How Long Should You Rest Coffee After Roasting? A Guide to Degassing

Freshly roasted coffee often smells divine, but if you’ve ever brewed it right after roasting, you may have noticed muted flavours or an overly gassy taste. That’s because freshly roasted coffee needs time to "rest," a process called degassing. But how long should you wait before brewing your beans? Let’s delve into the science and provide practical recommendations for coffee enthusiasts.

What Is Degassing?

Degassing refers to the release of carbon dioxide (CO₂) that builds up inside coffee beans during roasting. As the beans are heated, gases, including CO₂, form within their cellular structure. After roasting, CO₂ escapes gradually over time.

The Science Behind It
A study published in the Journal of Agricultural and Food Chemistry found that freshly roasted coffee releases most of its CO₂ in the first 24–48 hours, but smaller amounts continue to escape for weeks. The rate of degassing depends on factors like roast level, grind size, and storage conditions.

How Long Should You Rest Your Coffee?

There’s no one-size-fits-all answer, as optimal resting times depend on the coffee type and brewing method. However, here are some general guidelines:

Espresso (Rest Longer)

• Recommended resting period: 7–14 days.
• Why: Espresso brewing is highly sensitive to CO₂. Too much gas disrupts the pressure and extraction, leading to sour or inconsistent shots. A longer rest ensures a more stable crema and balanced flavour.

• Recommended resting period: 3–7 days.
• Why: Filter brewing methods like pour-over are less affected by CO₂. Resting allows for clearer, more vibrant flavours without sacrificing aroma.

• Recommended resting period: 2–5 days.
• Why: Darker roasts degas faster due to their porous structure, making them ready to brew sooner.

• Recommended resting period: 5–10 days.
• Why: Denser light-roast beans hold onto CO₂ longer and benefit from extended rest to allow their nuanced flavours to shine.

What Happens If You Don’t Rest Coffee?

• Underdeveloped Flavour: Freshly roasted coffee might taste flat or overly acidic because CO₂ blocks water from properly extracting the coffee’s soluble compounds.
• Unstable Crema: In espresso, excess CO₂ can create an overly foamy crema that dissipates quickly.
• Inconsistent Brewing: The presence of CO₂ can lead to channeling in espresso or uneven extraction in other methods.

Storage Tips During Resting

To preserve freshness while resting:

• Use airtight containers: CO₂ naturally pushes out oxygen, but improper storage can allow oxygen to re-enter, leading to staleness.
• Store in a cool, dry place: Heat and humidity accelerate the degradation of coffee.
• Avoid refrigeration: It can introduce moisture and unwanted odours.

The Science of Degassing: A Closer Look

Research indicates that the rate and duration of degassing depend on a coffee’s roast profile and grind size. Lighter roasts degas more slowly than darker ones because of their denser structure. Grinding coffee accelerates degassing by exposing more surface area.

For example, the Journal of Food Science noted that ground coffee loses up to 70% of its CO₂ within minutes, which explains why grinding fresh beans just before brewing is critical for retaining flavour.

Key Takeaways

• Resting coffee is essential for optimal flavour and aroma.
• The recommended resting time varies based on roast profile and brewing method.
• Proper storage helps maintain freshness while coffee rests.

Ready to Brew the Perfect Cup?

Now that you know the importance of degassing, why not explore our freshly roasted coffee? Our single-origin and competition-grade beans are roasted to order, ensuring maximum freshness for your brewing journey. Check out our collections here.

By giving your coffee the time it needs to rest, you’ll unlock its full potential and savour every sip. Happy brewing!