Coffee is one of the few products that can be consumed safely long after it is harvested and roasted.
It is during the roast that coffee develops its delectable atoms and unique flavour notes and the process makes the beans extractable. That said, as soon as coffee is roasted, the steady decline of freshness begins almost immediately.
Over the following days and weeks, internal changes in the coffee continue to take place as carbon dioxide (CO2) is released, and several chemical reactions that began during roasting cause the coffee to break down and become stale.
For specialty coffee roasters, it’s important to ensure that the freshness of their coffee is preserved right up until the moment of consumption. This means it must be protected from light, oxygen, moisture, and heat – all of which can adversely affect the quality, flavour, and aroma of the beans.
There are many ways to preserve freshness in coffee. One method that is somewhat controversial within the specialty industry is the use of vacuum sealers.
Vacuum sealers remove all the oxygen from a coffee bag once the beans are placed inside. The bag is then immediately sealed to prevent any oxygen from re-entering.
Notably, some believe vacuum sealing can have interesting effects on the beans, which begs the question of whether roasters should invest in vacuum sealers.
What is coffee freshness and how is it lost?
Roast coffee is considered fresh when the original, unimpaired characteristics and qualities can still be tasted.
Therefore, preserving these qualities and guaranteeing a fresh product is a priority among coffee roasters who want to meet the expectations of their customers.
Over time, roast coffee gradually loses its complex flavours and aromas, eventually becoming flat, bland, and stale.
This is because, during the roast, coffee is exposed to many external factors that alter the physical and chemical structure of the beans.
Once coffee is roasted, it must degas to allow the release of the carbon dioxide (CO2) trapped within the beans. For specialty coffee roasters, degassing is vital: it ensures that the coffee will be fresh, aromatic, and balanced as intended by the time it reaches the consumer.
This is because the release of CO2 during various stages, from roasting to consumption, is inextricably linked to the characteristics and properties of coffee.
According to a study published in the 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.
Additionally, elements such as light, oxygen, moisture, and heat are key factors that contribute to the deterioration of coffee freshness.
Therefore, roasters must ensure their packaging not only preserves coffee freshness but also protects the beans from exposure to these elements.
What is vacuum sealing and how it can help preserve coffee freshness?
As a product, packaging is designed to protect its contents from any external factors that may compromise its integrity.
Vacuum sealing is commonly used to store dry foods, such as meats, fish, and coffee for a long period of time.
Vacuum sealing reduces atmospheric oxygen, limits the growth of aerobic bacteria, and prevents the evaporation of volatile components.
Vacuum sealing is an effective way of prolonging the shelf life of coffee because it is completely airtight, helping reduce the chances of contamination occurring during storage, transfer, and handling.
As well as being hygienic, the absence of air around the contents means it takes up minimal space when stored or transported.
Isolating the coffee beans reduces their exposure to oxygen, prolonging the original attributes of the coffee for longer.
However, one important factor must be considered when deciding whether to use vacuum sealers: carbon dioxide.
As previously mentioned, coffee beans release CO2 once roasted and will continue to do so after they have been vacuum sealed.
Due to the lack of space within a vacuum-sealed package, the build-up of CO2 may cause the coffee bag to burst at the seams.
If the coffee bag does not pop, the CO2 trapped inside may lead to an accumulation of moisture. This, in turn, exposes the beans to higher humidity levels and may affect the delicate taste profile or lead to the growth of bacteria.
As a result, vacuum-sealed coffee bags often include a degassing valve to prevent CO2 from building up and causing it to rupture.
A degassing valve is a one-way vent that allows CO2 to escape without letting oxygen enter. In the absence of a degassing valve, the roasted coffee needs between 24 and 48 hours to degas before it’s vacuum sealed.
Should roasters invest in vacuum sealers?
Maintaining freshness over time is a key element to guaranteeing a high-quality coffee experience for consumers.
Deciding which sealing method is best will often depend on a roaster’s finances, location, and demand for the product.
Vacuum sealers have several pros and cons that roasters should consider before making an investment.
One of the major advantages of vacuum sealers is the beans reduced exposure to oxygen – which can have negative effects on the flavour and freshness of the coffee.
Additionally, the method helps prolong the life of the coffee and retain its original flavour characteristics.
While vacuum sealing is relatively cost-effective and easy to implement, it may be a labour-intensive method for roasters catering to large amounts of orders.
Roasters have several options when it comes to sealing their coffee packaging.
For instance, another incredibly popular and successful method is nitrogen flushing. This involves “flushing” the oxygen from the packaging using nitrogen gas.
Unlike oxygen, nitrogen does not react with foods, nor does it affect flavour or texture. However, it is heavier than oxygen and provides a “cushion” for the contents of the packaging during transportation and storage.
Another option is heat sealing, which uses wires that are triggered when a heat-resistant bar is pressed on the opening of a coffee pouch or bag. When the bar is closed, an electrical current heats up the wires using electric light.
These wires heat up almost instantly and melt the package’s material while the bar presses the two sides together, effectively sealing it. Sealing packages keeps the coffee in a sterile and impenetrable environment until consumption.
As a specialty coffee roaster, it is crucial that all the hard work and effort that goes into creating quality coffee is not affected by poor packaging decisions.
At MTPak Coffee, we can help you decide on the best resealing option for your coffee bags. We offer quality heat sealers and additional resealable solutions that will keep your specialty coffee protected from external factors and prolong its shelf life.
From heat sealers and loop zippers to tear notches and zip locks, all our resealable features can be integrated into our recyclable, compostable, and biodegradable coffee bags.
We offer a range of 100% recyclable coffee packaging options made from renewable materials such as kraft paper, rice paper, or multilayer LDPE packaging with an environmentally friendly PLA lining.
We also offer low minimum order quantities (MOQs) to micro-roasters who are looking to remain agile while showcasing brand identity and a commitment to the environment.