Fans of hazelnut spread Nutella have gone nuts after its manufacturer tampered with the tried-and-true recipe, amid a search for new sources of hazelnuts.

The secretly made changes to Nutella’s recipe were exposed this week by German consumer group Hamburg Consumer Protection Centre.

However, while the maker, Ferrero, admitted the recipe has been tweaked offshore, it reassured The New Daily this would not affect Australian customers buying Nutella made locally.

The German group revealed Nutella had increased the quantity of its skim milk powder, making the pantry staple chocolate spread lighter in colour.

It also noted a small increase in sugar content – 56.3 per cent, up from 55.9 per cent. Meanwhile, cocoa slipped back in the list of ingredients.

Outraged customers took to social media to start the hashtag #boycottNutella and #Nutellagate.

Ferrero denied the amount of sugar had increased, dismissing any suggestion that the recipe change was a cost-cutting move.

Nutella customers were outraged by the secret change to its recipe. Photo: Getty

“The fine-tuning is only minimal in relation to the whole product. All relevant nutritional aspects remain similar,” a Ferrero spokeswoman told The New Daily.

“The nutritional facts show only small differences per 100 grams. At portion level there is basically no change.

“Whey powder, a milk derivative, has been replaced with a little increase of the already present skimmed milk powder. Quality and sourcing of all other Nutella ingredients remain the same.

“It is an international change, which does not affect Nutella product made in Australia.”

The Nutella found on Australian and New Zealand shelves has been manufactured in New South Wales since the late 1970s.

Ferrero did not respond to questions about whether the changes to the European recipe were a trial intended to be adopted elsewhere at a later date.

Nutritionist and dietician Dr Rosemary Stanton said the healthiest ingredients – hazelnuts and skim milk powder – made up only 21 per cent of the product.

“The changes to the recipe are slight but you wonder why anyone would increase the sugar content of a product that is already high in sugar,” she said.

Deakin University marketing expert Michael Callaghan said any change to a traditional recipe was a “very dangerous” business move.

He cited Coca-Cola and Vegemite as recent examples where recipe changes had been met with widespread consumer backlash.

“Increasing sugar or fat content is a classic ‘filler’ strategy,” Mr Callaghan said.

“Since demand for Nutella has increased in recent years, you need to buy more ingredients.

“This can squeeze your profits and so, to compensate, you increase the amount of ‘filler’ and might skimp on expensive ingredients like hazelnuts.”

Ferrero eyes Australian hazelnut production

Turkey produces about 70 per cent of the world’s hazelnuts, with Ferrero Australasia importing about 2000 tonnes to meet local demand.

However, Ferrero’s long-term reliance on production in Turkey – and their volatile pricing – has led it to search for new suppliers, including Australia, Canada and Chile, Fairfax reported.

A Rural Industries Research and Development Corporation report estimated hazelnut production in Australia would increase from 170 tonnes up to 3000 tonnes by 2020.

“The Ferrero group is concerned about constancy of supply of fresh hazelnut kernel and the potential impacts this can have on the price of hazelnuts. Presently, approximately 70 per cent of hazelnuts are produced in Turkey,” the report read.

“With the aim of diversifying production regions and securing constant, reliable hazelnut supply, the Ferrero group has identified Australia as a country suitable for hazelnut production.”

But Australia has not been without hazelnut supply problems of its own in recent years.

A craze that emerged in 2015 saw Nutella being used for doughnuts, ice cream and flavoured coffee and increased demand so much that wholesale supplies began struggling to keep up, leading to a temporary Nutella shortage.