OTTAWA -- Watch out, mock maple syrup makers: it's about to get a lot harder to pass off a knockoff as the bona-fide Canadian breakfast-table staple.

After more than a decade of talks among governments, food regulators and the industry, new rules are being adopted across North America to ensure consumers have a better idea of what kind of maple syrup they're buying.

The changes, which will come into effect over the next two years, will harmonize the grading system for maple syrup produced in Canada and the United States.

The Canadian Food Inspection Agency is also adopting a new system for classing pure maple syrup by colour.

And labels will include new "flavour descriptors" so consumers can get a better idea of how the various shades of syrup are likely to vary in taste.

"The intensity of the taste varies as you move from the lightest syrup, which is delicate, to the darkest syrup, which is more of a strong taste," said Dave Chapeskie, executive director of the International Maple Syrup Institute.

The institute, based in Spencerville, Ont., a 45-minute drive southwest of Ottawa, was established in 1975 by producers, packers and equipment manufacturers to help promote and protect the maple syrup industry.

Maple syrup comes in four colour grades ranging from light "golden" to dark -- easy enough to determine through a clear glass bottle, but not so much when the liquid is in an opaque container.

No matter the colour, it will all be marked as Grade A maple syrup, unless it's classified as "Processing Grade," which is still pure and edible, but may contain "minimal food quality defects."

Sen. Nancy Greene Raine said the new regulations would also help marketers of pure maple products crack down on fraudsters who sell maple syrup that is often little more than flavoured sugar water.

"If you've ever been to a street market in Paris, for example, some of them have signs advertising 'pure Canadian maple syrup,' when what they are selling doesn't actually contain much maple syrup at all," she said.

"It's mostly sugar water. They won't be able to do that anymore. It's fraud."

The amended regulations include a standard definition of "pure maple syrup" that's designed to help consumers distinguish between what's real and what's fake.

Canada produces 84 per cent of the world's maple syrup, mainly in Quebec, Ontario and New Brunswick.

The rest comes from producers in 12 states south of the border.

For Canadian producers and spin-off businesses, the industry is worth about $1 billion.

The next big question for the industry is to determine which grade of syrup has more nutritional value: the light, delicately flavoured version, or the darker one.

Lighter syrup is made in the early part of the tree sapping season and consists of a sucrose sugar, which contains one less molecule than its darker counterpart, explained Ray Bonenberg, president of the Ontario Maple Syrup Producers Association.

The light sap comes as "the tree is waking up" from the winter freeze, said Bonenberg.

As winter turns to spring, daytime temperatures turn warmer, which brings more minerals and vitamins out of the tree, producing a darker, fructose sap, which changes the colour of the syrup.

It takes 45 litres of maple sap to produce a single litre of syrup, regardless of when the sap is taken from the tree.

Researchers in Quebec are studying whether the colour change makes a nutritional difference, said Chapeskie.

Until they make that determination, consumers can choose their syrup based on taste, and how they plan to use it, said Greene Raine.

"It's a little bit like wine," said the senator, who added she pours maple syrup over everything from ice cream to yogurt.

"They taste differently and you use them for different purposes."