PRESALE - The Fermentation Project — James Hoffmann × Lucia Solis

DESCRIPTION

Everything you've been told about fermentation is probably half right.

"Anaerobic." "Extended." "Yeast-inoculated." The words are everywhere. The understanding isn't. Nobody ever had the chance to taste the plain version of the same coffee sitting right next to the fermented one — until now.

James Hoffmann and microbiologist Lucia Solis sourced a single lot of coffee from Finca San Miguel Urias in Antigua, Guatemala. Same farm, same harvest, same green. They split it into four parts and processed each one differently. The variable: fermentation only. Everything else, identical.

We're one of around 120 roasters worldwide taking part. We roasted all four lots to the same profile — same development, same curve — so what's in your cup is the fermentation talking, not us.

Four bags. Four processes. One direct question answered: what does fermentation actually do?

Join James Hoffmann's live global tasting on YouTube on 3 October 2026 at 15:00 London time. Or go at your own pace. Either way, this is the most interesting 400g of coffee we've shipped this year.

THE KIT — FOUR COFFEES

1 — NO FERMENTATION

The Control.

Before anything happens to coffee, there's this.

No fermentation. The cherry is pulped and the seed goes straight to drying without any microbial activity in between. This is the baseline — the raw truth of the bean before any processing has a chance to shape it. Understated, clean, a direct line to the terroir.

Every other coffee in this kit is a deviation from this one. Taste it first. Taste it last. Return to it. It's the anchor.

Process: Washed, no fermentation
Notes: Clean · Mild · Terroir-forward

2 — TRADITIONAL FERMENTATION

The Classic.

This is how most of the world's coffee is processed and most people have no idea.

After pulping, the coffee sits in open-air tanks while naturally occurring microbes — whatever's in the air and on the farm — break down the remaining mucilage. No added cultures, no control beyond time and temperature. The same process produces wildly different cups depending on altitude, weather, and the specific microbial population at that farm on that day.

This is fermentation as it has always been done. The point of comparison. The one that makes everything else legible.

Process: Traditional open fermentation, natural microbial population
Notes: Familiar · Rounded · Character-driven

3 — LACTOBACILLUS INOCULATED

The One That Hits Different.

This is the one.

The coffee is inoculated with lactic acid bacteria — Lactobacillus — introduced deliberately rather than left to chance. Lactic acid bacteria produce organic acids: the kind that drive fruitiness, freshness, and what people in coffee call "brightness." The fermentation is controlled, directional, and repeatable.

If this kit has a showstopper, it's probably this one. More complex than B, more alive than A. The kind of cup that makes you put it down and go back for another taste to make sure you tasted what you tasted.

Process: Lactobacillus inoculated, 48 hours
Notes: Fruit-forward · Fresh · Complex

4 — WINE YEAST

The Full One.

Saccharomyces cerevisiae — the same family of yeast that makes wine — is introduced to the fermentation. Where Lactobacillus builds acidity and brightness, wine yeast builds body, texture, and a broader, rounder flavor profile. The focus is on precursor development: compounds that form during fermentation and determine how the coffee expresses itself in the roaster and in your cup.

This one sits differently. Heavier, more layered. Not louder — deeper.

Process: Wine yeast inoculated, Saccharomyces cerevisiae
Notes: Full-bodied · Rich · Layered

KIT CONTENTS

• Coffee A: No Fermentation — 55g
• Coffee B: Traditional Fermentation — 55g
• Coffee C: Lactobacillus Inoculated — 55g
• Coffee D: Wine Yeast — 55g
• Total: 220g

Notes: Full-bodied · Rich · Layered

NOTES:

All coffee will be roasted in the week of the 7th of September and shipped on the 17th.
This to ensure there is sufficient time for the coffees to reach everyone in their best consition for the event.