Papua New Guinea, Simbu Province - Whiskey Barrel Aged

Barrel-Aged Coffee — The Story Behind the Experiment

In this article, we’d love to share the story behind one of our most experimental projects — barrel-aged coffee.

We’ll tell you how it all started, how the process works, and how you can enjoy this unique coffee at home.

How It All Started

Long before I took on the role of Head Roaster at Boardwalk Coffee, I had a dream to recreate something I’d admired for years - a truly distinctive barrel-agedc offee.

I was inspired by well-known specialty roasteries that managed to capture an incredible depth of flavour through this process, and I wanted to give it a go myself.

The secret lies in the natural property of green coffee known as hygroscopicity- its ability to absorb aromas and flavours from its surroundings.

We use this feature to let green coffee beans soak up the beautiful, complex notes left behind in an empty spirits barrel.

Here’s how it happens: the green coffee is placed inside a barrel that once held whisky, rum, or another spirit.

Overseveral weeks, the beans absorb the deep, aromatic essence of the wood and alcohol.

After the resting period, the barrel is opened, the coffee is roasted - and the result is a cup with a subtle alcoholic character but absolutely no alcohol content.

Fort his particular project, our coffee rested for 60 days, and the result exceeded all expectations: smooth, elegant, and layered with flavour.

The Process and What Makes It Unique

Today, there are many experimental fermentation styles in the specialty coffee world -but nothing quite compares to what a barrel can bring.

Thanks to the wooden cask and the spirit’s residual character, the coffee develops a soft, mellow, and complex profile that feels refined rather than overpowering.

The duration of ageing allows us to fine-tune the intensity:

·        Longer ageing brings a bolder, more spirit-forward flavour,

·        Shorter ageing keepsthings delicate and subtle.

Each barrel can hold around two 60 kg bags of green coffee, but for this experiment, we only filled it halfway to allow the beans more space to breathe and absorb aroma evenly.

The barrel is placed on a stand with wheels, so it can be rotated regularly —ensuring every bean takes on the flavour equally.

Everycask is labelled with the coffee’s name and the date of filling, andafter a few weeks, we take small test samples.

Theseare roasted on our sample roaster and cupped to decide whether thecoffee is ready or needs a little more time to mature

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