Anaerobic fermentation

Anaerobic fermentation

Anaerobic fermentation is part of a mini scientific revolution within coffee. This oxygen-free process allows controlled, extended fermentation, enhancing complexity without the risk of over-fermentation. Whether the bean ferments inside the cherry (anaerobic natural) or after removal (anaerobic washed), the result is a coffee with bold, distinctive flavours—often fruity, wine-like, or slightly funky.

  • What is anaerobic fermentation in coffee processing?

    Anaerobic fermentation is an experimental coffee processing method where coffee cherries or beans ferment in a controlled, oxygen-free environment. Producers place them in sealed tanks with one-way valves that prevent oxygen from entering while allowing carbon dioxide, which builds up during fermentation, to escape. This process enables extended fermentation without the risk of undesirable flavours from over-fermentation. The lack of oxygen slows fermentation, allowing the beans to absorb more sugars and compounds from the cherry. This often results in distinctive flavour profiles, with notes that can be intensely fruity, wine-like, or even slightly funky, depending on the process used.

  • What is the difference between anaerobic and aerobic fermentation?

    The main difference is the presence of oxygen. In aerobic fermentation, oxygen is available, which speeds up the breakdown of sugars in the coffee. Anaerobic fermentation happens in an oxygen-free environment, slowing the process and allowing microorganisms to work more gradually. This controlled, slower fermentation can enhance complexity in the coffee’s flavour profile, often creating deeper and more complex flavours compared to traditional fermentation.

  • What is the difference between anaerobic natural fermentation and anaerobic washed fermentation?

    Anaerobic natural fermentation means the coffee bean remains inside the cherry throughout the fermentation process. Since the bean is still surrounded by fruit, it absorbs more sugars and organic compounds, resulting in a coffee with bold, fruit-forward flavours and heightened sweetness. In contrast, anaerobic washed fermentation involves removing the bean from the cherry before fermentation begins. Without the surrounding fruit, the fermentation process produces a cleaner, more structured flavour profile while still benefiting from the unique characteristics of an oxygen-free environment.

Your questions, answered

What is the Green Coffee Collective?

We’re a community of coffee producers and sourcing experts, all working together to make green coffee easy to access—whether you’re a hobby roaster at home or a professional roasting hundreds of tonnes a year. Our platform is designed to simplify buying green coffee, just like any other online shopping experience. No fuss, just great coffee at your fingertips.

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We offer coffee starting from as little as 0.5kg (1 lb) all the way up to full sacks. If you’re looking for larger quantities than what’s listed on our site, just get in touch! We’d be happy to help you organise and place a custom order. We're here to make sure you get exactly what you need.

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If you choose express shipping, your order could arrive in as little as 24 hours (depending on your location). For most orders, if you place it before 12pm, we’ll ship it out the same day! Otherwise, it’ll be dispatched the next day. We aim to get your coffee to you as quickly as possible.

Do you offer support for direct trade relationships with producers?

Yes, we’re always happy to make introductions! If you’re interested in working directly with one of our producers, just send us an email (hello@greencoffeecollective.com) and we’ll gladly help facilitate the connection. For larger volumes, we can also assist with logistics and any complexities involved in sourcing directly from producers.

Do you offer samples or trial batches before committing to larger orders?

Yes, we offer samples for most of our coffees. If you need a larger sample than what’s typically available, we recommend trying one of the smaller quantity options listed on our site. That way, you can test the coffee before committing to a larger order.

How do you handle logistics and shipping for larger orders?

We’ve got you covered! For larger orders, we offer full logistical support, including freight, warehousing, and inventory management. We’ll make sure the process is as smooth and hassle-free as possible, so you can focus on roasting great coffee. If you’re shipping internationally, we can also assist in ensuring smooth delivery.

What is your minimum order quantity (MOQ) for large-scale or long-term contracts?

For larger-scale or long-term contracts, you can start with as little as a single bag. We’re also working on tools to help you access harvests and reserve coffees before they even leave the country. While it’s not fully ready yet, we’re always here to help roasters of any size connect with the producers they want to work with.