How odor from packaging can become a real problem

Roasted coffee has a very rich system of volatile compounds, and those compounds are largely responsible for how we perceive its aroma. So unsuitable packaging doesn't just change how well the product stores — under certain conditions, it can actually introduce an unwanted odor.

Two phenomena need to be distinguished. One is coffee losing the aroma compounds it originally had. The other is the product picking up an additional odor from the environment or the contact material. When both happen at once, a drinker can perceive a product very different from what it was right after packing.

Food packaging is treated as a food-contact material, and its components need to be assessed against their intended use. The FDA notes that food-contact substances include packaging and its components. That shows choosing a bag isn't just about shape or thickness.

For coffee, the important question is whether the material suits the product, the contact conditions, and the intended storage period.

Why coffee readily reveals unwanted odors

Coffee has a strong capacity to hold and release aroma compounds. After roasting, the bean's surface — and especially ground coffee — has a much larger contact area, which makes interaction between the product and its environment more noticeable.

If the packaging material, adhesive layer, ink, coating, or other components contain volatile compounds, those substances can create an odor within the bag's headspace. How noticeable this is depends on the type of material, temperature, exposure time, and the coffee's own characteristics.

It shouldn't be assumed that any plastic-like smell automatically means the material is “toxic.” Sensory odor and safety assessment are two separate questions. A material might have a smell that affects sensory perception while still needing to be separately evaluated for its suitability in food contact; conversely, a material with no noticeable smell isn't automatically considered suitable either.

So controlling odor needs to start with choosing the right material and testing it under actual use conditions.

Factors that increase the risk of odor transfer

High temperature typically speeds up diffusion and the release of many volatile compounds. Longer contact time also increases the chance for substances from the material and the product to interact. Packaging structures with different gas-barrier properties create different conditions too.

Ground coffee is usually more sensitive to its environment than whole beans, due to its larger surface area. If the product is packed in strongly scented packaging right after roasting or grinding, the headspace inside can become a place where volatile compounds accumulate.

Warehouse conditions matter as well. Well-designed packaging stored somewhere hot, with strong chemical smells, or exposed to a strong odor source can still run into problems. Packaging isn't an absolute wall separating the product from everything outside.

So assessing odor needs to consider the material, the product, temperature, time, and the storage environment all together.

Odor control should start before packing

A sound process can begin with choosing a material that's approved for the type of food and the intended conditions of use. The FDA provides food categories and conditions of use for assessing food-contact substances — a reminder that the same material shouldn't be considered suitable for every purpose just because it's commonly used in the market.

After that, a facility can carry out sensory evaluation of the packaging and the product under expected storage conditions. If there's an unusual smell, it's worth identifying whether the source is the coffee itself, the packaging, the warehouse area, or another step in the process.

A simple test at the moment of packing doesn't substitute for a stability assessment over time. Odor can change as temperature, time, and the product's state shift.

Good packaging, then, doesn't just keep coffee contained inside a bag. It needs to help the product retain its original sensory character and avoid introducing a new problem over the entire intended period of use.

References

• FDA — Food Packaging & Other Substances that Come in Contact with Food — https://www.fda.gov/food/food-ingredients-packaging/food-packaging-other-substances-come-contact-food-information
• FDA — Food Types & Conditions of Use for Food Contact Substances — https://www.fda.gov/food/packaging-food-contact-substances-fcs/food-types-conditions-use-food-contact-substances