How to Test Saffron Purity at Home

The water test everyone repeats online passes some adulterated samples. Here is what actually gets sold in place of saffron, and what each home test can and cannot see.

The water test everyone repeats online passes some adulterated samples.

Here is what actually gets sold in place of saffron, and what each home test can and cannot see.

Safflower

Sold as "Mexican saffron", and the most common substitute by volume.

Safflower petals are flat and floppy where saffron stigmas are not. They are also cheap enough that the economics are obvious: the substitution pays for itself many times over at saffron prices.

In water safflower releases colour, which is exactly why it works as a substitute, and it is why colour release on its own proves nothing. A jar of water turning yellow tells you something dissolved. It does not tell you what.

Marigold petals

Cut and dried marigold petal is cheap, available everywhere, and gives a strong yellow.

Same problem as safflower for anyone testing by colour alone. Marigold is often cut into thin strips to imitate thread shape, which handles the visual objection at a glance.

The giveaway is structure rather than behaviour in water, which is the theme of this whole article.

Dyed corn silk

Corn silk is already thread-shaped, which does most of the deception before any dye is involved. Dyed to the right red, it looks convincing in a photograph and reasonable in a tin.

Of the three physical substitutes this is the one that survives a casual look best, because the shape is right to begin with. Under magnification it falls apart immediately, because corn silk has no stigma structure at all.

Artificial dyes

Tartrazine, Sudan dyes and Amaranth are the ones that turn up.

These are used two ways, and the second is the one to worry about.

The first use is colouring a non-saffron material so it passes as saffron. Crude, and usually caught by structure.

The second is colouring weak genuine saffron so it passes as strong. Everything in the tin is saffron. It is simply worth less than it looks, and a dye has closed the gap. Microscopy will not catch this, because the structure is genuine. Only a laboratory looking for the dye itself will.

No home test finds these reliably. HPLC does.

Moisture loading

This one is not adulteration in the usual sense and it still costs you money.

ISO 3632 sets a moisture maximum of 12 percent. Saffron carrying more water than it should weighs more per thread. You get fewer threads for your gram and each one is a little weaker. Nothing foreign has been added. You have bought water at saffron prices.

It is also the easiest to do accidentally. Saffron pulls moisture out of a humid room, so poor storage anywhere in the chain produces the same result as deliberate loading.

The moisture figure on a lab report is what catches it. There is no home version of this test.

The trumpet

The single most useful thing you can do at home costs the price of a cheap magnifier.

A genuine saffron stigma is trumpet-shaped at one end, flaring out. Safflower, marigold petal and corn silk do not have that structure, because they are not stigmas. Under magnification the difference is obvious once you have seen it, and it does not depend on judging a colour or timing a soak.

This is the test worth learning. It is structural, so a dye cannot defeat it, and it takes about ten seconds per sample.

What the water test really tells you

Place 3-4 threads in a glass of cold water and watch for 10-15 minutes. Genuine saffron releases colour slowly and the thread keeps its red. Many fakes release colour fast and go pale.

That is a real signal and it catches the crude cases. What it misses:

• Safflower and marigold, which also release colour, just differently.
• Any dyed material where the dye is doing the work.
• Genuine saffron that is simply weak, which passes the water test and fails on crocin.
• Moisture loading, which the test cannot see at all.

So run it, but treat a pass as the beginning rather than the end. The test is good at excluding the worst material and poor at confirming the best.

The baking soda test

Add a pinch of baking soda to the water from the test above. Genuine saffron turns it a bright golden yellow. Some adulterated samples turn it red, green or a murky brown, as the alkali reacts with a synthetic pigment.

Like the water test, this catches a crude dye and is blind to everything else. It says nothing about structure, and nothing about a weak genuine batch.

The rub test

Rub a single thread between your fingers. A genuine stigma stains your fingers golden yellow and softens without crumbling. A dyed thread often bleeds colour quickly and breaks up.

This one is closer to the magnifier than to the water test, because it reads the material rather than its colour. It is still a rough version of what magnification does properly.

Two habits that beat any single test

Buy from someone who will name the lot, and read the three ISO 3632 numbers on the report for that lot. How to read one.

Structure, potency and dyes are three separate questions and no single check answers all three. A magnifier settles structure at home. The crocin, picrocrocin and safranal values settle potency. HPLC settles dyes, and only a lab can run it.

A note on price as a signal

Price is not a test, but it is evidence.

160 to 180 flowers make one gram, every one picked and separated by hand. A listing priced where that labour cannot possibly have happened is describing a different product, whatever the photographs show. The adulterants on this page exist because the gap between the real cost and the advertised price has to be filled with something.

That does not mean an expensive listing is genuine. It means a very cheap one has already answered the question.

What actually settles it

For structure, a magnifier. For potency, the crocin, picrocrocin and safranal values on a lab report. For dyes, HPLC.

Between them those three cover every case above. Any one of them alone leaves a gap, and the gap is where the money is.

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