How do you keep nut toppings on chocolate bars fresh?

Nuts are a popular and tasty addition to chocolate bars, think crunchy hazelnuts, toasted almonds, pecans or pistachios. They not only provide texture and flavour, but also a more luxurious look. Many chocolate producers therefore like to add them to their chocolate bars.

For the average artisan chocolatier, who distinguishes himself by incorporating refined ingredients into the chocolate, nuts are indispensable part of the assortment. However, there is one major drawback to using nuts as a topping: they quickly lose their crunch.

The problem: oxygen = enemy number one

Nuts are naturally rich in unsaturated fats, making them extremely susceptible to oxidation. When nuts are exposed to oxygen and moisture, they quickly lose their crunch and can develop a bitter taste. But nuts are not the only ones that suffer from air: chocolate itself is also prone to oxidation.

Prolonged exposure to oxygen causes the fats in cocoa butter to slowly oxidise, leading to loss of flavour, dull or whitish discolouration (fat bloom), and a less fresh smell. In addition, aromas from the chocolate may volatilise or be affected by contact with oxygen or other environmental odours.

The role of packaging material

Packaging materials play a crucial role in maintaining freshness. Pay particular attention to the barrier properties of the film or wrap used: Plain aluminium foil offers excellent protection against air and moisture. Pergamines or paper with lower barrier properties are more likely to let oxygen through, affecting shelf life. Wondering whether your current materials have good barrier properties? Contact us and we will be happy to share our knowledge.

Packaging options under the microscope

Sealing with aluminium foil or other materials
Sealing with aluminium foil is often seen as a solution for preserving freshness. However, it may sometimes appear to be airtight when that is not always the case. A lot of aluminium foil is single-sided or not suitable for hermetic seals, meaning it cannot completely block air or moisture.

To achieve truly airtight packaging, it is important to use specific coated barrier films suitable for creating a reliable seal. Here, the quality of the film layer and the perfect adjustment of the sealing machine are essential. Without the right combination of film and machine settings, the sealing process can lead to imperfect seams, which will still allow air and moisture to pass through the packaging.

In smaller productions, sealing is often done manually, for example with a refined curling iron or a hand sealer. This works fine for smaller batches, but requires skill and precision to ensure a good seal that keeps out air and moisture. It is time consuming, and with this method you also run the risk of thermal damage to the bar during the sealing process.

There are also special packaging machines that can seal the inner layer of an aluminium laminate before applying the wrapper to the bar. However, these machines are mainly aimed at hyperindustrial production. These machines are designed for extremely high output (more than 12 million bars per year) and can effectively seal the inner foil of the aluminium laminate. Although these machines are often very efficient, it is important to note that even with these machines, the seal is not always completely hermetic. This means that, despite advanced technology, it is sometimes still possible for small amounts of air or moisture to enter the packaging. However, the purchase price of such machines is very high, and they require considerable space and infrastructure, usually only making them accessible to large producers.

Flowpack packaging
Flowpack is airtight, provided you work with the right laminate (e.g. alu-coated or EVOH barrier) and a properly set machine. This makes it an excellent option for extending the shelf life of nut toppings.

But to be honest: the look of a bare flow pack is anything but premium. It quickly looks like your average supermarket bar: functional, but totally inappropriate for an artisan or bean-to-bar bar. The shiny plastic, the sealing at both ends and the typical "snack size" give your bar the look of a cheap supermarket chocolate, rather than a carefully crafted chocolate experience.

Still want to use flow pack because of shelf life? In that case, always put the flow pack in a cardboard box or sleeve. This is the only way to maintain the technical advantages and give your brand the presentation it deserves.

2-layer folding style
The folding style is a classic and proven packaging option for chocolate bars without sealing the inner layer. The strip is folded tightly into several layers of material, usually a combination of a barrier layer (such as aluminium or laminates) and an outer layer of paper or cardboard. This packaging exudes craft and quality, and fits perfectly with brands aiming for a premium or artisanal image. Compared to a hermetic seal, the folds, the right material with good barrier properties and glue ensure a sealed package. This packaging is less airtight than sealing or flowpack, but still offers excellent barrier properties.

Incidentally, this cardboard outer layer is not reserved for folded inner layers. Flow-packed bars can also be boxed or sleeve-packed on a BTB25 to still achieve a high-quality presentation.

Production tips for maintaining the freshness of nut toppings
Besides the right packaging, there are also some production recommendations that can help you preserve the freshness of nut toppings for longer:

• Coating nuts with sugar or other protective coating: A thin coating can act as a barrier against air and moisture.
• Incorporate nuts ín the chocolate instead of on top: This means they are protected by a layer of chocolate
• Quick turnaround in sales: The shorter the storage time, the lower the chance of quality loss. Fresh is key!

Do you have any questions about maintaining freshness or are you looking for the right packaging solution for your nut toppings?

As you can see, choosing the right material and packaging is essential for maintaining quality. We will be happy to advise you on the best options for your product and production needs. Contact us or share your own tips with us, we would love to hear about your experiences!