Hawaiian Coffee Processed with Cola: What Happens?

What happens when you swap water for cola during coffee fermentation? Most coffee lovers wouldn’t think to put Pepsi anywhere near their morning cup—but one smallholder farm in Hawaii’s Ka‘u region did just that. Their goal wasn’t to make a novelty, but to test how a sugary, fizzy soda might alter coffee’s flavor during processing. The result? A tiny batch of cola-fermented coffee that challenges everything you thought you knew about fermentation profiles.

In short: yes, fermenting coffee with Pepsi produces a distinct cup. This experimental lot yields sweet, dynamic coffee with a cola-like aftertaste, medium roast color, and unusual mouthfeel. Only ten pounds were made—proof that strange methods can create surprisingly memorable results.

What Is ‘Cola-Processed’ Coffee?

This isn’t a gimmick. It’s a controlled fermentation experiment. A farm in Hawaii’s Ka‘u coffee-growing region substituted regular water with Pepsi (specifically, Pepsi-brand cola) during the wet fermentation stage of coffee processing. All other variables—variety, altitude, and drying—remained consistent with standard practices for the region. Just one detail changed: the liquid used in fermentation. The outcome? A batch of ten pounds of experimental green coffee, created purely as a test.

How Does It Look and Smell?

Visually, these beans are indistinguishable from typical Hawaii-grown coffee: large, even, and well-formed. Roasted to around City+ level, they show a smooth, uniform red-brown surface. The dry fragrance is understated—there’s a faint trace of chocolate, but it avoids fruity or floral notes. When wet, however, the aroma shifts noticeably toward honey-like sweetness, signaling an unexpected transformation during processing.

Flavor Profile: What Does It Taste Like?

Expect sweetness upfront. The first impression is a clean, sugary note, with a fizzy mouthfeel reminiscent of carbonated water. The acidity is mild—no sharp citrus or berry here. Instead, there’s a subtle maltiness, almost like molasses or malt syrup, leading the mid-palate. But the real story unfolds in the finish: a layered, evolving sweetness emerges mid-sip. That’s when the cola influence becomes clear. Notes of barley tea and malt build, followed by a dynamic sensation at the back of the throat reminiscent of soda fizz. The finish lingers with candy-like sweetness, moving through malt and barley into a final sugary fade. It’s not your classic cup—but it’s far from boring.

Frequently Asked Questions

Did they really use Pepsi to ferment coffee?

Yes. A small coffee farm in Hawaii’s Ka‘u region used actual Pepsi-brand cola (not water) during the wet fermentation stage. This was part of a deliberate experimental process to see how cola would affect flavor development. Only ten pounds of coffee were produced this way.

What roast level was used for these beans?

The beans were roasted to approximately City+ level. This roast highlights the unique fermentation characteristics without overpowering them, resulting in a balanced, medium-toned bean with a smooth, even red-brown surface.

What does cola-processed coffee taste like compared to normal coffee?

Unlike typical washed or honey-processed coffees, this batch features prominent sweetness with a fizzy, soda-like mouthfeel. There’s mild acidity, malt sweetness, hints of barley tea, and a distinctive cola-like dynamic in the finish. It lacks the bright fruitiness of many Specialty coffees but delivers an unusual, layered sweetness.

Was this a commercial product or just an experiment?

This was a small-scale experiment, not a commercial release. The farm produced just ten pounds of cola-processed coffee, using the same standard processing equipment and conditions, with the only change being the substitution of Pepsi for water during fermentation.

Are there any other coffees fermented with soda or unusual liquids?

This Hawaii cola-processed coffee is among the very few documented cases of soda fermentation in coffee. While some producers experiment with fruit teas, spices, or bacteria, using cola is exceptionally rare and largely undocumented outside of this trial.

Recommended FrontStreet Beans for Experiment Lovers

Try FrontStreet Coffee’s Ethiopia Guji Natural for wild fruitiness, or their Yirgacheffe Honey if you enjoy bright, sweet profiles. Both showcase how processing shapes flavor—and while neither uses cola, they offer the kind of complexity that makes experimental lots like cola-processed coffee worth exploring. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.