Fermentation

Fermented Green Coffee Beans

Unroasted fermented green coffee for roasters. Every coffee ferments during processing, but these are lots where the producer has deliberately controlled and extended fermentation – sealed anaerobic tanks, longer times, carbonic maceration, added yeasts or co-fermentation – to build specific flavours. Expect fruit-forward, expressive cups. Buy from 0.5kg with samples on most lots, or step back and compare them with every green coffee we stock. Looking for roasted coffee? These are raw beans you roast yourself – here's how to start.

  • Why fermentation matters in coffee processing

    Once cherry is picked, yeasts and bacteria start breaking down the sugars in the fruit and mucilage. In conventional washed processing that stage is short and mostly about removing mucilage. In the lots here, producers manage it as a flavour step – controlling oxygen, time, temperature and the microbes present – to develop fruit, acidity and body. Our guide to coffee fermentation explains what it means for the green coffee you buy, and our glossary entry has the short version.

  • Types of fermentation in this range

    Anaerobic: sealed, oxygen-free tanks. Extended fermentation: longer than usual, often temperature controlled. Carbonic maceration: whole cherry in a CO₂-filled tank. Yeast inoculation: selected yeast strains added to steer the result. Co-fermentation: fruit or other ingredients fermented with the coffee – see our co-fermented coffee guide and infused range. Lactic fermentation favours lactic acid bacteria for a creamier body.

  • Roasting fermented green coffee

    Treat these as aromatic, sugar-rich lots. Lighter roasts with controlled development keep the fruit vivid; long development turns fermentation notes boozy or ashy. Many fermented lots colour faster than their density suggests, so ease off early heat and follow the rate of rise through first crack. Give them time to rest – fermented lots often open up after several days.

  • Origins in our fermented range

    Colombia leads – producers there pioneered many of these protocols – followed by Peru, Brazil, Mexico and Ecuador. For the economics behind it, read why producers take risks on varietals and processes.

Your questions, answered

Is all coffee fermented?

To some degree, yes – fermentation happens whenever cherry or mucilage sits before drying. 'Fermented' coffees are ones where the producer deliberately controls or extends that stage to shape flavour.

What does fermented coffee taste like?

More complex fruit and acidity than conventional lots: tropical fruit, berries, wine, spice, sometimes yoghurt or rum-like notes. Well-made lots are clean and vivid; poorly controlled ones taste vinegary or funky.

What is co-fermented coffee?

Coffee fermented together with other ingredients – usually fruit, sometimes spices or yeasts from other fermentations – so their compounds influence the coffee. It's debated in specialty, and we always label it. More in our co-fermented coffee guide.

Are fermented coffees good for espresso?

They can make striking single-origin espressos, especially drunk black, but their intensity can dominate a blend or clash with milk. Many roasters use them as a limited release or a filter offering.

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 sizes or quantities can I order?

All our green coffee beans come in 0.5kg, 1kg and 5kg bags. Approved wholesale accounts can also order 10kg and 20kg at lower per-kilo prices, and for full sacks or anything larger, just get in touch – we'll help you put a custom order together.