魁北克的枫糖浆被兑了甘蔗糖，一半都不是枫的。农业部查过一次，说没问题。

Let us be clear about why this stuff is expensive, because the rest only makes sense afterwards.

Maple syrup comes from maple trees, and a maple tree will only give you sap under a very narrow set of conditions.

Early spring, thawing by day and freezing by night; it is between that freeze and that thaw that pressure inside the trunk pushes the sap out.

You collect the sap and taste it, and it is almost water — barely sweet.

Then comes the boiling.

Forty buckets of sap, boiled down, leave one bucket of syrup.

So what is truly expensive is not the raw material. It is the thirty-nine buckets of water boiled away, and a window only a few weeks long.

Canada produces most of the world’s maple syrup, and the overwhelming majority of that comes from Quebec.

There, this is not merely a business. It is a point of pride.

This year, the business had a problem.

A batch of maple syrup on supermarket shelves had been cut — and not cut a little.

The lab result is stated plainly: at least half of it was cane sugar.

Cane sugar is among the cheapest sugars in the world; maple syrup among the most expensive.

Put the first into the second: the colour is close, the thickness is close, and the price does not change.

The goods came from a Quebec producer selling under several brand names.

But the part of this worth telling is not the man who did it.

It is a more uncomfortable question: who could detect it, and who could not.

Last March, an ordinary consumer reported it, and Quebec’s agriculture ministry checked. Its conclusion: no abnormality found.

This year, a television investigation went and checked too.

What they did was almost plain: they bought five cans off a supermarket shelf and sent them to the industry’s reference laboratory for testing.

The result: all five adulterated, every can at least half cane sugar.

Five cans, and not a real one among them.

Same goods. The government could not detect it; the laboratory detected all of it.

Why?

This is worth a little science, because it explains that "could not detect it" precisely.

Maple and sugar cane run two different photosynthetic pathways.

That difference travels all the way into the sugar molecules, and shows up as a difference in carbon isotope ratios.

The maple pathway lands in roughly one range; cane lands in another, and the two are far apart.

So in principle, one isotope test and adulteration is obvious at a glance.

The problem is the threshold.

The line the industry uses to judge was set decades ago.

By that line, a can with around thirty percent cane sugar in it may still be judged "within normal range".

In other words, the testing method itself has a blind spot — and the person committing the fraud was living precisely inside it.

The later improvement was to add an internal reference: use the malic acid naturally present in the syrup as a control, compare the two, and the sensitivity rises immediately.

So the conclusion is not "it cannot be measured". The ruler was not fine enough, and nobody went and changed the ruler.

That is more worrying than the fraud itself.

A country can have the strictest industry body in the world, the most complete grading system, the strongest professional reputation.

But if the line used to check the goods has not moved in decades, then anyone committing fraud need only stay below that line to stay there legally, indefinitely.

The producer’s own account is that he did not do the cutting — the raw material arrived from his suppliers already wrong.

Here is what has happened over the past few months.

The maple producers’ industry body filed suit to take away his production quota — and in Quebec, a quota is very nearly the right to practise the trade.

A class action was filed at the Superior Court, naming him and the company in his name.

On the third of August, that class action was amended: the supermarkets that sold the syrup were named as defendants too.

Four of them, all among the largest chains in Canada.

The grounds are written without politeness: negligence, recklessness, carelessness, or serious indifference.

In plain speech: you had it on your shelves for years — you should have known.

Several of the chains have said they intend to contest, and the case still needs the court’s authorisation to proceed.

So as of today, nobody has legally been found guilty of anything.

But one thing needs no verdict.

An ordinary consumer noticed something was wrong first; the government checked once and said it was fine; and in the end a television programme paid for five cans itself and sent them to a laboratory.

Think about it:

The food you put in your mouth today — on what basis do you believe it is the thing it says it is?