The Fermentation Project Kit — 4 × 100g Collector's Cans

⚠️ Important notice: All kits will be roasted and shipped from early September 2026 onwards. This is intentional — we want the coffee to be properly rested before the global cupping event, and to ensure it arrives in perfect condition to customers worldwide. Thank you for your patience.

🎁 Want the full SOLO Brewing fermentation experience?

We've brought together this kit alongside our most iconic fermented releases — Cherry Bomb, Hop Hour, and Metacafeína — into one unmissable limited bundle.

⚠️ Strictly limited. Only 60 bundles available worldwide.

→ GET THE FULL FERMENTATION PROJECT BUNDLE ←

The Fermentation Project — by James Hoffmann

When James Hoffmann announced The Fermentation Project, we didn't hesitate for a second.

The Fermentation Project is a global initiative created by James Hoffmann — one of the most respected voices in specialty coffee — to explore, document, and celebrate the science of fermentation in coffee processing. The project brings together roasters from around the world, all working with the same sourced coffees, to participate in a global cupping event on 3rd October 2026. The goal: to understand how roasting approach, geography, and preparation affect the same fermented lots — and to share those findings with the wider coffee community.

All four coffees in this kit are sourced directly through The Fermentation Project. James Hoffmann and his team selected and curated these lots to represent four distinct points on the fermentation spectrum — from a classic washed to the most extreme end of controlled fermentation science.

🎥 Watch James Hoffmann introduce The Fermentation Project →

Learn more at thefermentationproject.com.

Why We Jumped at This

At SOLO Brewing, fermentation has never been a gimmick. Since we first lit the roaster in Lisbon, we have been obsessed with processed coffees — the ones that push boundaries, that carry the fingerprint of a producer's obsession, that taste like nothing else in the cup. You may already know our fermented releases: HOP HOUR, co-fermented with IPA yeast, CHERRY BOMB, born from five days of red cherry co-fermentation at El Vergel Estate in Colombia, and METACAFEÍNA — Castillo 720 by Diego Bermudez, fermented 720 hours with lactobacillus and finished with thermal shock — one of the most extreme and celebrated fermented coffees in the world.

When James Hoffmann built a project around exactly this philosophy and invited roasters who share this passion to participate, it felt like a natural home for us. We are proud to be part of it — and even prouder to bring it to you.

The Four Coffees — A Study in Fermentation

Each of the four lots in this kit represents a distinct approach to fermentation — designed to be tasted side by side, and to answer a single question: what does fermentation actually do to coffee?

☕ 01 — Washed · The Baseline

A classically processed washed coffee — clean, transparent, and free of fermentation influence. The reference point against which every other coffee in this kit is measured.

Process: Fully washed · Character: Clean, bright, terroir-driven

✨ Love clean, terroir-driven washed coffees? Try Geisha AB — Leon Christianakys — a pristine washed Geisha that lets the variety and origin speak without interference.

🌿 02 — Wild Yeast Fermentation · Spontaneous & Unpredictable

Fermented with naturally occurring wild yeasts — no inoculation, no control. Just the coffee, the climate, and whatever is in the air. Complex, sometimes funky, always alive.

Process: Wild yeast fermentation · Character: Complex, expressive, spontaneous

🍯 Drawn to naturally fermented coffees? Explore Geisha do Brasil — Danilo Barbosa — a honey processed Geisha where natural fermentation shapes every layer of sweetness and complexity.

🧫 03 — Controlled Yeast Fermentation · Precision & Intention

Inoculated with a selected, controlled yeast strain — the same approach used in winemaking and craft brewing. Consistent, layered, and designed to amplify specific flavour compounds in the coffee.

Process: Controlled yeast inoculation · Character: Structured, fruit-forward, intentional

🍺 Fascinated by controlled fermentation? Meet HOP HOUR — Brasil, Catuai Amarelo by Danilo Barbosa — co-fermented with IPA yeast for 36 hours, delivering tropical fruit and hop-forward citrus in every cup.

🧪 04 — Lactobacillus Fermentation · Science at the Extreme

Fermented with lactobacillus — the same bacteria behind yoghurt, kimchi, and sourdough. Lactic acid fermentation that transforms the coffee's acidity, texture, and depth in ways that challenge every expectation of what coffee can taste like.

Process: Lactobacillus inoculation · Character: Bright acidity, deep complexity, extraordinary texture

🔬 Already obsessed with lactobacillus fermentation? Meet METACAFEÍNA — Castillo 720 by Diego Bermudez — fermented for 720 hours, finished with thermal shock, and used by a World Brewers Cup finalist. A standalone collector's tin for the truly curious.

The Kit

• 4 coffees × 100g, each in a SOLO Brewing collector's can
• Limited to 280 kits worldwide
• All coffees sourced through The Fermentation Project by James Hoffmann
• Whole beans, roasted to order from early September 2026
• Designed for the global cupping event — 3rd October 2026
• Perfect for filter brewing: V60, Aeropress, Chemex, batch brew

This is not just a coffee kit. It is an invitation to be part of something bigger — a global conversation about fermentation, flavour, and the future of specialty coffee.