Extended fermentation

Extended fermentation

Extended fermentation is a high-risk processing method that pushes the boundaries of flavour development. Careful control of temperature, humidity, and oxygen slows fermentation, but the longer the beans ferment, the greater the risk of unwanted flavours. When executed successfully, this method produces distinctive coffees with bold, layered profiles that stand apart from traditional processing

  • Rancho Morelia
    Mexico

    Rancho Morelia

    Rancho Morelia

    Cupping Score
    86.0
    Processing method
    Extended Fermentation
    Varietal
    Bourbon , Typica , Catimor
    Main flavour notes
    Chocolate | Vanilla | Cinnamon
    0kg left
    Out of Stock
  • Sitio Maranhão - Experimental Brazil
    Brazil

    Sitio Maranhão - Experimental Brazil

    Sitio Maranhão - Experimental Brazil

    Cupping Score
    86.25
    Processing method
    Experimental
    Varietal
    Yellow Catuai
    Main flavour notes
    Hazelnut | Brown Sugar | Green Apple
    91kg left
    In Stock
  • Andres Bazos coffee processing
    Peru

    Andres Bazos - Red Caturra - ⚠️ Parchment Issue

    Andres Bazos - Red Caturra - ⚠️ Parchment Issue

    Cupping Score
    83.5
    Processing method
    Washed
    Varietal
    Red Caturra
    Main flavour notes
    Orange Citrus | Caramel | Milk Chocolate
    0kg left
    Out of Stock
  • Explorer - Rolling Green Bean Subscription
    Multiple

    Explorer - Rolling Green Bean Subscription

    Explorer - Rolling Green Bean Subscription

    Processing method
    Multiple
    Varietal
    Multiple
    Main flavour notes
    Varies from each coffee
  • Sucalfru 72h Yeast Fermentation
    Brazil

    Sucalfru 72h Yeast Fermentation

    Sucalfru 72h Yeast Fermentation

    Cupping Score
    88.0
    Processing method
    Experimental
    Varietal
    Arara Peaberry
    Main flavour notes
    Tamarind | Starfruit | Watermelon | Juicy
    Preorder
    Available: 25/08/25
  • Auro 72h Yeast Fermentation Acaiá Peaberry
    Brazil

    Auro 72h Yeast Fermentation Acaiá Peaberry

    Auro 72h Yeast Fermentation Acaiá Peaberry

    Cupping Score
    89.5
    Processing method
    Experimental
    Varietal
    Acaiá Peaberry
    Main flavour notes
    Caramel Shards | Yellow Tomato | Physalis | Tartaric | Syrupy
    Preorder
    Available: 25/08/25

Your guide to Extended fermentation

  • What is extended fermentation coffee processing?

    Extended fermentation is a processing method that prolongs the natural fermentation stage in coffee production, allowing for deeper, more complex flavours to develop. Unlike standard washed processing, where fermentation lasts around a day, this method extends the process for significantly longer.

    Producers carefully control factors like temperature, humidity, and oxygen levels to slow fermentation and guide flavour development. While this approach carries risks—such as over-fermentation or unintended flavour changes—when done successfully, it can enhance acidity, sweetness, and overall complexity. After fermentation, the coffee is washed and dried, following the typical steps of washed processing.

  • What are different types of extended fermentation?

    Extended fermentation can take place in different forms, each with its own impact on flavour. For example:

    • Anaerobic fermentation takes place in a sealed, oxygen-free environment, slowing fermentation and producing unique, often fruity or wine-like characteristics.
    • Cold fermentation involves keeping the coffee at lower temperatures—either in refrigeration or through nighttime processing—which slows microbial activity and enhances intricate, layered flavours.
    • Partial drying means drying the coffee cherries partway through fermentation before completing the process. This can intensify complexity and add depth to the cup profile.

  • What are the challenges of extended fermentation?

    Precision is key in extended fermentation, as small changes can dramatically affect the final flavour. The main risks include:

    • Over-fermentation, which can introduce unpleasant vinegary or overly sour notes.
    • Alcoholic flavours that may overpower the coffee’s natural characteristics if fermentation goes too far.
    • Inconsistency, since environmental factors like temperature and humidity can make it difficult to replicate results.

    Because of these risks, producers must closely monitor the process to maintain control. The longer the beans ferment, the higher the risk of unwanted flavours, making extended fermentation one of the most technically demanding processing methods.

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.

How do I find the coffee right coffee for me?

It’s super easy! Just head to our coffee pages and use the search filters to narrow down what you’re after. Whether it’s origin, process, or variety, the filters make it simple to find exactly what you want. You can also check out the main coffee categories through the top menu on our site. Give it a go—it’s straightforward, and if you need help, we’re always here!

Are your coffees ethically and sustainably sourced?

Absolutely! We source all our coffees either directly from producers or through trusted sourcing partners who are just as committed to ethical practices as we are. We take the time to ensure the people behind the coffee are treated fairly. If you want to learn more, you can dive into our values.

Can I cancel my order?

If your order hasn’t shipped yet, just drop us an email at orders@greencoffeecollective.com with your order ID, and we’ll take care of it. If it’s already on its way, we can still help. We’ll just need to arrange a collection. Either way, email us and we’ll sort it out for you. You’re in control!

What sizes or quantities can I order?

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.

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.

What is your process for ensuring consistency between lots or harvests?

We work closely with our sourcing partners to make sure we’re always offering top-quality coffee. Most of the partners you’ll find on our site have years of experience in their regions, and they use that expertise to access the best coffees available each season. Their deep relationships with producers help maintain consistency in both quality and supply.

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.