The Fermentation Project Tasting Kit: Kustomcoffee Edition

One coffee. Four fermentations. One question: what does fermentation actually do to flavor?

We're proud to be a participating roaster in The Fermentation Project, a global cupping event created by James Hoffmann (2007 World Barista Champion and the most-watched educator in specialty coffee) and fermentation scientist Lucia Solis.

On Saturday, October 3, 2026, coffee lovers around the world will cup these same four coffees together, guided live by James Hoffmann. You'll be tasting in real time alongside thousands of people on every continent — including us, right here at Kustomcoffee.

The farm created four versions of one coffee to isolate what fermentation and processing do to it. People rarely get to taste a "fermented" coffee next to its own unfermented control — this project makes that comparison possible for the first time, side by side, in your own cup.

That means when you taste these four coffees together, any difference you notice — brightness, body, sweetness, mouthfeel, aftertaste — comes from how the coffee was processed after picking. It's the cleanest side-by-side comparison most coffee drinkers will ever get to do at home.

We've had the green coffee in-house since late July, and we're sample roasting now to lock in the ideal profile for each of the four lots — because doing this comparison justice means every coffee needs to be roasted with equal care, not roasted to hide its differences.

This is a unique event, and our kits are limited. When they're gone, they're gone — we won't be roasting or restocking once preorders close mid-September.

What's in the kit

Four 150g bags of whole bean coffee. If you want to retain the mystery till you cup, we can blind label them with just the coffee numbers, on request. Please check the Blind Samples box if you'd like us to label your shipment with numbers 1 through 4 instead of the coffee names.

The Coffees

Mechanically Washed

No fermentation at all. Mucilage removed mechanically right after harvest, so this cup's profile comes purely from growing practice and genetics — your reference point for the other three.

Wild Fermentation

A traditional 48-hour submerged ferment using local, naturally occurring wild microbes.

Lactobacillus Fermentation

A controlled 48-hour submerged ferment inoculated with a specific Lactobacillus culture, boosting organic acid production.

Saccharomyces Yeast Fermentation

A controlled 48-hour submerged ferment inoculated with saccharomyces yeast, boosting flavor precursor production.