Preserving Coffee Freshness: Degassing Valves & Resealable Zippers

TJ Grant
February 3, 2021
coffee packaging with degassing valve and resealable zipper

For specialty coffee roasters, preserving freshness is vital to maintaining the distinct flavours and aromas of their coffee before it reaches the consumer.

However, after roasting, coffee will immediately begin losing its freshness due to external factors such as oxygen, light, and moisture. 

Thankfully, when it comes to packaging, there are a number of options available to roasters to prevent exposure to these external factors. Two of the most common are degassing valves and resealable zippers. 

To find out more about preserving freshness and how these innovative packaging components can help, I spoke with WBC-certified judge and MTPak Coffee Ambassador Danilo Lodi.

See also: A Guide To Preserving The Freshness Of Roasted Coffee

preserving coffee freshness

Why Is It Important To Preserve The Freshness Of Coffee?

Although a somewhat vague and elusive term, freshness is generally used to refer to the original, unimpaired qualities of coffee. 

At every stage of its life cycle, from production to roasting, coffee picks up distinct characteristics that influence its flavours and aromas. However, when coffee is exposed to factors such as oxygen, moisture, or light, it starts to lose these qualities and become stale, flat, and bland.

“Coffee is like a fine wine,” says Derek Zavislake, CEO of Merchants of Green Coffee in an interview for USA Today. “It gets its flavour from its region, but you’re only going to be able to taste it if the coffee beans are fresh.”

Therefore, for specialty coffee roasters it’s essential to do everything they can to ensure that these qualities have been preserved right up until the coffee is brewed. Not only will it ensure your coffee is being enjoyed at its best, it will also increase the chances of customers returning for more.

According to a 2019 National Coffee Day survey, more than 50% of consumers value freshness more than anything when it comes to choosing coffee beans, ahead of taste profile and caffeine levels.

degassing valve

Preserving Freshness With Degassing Valves

One of the main reasons coffee loses its freshness is the replacement of carbon dioxide (CO2) with oxygen. 

According to a study published in Journal of Agricultural and Food Chemistry, CO2 is a major indicator of freshness, plays an important role in shelf life and in packaging, affects extraction when brewed, and may even affect the sensory profile of a coffee.

CO2 builds up in coffee beans during roasting, causing the beans to increase by 40- 60% in size. In the days that follow, this CO2 is gradually released, reaching an optimal level after a few days. However, if the roasted coffee is exposed to oxygen during this time, it will replace the CO2 and affect the compounds in the coffee, resulting in a loss of freshness.

A degassing valve is a one-way vent that allows the CO2 to escape the bag without letting oxygen in. The valves work when pressure from inside the packaging lifts the seal, allowing CO2 to escape; but when oxygen attempts to enter through the valve, the seal creates a barrier against the inlet.

They are usually included on the inside of coffee packaging with small holes on the outside to allow the CO2 to seep out. This provides an aesthetic look that can also be used to smell the aroma of the coffee prior to purchase.

If roasters expect their coffee to be consumed within a week of roasting, then a degassing valve may not be necessary on packaging. However, unless distributing small quantities of coffee, such as samples, a degassing valve is recommended.

“Without a degassing valve, the flavours of the coffee become stale or take on a strong metallic taste,” Danilo explains. Danilo works as a roaster and coffee consultant, and has been a World Barista Championship-certified judge since 2010. Seven years ago, he was made a representative of World Coffee Events.

resealable zipper

Preserving Freshness With Resealable Zippers

Resealable zippers on coffee pouches are a simple yet effective way of preserving freshness and providing convenience to customers.

In a recent consumer survey on flexible packaging, 10% of respondents said they believed a resealable option was “absolutely essential”, while a third stated it was “extremely important”.

Found on a range of coffee packaging, particularly stand-up pouches, a resealable zipper is a protruding piece of material that fits into a track on the opposite side of packaging. Interlocking plastic pieces snap into place and create friction to prevent the zipper from opening.

They help to extend the shelf life of coffee by preventing exposure to oxygen and keeping the container airtight once opened. Zippers are user-friendly and reduce the risk of spillage, adding value to the overall product for consumers.

However, Danilo tells me that resealable packaging is not solely for the benefit of customers.

“Inside a roastery, there’s a lot of waste bags used for internal tests and consumption,” he says. “A resealable bag means that we can continually use it and reduce waste.”

As people become increasingly aware of the environmental impact of their purchasing habits, it’s important for specialty coffee roasters to take measures to reduce their waste wherever they can. Using pouches with resealable zippers is an effective and inexpensive way of doing this.

“Most end-consumers don’t have the tools to store coffee,” Danilo explains. “The appeal of resealable packaging is that it’s convenient and less waste is created in the supply chain.”

preserving coffee freshness

Ultimately, if you want to preserve your coffee’s freshness for as long as possible, and present a range of benefits to the end consumer, then including both a degassing valve and a resealable option in your packaging is essential.

While the degassing valves maintain the sensory properties and the integrity of your coffee, resealable zippers can minimise extra packaging solutions and showcase your sustainable efforts to your customers.

While most coffee packaging valves contain three layers, MTPak Coffee’s BPA-free degassing valves consist of a cap, an elastic disc, a viscous layer, a polyethylene plate, and a paper filter to provide extra protection against oxidation. Our valves are fully recyclable, helping communicate your commitment to sustainability.

MTPak Coffee also offers ziplocks, along with velcro zippers, tin ties and tear notches, providing you with a range of options for keeping your coffee fresh. Velcro zippers offer audible confirmation of secure closure, while tear notches reassure your customers that your packaging is tamper-free and fresh as possible. Tin ties may work best with our flat bottom pouches to retain structure of the packaging.

For more information on specialty coffee packaging, contact our team here.

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