Resting Coffee: The Secret to Unlocking Better Flavour

If you're a coffee enthusiast, you’ve likely heard about the importance of freshly roasted coffee. But have you ever considered resting your coffee after roasting? While it might seem counterintuitive to wait before enjoying freshly roasted beans, this step can significantly impact your brew's flavour and aroma.

What Is Coffee Resting?

Resting coffee refers to allowing your freshly roasted coffee beans to sit for a period before brewing. This "resting" phase is a critical part of the coffee preparation process. After roasting, coffee beans continue to release carbon dioxide (CO2) and undergo chemical changes that can affect their flavour. This is why most coffee bags have a one way valve, so the gases can release without oxygen getting in and degrading the beans. 

Check the stamp on the back of your bag of beans so you know the roast date!

Why Should You Rest Coffee?

1. Degassing: Freshly roasted coffee beans produce CO2 as a natural by product of the roasting process. When beans are too fresh, this excess CO2 can disrupt the brewing process, leading to an uneven extraction. Resting the beans allows the majority of this gas to dissipate, ensuring a more consistent and balanced brew.
2. Flavour Development: After roasting, coffee beans need time to develop their full flavour potential. The chemical reactions inside the beans don't stop when the roasting does—they continue to evolve for several days. Resting helps the coffee reach its peak flavour and aroma.
3. Better Brewing: When you brew freshly roasted coffee too soon, the CO2 being released can cause the coffee to bloom excessively (the foam-like expansion you see when water hits fresh grounds), which can disrupt the water-to-coffee ratio. This often results in an under-extracted cup with muted flavours.

What Happens if You Don’t Rest Coffee?

Skipping the resting period can lead to a less enjoyable cup. Here's why:

• Sour or Harsh Taste: If you brew coffee immediately after roasting, the high levels of CO2 can interfere with the extraction process, causing a sour or harsh taste. This is because the gases prevent water from properly penetrating the coffee grounds, leading to an uneven extraction.
• Overpowering Aromas: Freshly roasted beans often have a sharp, overpowering aroma that can mask the subtler, more desirable flavours of the coffee.
• Inconsistent Brew: Excessive CO2 can lead to an uneven bloom, and the extraction will be inconsistent, making it difficult to replicate the perfect cup.

How Long Should You Rest Coffee?

The ideal resting period depends on the roast level and the type of coffee. Here are some general guidelines:

• Light Roasts: These beans generally benefit from a longer rest period of around 7-10 days. The lighter the roast, the more time it takes for the flavours to fully develop.
• Medium Roasts: A rest period of 3-5 days is usually sufficient. The balance of acidity and sweetness starts to harmonise after a few days.
• Dark Roasts: Darker roasts can typically be brewed sooner, often after 1-3 days of rest. These beans degas faster due to their higher oil content and softer structure.

How Do You Know If Coffee Is Stale?

While resting coffee is essential, you also don’t want to let your beans sit too long, as they will eventually go stale. Here's how to tell:

1. Flat Aroma: Fresh coffee should have a vibrant, aromatic smell. If your beans have lost their aroma or smell faintly papery, they are likely past their prime.
2. Dull Flavour: Stale coffee will taste flat, lacking the complexity and richness it once had. You might notice a woody or cardboard-like flavour in place of the lively acidity or sweetness.
3. No Bloom: When you pour hot water over fresh grounds, they should bloom—a puffing up of the grounds due to CO2 release. Stale coffee will have little to no bloom, as most of the CO2 has already escaped.