A Guide To Preserving The Freshness Of Roasted Coffee

Enrique Moreno
January 21, 2021
zipper on coffee bag

As a specialty coffee roaster, your job is to unlock the unique characteristics of green coffee and provide the best brew possible for consumers. 

However, once your coffee is roasted, it will start to lose its freshness, as various factors cause the flavours and aroma to degrade.

Luckily, there are plenty of measures that roasters can take to preserve the freshness of their coffee and ensure it will taste its best when consumed.

To find out more about the importance of freshness and what roasters can do to preserve it, I spoke with Bartholomew Jones, the founder of Cxffeeblack.

See also: Coffee Roasting: A Guide To Roast Profiles

What Is Freshness In Coffee?

Freshness is highly important for maximising the flavour of specialty coffee, but it remains a somewhat vague and elusive term.

The idea was first coined by Alfred Peet (the founder of Peet’s Coffee & Tea) in the 1960s when he opened a coffee shop in California. His philosophy was that there should be the shortest distance possible between the roaster and the customer, with “freshness” at the heart of his vision.

Since then, the term has evolved and taken on various meanings, with the broadest definition a reference to the “original, unimpaired qualities of coffee”.

A publication by the Specialty Coffee Association (SCA) called The Coffee Freshness Handbook sought – among other things – to add clarity to the discussion. 

Based on a combination of surveys and research, the handbook explores the concept of freshness, and provides practical information on techniques and strategies for preserving and measuring it.

As well as observing the factors that cause coffee to degrade over time, their study measures the impact of coffee freshness on quality from a sensory perspective. Essentially, their aim was to devise a quantitative and qualitative set of measurements for what has always been a largely subjective concept. 

Despite the growing body of research into coffee freshness, there are a number of misconceptions about the topic.

For instance, one is the idea that coffee is at its freshest and, therefore, best consumed, immediately after roasting. While, in principle, it is better to consume coffee as close to the roast date as possible, the beans require time to degas before they reach the “optimum” point for consumption.

Degassing is the process by which carbon dioxide (CO2) and other volatile gases absorbed by the beans during the roasting process are gradually released. CO2 escapes the bean rapidly within the first 24 hours after roasting, then gradually over the course of the next few days. 

Roasted coffee should be left to degas until the concentration of CO2 reaches a level that brings out the best qualities of the beans, typically two to three days after roasting. 

Brewing too soon will likely result in uneven extraction and an imbalanced flavour. It’s for this reason that most specialty roasters will include a “roast date” on their packaging, indicating the exact day on which their coffee was roasted (and ergo giving consumers a window in which to consume it).

An image of coffee being poured into a coffee grinder cofee freshess, roasted coffee, in a A Guide To Preserving The Freshness Of Roasted Coffee

Why Is Freshness Lost?

Although freshness is a fundamental part of maximising flavour when brewing coffee, it can very quickly be lost. 

In Espresso Coffee: The Science of Quality, Andrea Illy and Rinantonio Viani describe the loss of freshness as a “progressive imbalance in the aroma profile”. In other words, this is not only a loss of volatile aroma compounds, but also the formation of new aroma compounds that can cause an imbalanced flavour in the cup.

According to the SCA, the “age-old enemies of freshness” are oxygen, moisture, and temperature. Exposure to any one of these external factors will result in coffee losing its aroma more quickly, and becoming stale and flat-tasting as a result. Oxidation, in particular, can have a devastating effect on the freshness of coffee.

Oxidation happens as a result of the degassing process, where oxygen replaces the CO2 that has escaped and causes the compounds in the coffee to change. Research suggests that for every 1% increase in the oxygen levels in coffee, there is a 10% increase in the rate of degradation.

For specialty roasters, it’s also important to consider whether they will be predominantly supplying ground or whole bean coffee as this can have a dramatic impact on the rate of degassing.

When coffee is ground, the surface area increases, causing a quicker release of CO2, and hence a quicker process of oxidation. According to Java Presse, for ground coffee it takes just 30 minutes to reach the point where freshness noticeably declines. It’s for this reason that baristas tend to grind only small batches of coffee at any one time. 

When coffee loses its freshness, it tends to taste flat, bland, and woody, masking any distinct characteristics it may have had. In an article for USA Today, the CEO of Merchants of Green Coffee, Derek Zavislake, says: “Coffee is like a fine wine. It gets its flavour from its region, but you’re only going to be able to taste it if the coffee beans are fresh.”

An image of a degassing valve for preserving coffee freshness, in a A Guide To Preserving The Freshness Of Roasted Coffee

How Can Packaging Preserve Freshness?

Hours of hard work and effort can be undone if the freshness of coffee hasn’t been effectively preserved by the time it reaches the consumer. 

For that reason, it’s crucial for specialty coffee roasters to do everything they can to preserve the freshness of their coffee. This involves choosing coffee packaging that will prevent exposure to any factors that will have a negative impact on quality.

Bartholomew Jones is the founder of Cxffeeblack, a social enterprise that seeks to reclaim the black history of coffee. He tells me that as well as protecting their coffee from oxygen, temperature, and moisture, they try to limit exposure to light.

“At Cxffeeblack, we use all-black packaging because it minimises light transfer,” he says. “But as long as it’s double-layered, I think it will be effective.”

Indeed, multilayered packaging is significantly more reliable at preventing coffee from losing its freshness than single layered. This typically involves an aluminium foil lining with a bioplastic or kraft paper exterior. 

However, recent concerns over the recyclability of these coffee bags have led many roasters to choose more sustainable options. These include plant-based materials with polylactic acid (PLA) laminates, which limits environmental damage while serving a similar purpose to aluminium foil.

In addition to multilayered packaging, Bartholomew also recommends adding components to your coffee bags that extend the freshness of your coffee both on the shelf and at home.

“A degassing valve is vital for allowing coffee to release CO2 without letting oxygen in,” he says. “The packaging should also be resealable, so that you can keep the coffee airtight after it’s been opened.”

A degassing valve is a one-way vent that can be fitted to coffee packaging either before or after manufacture. Without them, the coffee would either go stale due to exposure to oxygen or result in burst packaging due to built up CO2.

The resealable packaging he describes usually comes in the form of a zipper that can be used to access the coffee and prevent oxygen from entering the bag. 

It’s vital for specialty roasters to do everything they can to preserve freshness, whether for whole bean or ground coffee. Not only is it essential in maintaining quality, it will ensure consumers are able to get the best results every time they consume it. 

At MTPak Coffee, we offer a range of sustainable packaging solutions that will effectively preserve the freshness of your coffee. From multilayered pouches to degassing valves and resealable zippers, we can help you find the best option for your coffee.

For information on our coffee packaging solutions, contact our team.

MTPak Coffee

Photo credits: MTPak Coffee

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