How resealable coffee bags help to reduce waste

According to the Food and Agricultural Organization (FAO), around one-third of the world’s food is lost as waste, mainly at retail and consumer levels. This food waste accounts for as much as 10% of global greenhouse gas emissions.

This figure also includes wasted coffee – whether it’s thrown out because it’s stale or begins to take on mould. Several factors can cause roasted coffee to turn stale, including oxidation, excess humidity, and even intense sunlight. This causes the volatile aroma and flavour compounds of the coffee to deteriorate. However, high-quality resealable coffee bags can reduce this waste.

To learn more about the importance of resealable coffee bags, I spoke with Dr. Laura Richard, co-founder of Saltwinds Coffee Company. She has a PhD in Chemistry and years of experience in consumer packaged goods research at Procter & Gamble.

How can the environment affect the flavour profile of roasted coffee?

As soon as coffee is roasted, it becomes volatile and therefore susceptible to degradation. Over time, it will gradually lose all of its volatile flavour and aroma compounds, which will be replaced with oxygen – a process known as staling. The key factors that accelerate this process include temperature, humidity, and moisture content. These irrevocably alter its flavour and final cup profile, making resealable coffee bags crucial.

Laura explains how she has seen the environment and storage affect both green and roasted coffee at Saltwinds. Living on the Canadian shores of the Atlantic, Laura and her co-founder Brad Rideout were inspired by how coffee used to taste when it first travelled overseas from origin a few hundred years ago.

“We grew up hearing stories about how coffee used to taste better when it came in on the wooden sailing ships, and that nowadays the coffee coming in on the big metal container ships just doesn’t taste the same. In the days of sail, during the long journey from tropical ports, it makes sense that ocean air exposure would transform the coffee,” Laura recounts.

Saltwinds’ ocean air infusion process recreates that historic coffee taste, which imparts a smoother, less bitter, and more aromatic flavour profile.

“Consumers tell us they love the rich aroma when they open a bag of Saltwinds, so we’ve done a lot of work to find packaging that captures that freshness for them,” Laura explains. Roasters who tediously perfect their coffee profiles need reliable resealable coffee bags that preserve their hard work.

Why does roasted coffee require such careful preservation?

The chemical composition of a coffee bean changes when it is roasted. It becomes brittle and porous, and as such, is more sensitive to external factors. As previously mentioned, exposure to sunlight, oxygen, and heat increases the rate of oxidative degradation, which leads to coffee tasting stale and flat.

This process causes oils, proteins, and other compounds in coffee beans to produce off flavours which make it taste “musty, baggy, stale, [and] papery,” Laura says.

Oxidation is exponentially more problematic with preground coffee, too. “When you grind coffee, the surface area available for oxidation reactions increases by a thousandfold, and degradation accelerates rapidly,” Laura explains.

To combat the degradation caused by oxidation and environmental factors, roasters should invest in high-quality resealable coffee bags that create an airtight seal, maintaining those subtle, delicate flavour notes.

“When we put coffee beans into a bag, there is some amount of oxygen naturally present in the air that is going to stay in that bag too, and encourage those oxidative degradation reactions,” Laura says. “We can, to some extent, control these changes by controlling the environment that the coffee is kept in.”

How do resealable coffee bags protect the flavours of coffee?

Roasters have a few tools at their disposal to preserve coffee quality. First, they can package their coffee as soon as possible after roasting into resealable coffee bags. For example, Saltwinds packages most of theirs within a day of roasting. Second, they can remove as much oxygen as possible from the bags before sealing them. Laura does this by flushing the resealable coffee bags with nitrogen.

“Typically roasters will push oxygen out of the bag by injecting nitrogen air in just before sealing (thus displacing the air), or will apply a vacuum as they seal to suck all gasses out of the bag,” Laura explains.

“It’s important to note that neither technique leads to a completely oxygen free environment – estimates I’ve seen, and data from our own operations, suggests these methods get the oxygen down to 3-5% or so (versus the 21% oxygen in our normal air).”

Finally, roasters can use resealable coffee bags that are easy to close firmly by customers after opening, preferably with a resealable zipper and one-way degassing valve. These valves allow carbon dioxide to leave the resealable coffee bags, but prevent oxygen from entering.

“What we should be looking for is packaging that will allow gasses to escape, but no new gasses to enter,” Laura advises.

High-quality resealable coffee bags are vital because roasted coffee remains in the hands of the consumer for the majority of its shelf life.

“We can take all these different steps to assure quality at the roastery, but we also have to consider what the end consumer will do. They are going to open that bag right up, let air in, and the oxidation is going to speed up again. Depending on how savvy the consumer is, that bag of coffee you worked so hard to protect can get real stale, real fast,” Laura says.

With that in mind, do resealable coffee bags really help to reduce waste? From a roaster’s perspective, absolutely. They prevent coffee from going stale across the production line, ensuring the best possible cup.

“If the consumer doesn’t enjoy their package right to [the] end, if their taste experience degrades and they don’t enjoy the last few stale cups, are they going to blame themselves and their storage method, or will that leave them with a negative impression about the coffee they purchased? I’d rather not take the risk, and also I’d like our consumers to enjoy every bit of the coffee in the bags they purchase from us,” Laura says.

MTPak offers multiple options for resealable coffee bags including zippers, tear notches, and laser scoring. These resealable coffee bags can reduce waste from stale coffee as well as from packaging, as we offer a range of compostable and recyclable materials.