Decaf

Decaffeinating green coffee beans is a fascinating process with several methods designed to remove caffeine while preserving flavour. Here are the most popular techniques:

CO₂ Processing

This method immerses green coffee beans in warm, pressurised water, causing them to expand and become more porous. Carbon dioxide is then introduced, binding with the caffeine molecules. The water and CO₂ are removed, and the beans are dried.

What makes this method appealing is that it preserves the coffee's natural flavour—none of the carbohydrates or proteins responsible for taste are extracted. The process is eco-friendly too; the by-products are recycled, with water filtered and reused. However, the downside is that this method can be expensive due to the sheer amount of CO₂ required for commercial use.

Sugarcane (Ethyl Acetate) Processing

Sometimes called "natural decaffeination," this process starts with steaming the coffee beans to open their pores. They’re then rinsed in ethyl acetate—a compound that binds to caffeine molecules—effectively removing caffeine. Ethyl acetate can be naturally derived from sugarcane, making this process seem more “natural,” but commercial-scale production often requires synthetic ethyl acetate.

While it’s effective, this method can subtly change the coffee’s flavour profile, adding a fruity note that some might find appealing, while others prefer a purer flavour.

Swiss Water Method

The Swiss Water Method is a chemical-free, organically certified process centred on Green Coffee Extract (GCE). Green coffee beans are soaked in hot water to dissolve the caffeine. To ensure flavour isn’t lost, this water is passed through a charcoal filter that traps only the caffeine molecules while retaining the sugars, oils, and minerals.

The resulting GCE is used to soak new batches of beans, removing caffeine while leaving flavour compounds intact. The Swiss Water Method is praised for being environmentally friendly, maintaining the coffee's original taste, and producing minimal waste.

To find out more about decaf processes, visit our blog post ‘Definitive Guide for Roasting Decaf Coffee’.

The "best" method depends on your priorities. If you're seeking the purest flavour, the Swiss Water Method is often considered superior because it’s chemical-free, organically certified, and retains the coffee's natural profile. From an environmental perspective, it’s also highly sustainable since the process reuses materials and minimises waste.

For those who prioritise a "natural" label, sugarcane processing might be a favourite, especially when ethyl acetate is derived naturally. However, it can alter the flavour slightly, which is a trade-off for some.

CO₂ processing is ideal for preserving flavour without introducing additional notes, but it’s less practical for large-scale production due to its cost. Each method has its unique benefits, so the "best" choice often depends on the balance between flavour, cost, and environmental impact.

Roasting decaf coffee requires extra care due to the structural changes green beans undergo during decaffeination. Here’s what you need to know:

1. Lower Charge Temperature: Start with a lower charge temperature—around 10–15°F below the standard for regular coffee. Decaf beans are more porous and absorb heat faster, so starting cooler helps prevent scorching.
2. Extended Development Time: Decaf beans benefit from a longer development phase after the first crack to build sweetness and complexity. However, don’t overdo it, as this can flatten the flavour or introduce bitterness.
3. Monitor First Crack Carefully: The first crack in decaf coffee can be softer and harder to hear. Rely on visual cues and temperature readings rather than just auditory signs.
4. Avoid Second Crack: Decaf coffee rarely benefits from reaching the second crack. Stopping the roast just after the first crack typically yields the best results, preserving sweetness and complexity without bitterness.

With decaf coffee, it’s all about balance—careful adjustments to temperature, timing, and sensory observation ensure a roast that highlights the beans' unique characteristics without overemphasising their differences from regular coffee. To find out more - visit our blog post ‘Expert Tips for Perfectly Roasting Decaf Coffee’.