The 700 chocolate bars that could help save tonnes of packaging

Nov 5, 2015

In a sealed room deep inside a Swiss laboratory, 700 bars of chocolate sit neatly side-by-side, wrapped in transparent packaging, attached to sensors, exposed to light for 24 hours a day.


It might sound like the indoor farm of a chocoholic’s fantasies, but this is not a magic recipe for cultivating ready-made confectionery.

What’s being propagated here is knowledge. Knowledge that could ultimately help save tonnes of packaging every year.

Information gap

Here’s why: some products are more sensitive than others to elements such as moisture, oxygen and light.

Not enough is known about the extent to which these ‘degradation factors’, as scientists refer to them, affect sensitive products over the course of their designated shelf lives.

The lack of precise data available, as well as the methods for gathering it, can lead manufacturers to overestimate the level of protection a product’s packaging needs to provide.

The problem? Generally speaking, the higher the barrier a packaging material offers, the more complicated its structure and the potentially greater its environmental footprint.

The more accurately you can predict a product’s sensitivity over a specific period of time, the more easily you can identify optimal packaging materials that will still keep it fresh.

Critical point

“There’s almost no such thing as a perfect barrier when it comes to packaging,” says Robert Witik, the scientist leading the study at the Nestlé Research Center in Lausanne.


“People may think no oxygen gets through plastic, for example, but different types of plastic are actually permeable to different degrees.

"One of our goals here is to identify the critical point at which the amount of oxygen a product consumes begins to have an impact on its taste and quality."

In other words, how much oxygen does the chocolate bar need to react with before it goes off?

Test groups

Before they could begin their tests, Robert’s team had the painstaking task of wrapping each of the 700 individual chocolate bars in different packaging materials with varying properties.

“We’ve divided the bars into groups and packed them under different storage conditions,” he explains.

“Some are wrapped in packaging with a high oxygen barrier, while others are wrapped in packaging with a low oxygen barrier.

“We’ve also adjusted the level of oxygen inside the packaging, so some bars have more oxygen between chocolate and wrapper than others.”

Accelerated situation

What doesn’t vary in this experiment is the light, which the chocolate is exposed to continuously, and at the same intensity.

“In normal circumstances the product would never be subjected to this much brightness,” says Robert. “This is an accelerated situation.”

To discover exactly how much light the chocolate would see in reality, the team is conducting a parallel study that simulates its journey through the supply chain.

They’ve taken another set of bars, packed them in same conditions, and are moving them from periods of dark to light to dark again, mimicking their passage from warehouse, to shop, to kitchen cupboard.

Data driven

Back to the first lab, where over the next few months the scientists will be measuring the amount of oxygen the bars consume, using delicate sensors attached to chocolate from the different test groups.


Every 30 days, they send a handful of bars from each group for another type of test: this time with sensory experts, to see if there has been any loss of quality and taste.

In the long-run, their findings should enable the company to calculate how much oxygen chocolate will consume when packed in a given material under specific conditions.

But the research is not only about chocolate. This is just the start. Robert and the team are already studying other products to establish a methodology that could be applied to Nestlé’s entire portfolio.

Their aim is to feed all the information they collect into a ‘shelf-life prediction tool’ they’re developing to help packaging engineers across the company to make more informed decisions about the packaging they select.

“Packaging materials can be very complex, with many layers performing different functions,” says Robert. “So choosing the right material is a very technical process.

“We want to help our engineers take a more data driven approach to what’s known as packaging ‘optimisation’ - better matching the performance of packaging with a product’s actual protection requirements.”

Challenging convention

Providing packaging engineers with an improved means of selecting material to ensure a product’s quality and safety over a particular shelf life is one aspect of this research.

Challenging conventional wisdom is another.

The scientists are also trying to encourage product managers to question the duration of the shelf life they’ve assigned to a particular product in the first place.

Why? Let’s say a product is given a shelf life of 24 months, but in reality people consume it within nine.

The chances are it’s being ‘over packed’ in an unnecessarily high level of protection.

Shortening its shelf life, and adjusting its associated packaging requirements, can be a simple but highly effective way of improving its environmental performance.

Public pledge

It’s a lesson Nestlé has learnt thanks to a recent pilot project in the Philippines.

Using information they already had on how moisture affects powdered beverages and coffee mixes, its researchers re-examined the shelf lives accorded to some of these products.

By tailoring the shelf lives, and so revising the packaging specifications that went with them, the company has managed to reduce the amount of packaging used by 1,500 tonnes annually.

Click to learn about our commitment to improve the environmental performance of our packaging

All of this work contributes to Nestlé’s public commitment to improve the environmental performance of its packaging, with a pledge to avoid the use of at least 100,000 tonnes by 2017, while guaranteeing the safety and quality of its products.

Future proof

Although at first glance, wrapping up 700 chocolate bars and leaving them on a shelf for months may not appear to be contributing to this target, the long-term gain is clear.

The closer Nestlé can get to predicting exactly how certain products will react to different conditions, the less packaging those products will require.

So while scientists may not have a formula for growing your own confectionery, they might have found a way to ensure some of your favourite products are more sustainable in future.

It’s hard to imagine even the most dedicated of chocolate lovers being disappointed by that.

Related links
Our commitment: Improve the environmental performance of our packaging
Our commitment: Improve resource efficiency in our operations
Our commitment: Assess and optimise the environmental impact of our products

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