with seaweed added
When I first heard that Moshio was made with seaweed, I assumed it was sea salt mixed with pieces of dried seaweed.
I’d seen and tried different-flavoured salts before—salt with chilli, herbs, or seaweed scattered through it—and had always regarded some of them as slightly gimmicky.
But Moshio is different.
I started learning how Moshio is actually crafted.
The Moshio-making process starts with seawater drawn from the coast of Tsushima, an island between Japan and the Korean Peninsula. The seawater is first concentrated using reverse osmosis.
Sun-dried Japanese seaweeds—arame and hondawara—are then soaked in the concentrated seawater. As the seaweed soaks, some of its flavour components are drawn into the brine. The seaweed is removed before the salt crystallises.
Arame and hondawara are soaked in concentrated Tsushima seawater before the seaweed is removed, and the brine is crystallised.
The brine is then slowly boiled in open, flat pans. As water evaporates, salt crystals gradually form. The finished salt is roasted, sieved and carefully inspected.
So the seaweed is not simply sitting visibly among the finished grains.
By the time the crystals form, the seaweed has already left its mark.
What changes?
Flavour
But the first difference is not that Moshio has a powerful seaweed taste.
Moshio is not fishy, and it does not taste like eating a sheet of dried seaweed. The effect is subtler: a rounded savoury character alongside the saltiness.
The result is still salt, but with more going on underneath.
How salty is Moshio?
Moshio contains 89g of salt equivalent per 100g.
By comparison, many refined table salts contain close to 100g of salt per 100g, although the exact figure varies between products. Moshio therefore contains somewhat less salt by weight, but the difference alone does not fully explain how it tastes.
That helps us understand its gentler character, but that’s not the whole story.
How salty something tastes isn’t just about one number on a nutrition table. We experience the whole salt at once—its savoury compounds, minerals, moisture, crystal structure and texture.
My own experience is that Moshio tastes much less sharp than many ordinary salts, even though it remains, of course, a salt and should be used as one.
I’ve found that the most accurate way to describe Moshio is not as a low-sodium salt, but as:
A salt with a gentler perceived salinity and a broader savoury finish.
Colour
I admit, the warm colour was the first thing that made me suspicious.
Part of me wondered whether it had been coloured artificially to make it look more unusual.
It hasn’t.
The ingredients are simply sea salt and seaweed. The beige-golden appearance develops through the seaweed-soaking, concentration, crystallisation and roasting process.
The colour is therefore not a marketing ploy. It’s a visible clue to how the salt has been made.
Moshio’s warm beige-golden colour develops through the seaweed-soaking, crystallisation and roasting processes.
Why simple food shows it best
Moshio can be used across all sorts of everyday cooking, but I think its character is easiest to understand on uncomplicated food.
That doesn’t mean the food needs to be extraordinary. You don’t need the finest tomato grown on a sun-drenched Italian hillside.
A pinch of salt changes how we perceive sweetness, acidity and aroma. Moshio is very good at bringing those qualities forward without adding a harsh layer of saltiness.
A tomato becomes sweeter and fuller.
An egg tastes richer.
Plain rice becomes more savoury.
A salad leaf tastes more distinctly of itself.
That, to me, is the appeal. Moshio doesn’t need to turn simple food into something else. It helps you notice more of what’s already there.
A tasting experiment
Compare a ripe tomato plain, with sea salt, and with Moshio, and notice how the balance and savoury finish change.
Take a ripe tomato and cut it into three similar pieces.
Taste the first piece plain.
Add a small pinch of sea salt to the second.
Add the same small amount of Moshio to the third.
Rather than asking immediately which is “best”, notice:
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how quickly the saltiness arrives;
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whether the tomato seems sweeter or more acidic;
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whether the salt sits on top of the flavour or becomes part of it;
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how long the savoury finish remains after swallowing.
You may prefer one. You may notice only a small distinction. Taste is a personal thing.
But tasting them side by side makes the differences much easier to recognise.
Making salt worth noticing again
Salt is one of the most-used ingredients in the kitchen, which means it can easily become invisible to us.
We grab it without thinking. We expect it to do one job: make our food taste saltier.
Moshio interested me because it made ordinary old salt worth thinking about again—where it came from, how it was made, why it looked so different and what that process changed.
That curiosity is one of the reasons I began RETTO.
Japan is full of seemingly ordinary ingredients that become much more interesting when you stop and ask a few questions.
How was this made?
Why does it taste different?
What have generations of people learnt that we might have overlooked?
These are the questions I want to explore through RETTO Discoveries.
And those ingredients deserve to be noticed.
Robin
RETTO — between Japan and England