Coffee beans are "alive" after roasting. They continue to release carbon dioxide (a process called "outgassing"). If the package is sealed immediately after roasting, it will cause the package to bulge or even burst . Without outgassing, these unpleasant flavors will remain in the beans, ruining the final taste.
Key factors affecting coffee flavor
1. oxygen
Coffee beans are rich in oils and aromatic compounds . These react easily with oxygen, causing oxidative rancidity , which makes the coffee taste bland and stale. Ground coffee is more susceptible to oxidation because it has a larger surface area, which accelerates oxidation.
2. carbon dioxide
Coffee beans produce a lot of carbon dioxide after roasting, and continue to release it in the following weeks. If you don't give these gases a way out, the packaging bag will swell like a balloon or even burst.
Coffee packaging by product form
1. Ground coffee packaging
Because oxygen permeates every particle of ground coffee, it quickly loses its freshness. To protect the ground coffee, manufacturers use vacuum- sealed packaging combined with nitrogen purges to remove oxygen. Ground coffee is often packaged immediately after grinding to lock in the aroma before oxidation occurs.
2. Whole bean coffee packaging
Whole beans retain their flavor longer, but they still need to release CO2. The solution? One-way degassing valve bags . These bags allow CO2 to escape without letting oxygen in, keeping the beans safe and fresh for weeks.
3. Why aren't coffee beans vacuum packed?
Vacuum packaging is great for many foods, but it's not so great for roasting coffee beans. Here's why:
Structural risk : The suction force may crack or crush the beans.
Degassing problem : After roasting, coffee will continue to release carbon dioxide for several days. In a vacuum environment, the carbon dioxide has nowhere to go, causing the packaging to swell or break.
Flavor "suffocation": When coffee releases carbon dioxide, it also removes unpleasant flavors (such as smokiness and astringency) produced during the roasting process. If exhaust is not possible, these unpleasant flavors will remain in the beans, ruining the final taste.
That’s why industry experts, including the Specialty Coffee Association, recommend using valve bags and nitrogen flushing rather than vacuum for roasting coffee beans.
Best Coffee Packaging Schedule
The freshness of coffee changes rapidly after roasting. The general process of change is as follows:
Day 0-2 : The coffee will release a lot of carbon dioxide. Packaging too early will cause the bag to swell.
Days 2-7 : Ideal time to pack whole coffee beans into one-way valve bags.
Day 7 and above : Ground coffee should be nitrogen sealed to prevent oxidation.
Choosing packaging for different stages of coffee
Freshly roasted coffee beans (degassing period) → One-way valve bag allows safe release of carbon dioxide.
- Whole coffee beans ready for sale → Nitrogen flushing helps extend shelf life on store shelves.
- Ground Coffee → Nitrogen-purged Modified Atmosphere Packaging (MAP) provides maximum freshness.
- Bulk Export → Laminated bags with nitrogen and degassing valves protect the coffee during transport.
How to Choose the Right Packaging Bag for Your Coffee
Different coffee products and lifecycle stages require different packaging solutions.
Kraft Paper Coffee Bags
Kraft paper coffee bags typically feature a kraft paper exterior with an aluminum foil interior. This combination of materials provides excellent light and moisture protection, making them ideal for packaging freshly roasted coffee beans during their intense degassing phase.
Pure Aluminum Foil Coffee Bags
Pure aluminum foil coffee bags are typically constructed from a composite structure of aluminum foil (AI), nylon (PA), and polyethylene (PE). These bags offer excellent light and moisture protection, providing the highest level of protection. They also come in a variety of colors and a stylish design. Furthermore, they often feature a double zipper design for maximum gas isolation, making them ideal for finished beans, ready for shelf storage, or for long-term storage.
Coffee Bags with One-Way Valve
Coffee bags with one-way valves are equipped with a key feature: a one-way valve. This small valve not only keeps the coffee beans "active" and smoothly discharges carbon dioxide and bad taste, but also effectively prevents external oxygen from entering the bag and oxidizing the coffee beans, thereby preventing the coffee from losing freshness.
How to choose a suitable coffee packaging machine
Not all machines are built the same. When choosing your equipment, consider:
Valve sealing ability → is crucial for whole bean packaging.
Nitrogen flush system → replaces oxygen with inert gas to keep coffee fresh.
Vacuum sealer → Suitable for other foods, but not for roasting coffee beans.
Customizable Packaging Lines → Adaptable systems allow roasters and manufacturers to select bag size, sealing method, and level of automation.
Related questions and answers
How long do roasted coffee beans stay fresh?
Coffee beans typically stay fresh for 2-4 weeks, but ground coffee only stays fresh for 1-2 weeks.
Do one-way valves really work?
Yes. It blocks oxygen from entering while allowing carbon dioxide to escape.
What gas is best for food packaging?
Nitrogen has a wide range of uses and is very important for food safety
Can vacuum packaging be used for green coffee beans?
Yes. Since green coffee beans don't release carbon dioxide, vacuum packaging is ideal for long-term storage.
Summary
The two biggest factors affecting coffee freshness are oxygen and carbon dioxide . Vacuum sealing may sound effective, but it can damage roasted beans, trap carbon dioxide, and take away flavor. Best practices are:
After baking, package it promptly and correctly .
Use valve bags to package whole coffee beans.
Use nitrogen flushing or modified atmosphere packaging (MAP) for ground coffee and long-term storage .
LTPM CHINA offers professional coffee packaging machines equipped with nitrogen flushing and degassing valve sealing . Whether you are a small roaster or a large manufacturer, we can provide customized solutions to meet your needs.