Don’t mess with pesto! Makers bulk out classic sauce with… bamboo

IT’S meant to be a simple mix of basil, pine nuts, parmesan and olive oil. But the pesto in your cupboard could have an added ingredient – bamboo.

Manufacturers eager to cut costs, and battling a shortage of pine nuts and olives, are adding a range of unusual thickeners to the classic Italian sauce.

Worse still, it is producers in Italy that are guilty of butchering the recipe, according to consumer group Which?.

A test of 12 own-brand standard and premium pestos made in the country found a range of additional ingredients. All standard pestos were made with between 42% and 49% basil, but also contained cheaper alternatives such as cashew nuts instead of pine nuts or a mixture of the two.

Olive oil was replaced with sunflower oil, and parmesan with less expensive Grana Padano and Pecorino Romano cheeses. And all of the standard pestos bar one used thickeners such as nut flour and even bamboo fibres.

It might be assumed that premium pestos – which are labelled ‘alla Genovese’, relating to the sauce’s origins in Genoa – would be true to the traditional recipe, but this was not the case. All had generous amounts of basil as well as extra-virgin olive oil, parmesan and pine nuts.

The British consumer watchdog said its investigation showed that a higher price did not necessarily mean that the product would be free of unwanted ingredients and urged shoppers to check the labelling.

Which? director of research Nikki Stopford said: ‘Pesto has become a staple food in the UK but our research shows that many shoppers may be getting more than they bargain for when it comes to the pesto they are buying – and not necessarily in a good way. Our advice is not to assume that all pesto contains the same traditional ingredients. Check the ingredients list if authenticity is important to you, or if you are trying to avoid certain contents, such as added sugar.’

The sauce was created in Genoa in the mid-19th century, but has predecessors that can trace their roots back to the Roman empire.

It has seen a surge in popularity in recent years, but this spike has coincided with an increase in the cost of ingredients – after Italian pine nut trees fell victim to infestations of parasites, and olive harvests were hit by weather extremes.