Does freshly roasted coffee taste best?

Couple of months ago, I ordered a bag of coffee beans from the roasters site. The package said the coffee was roasted 3 days back. I was excited thinking that the coffee would be so beautiful as it is very fresh.

Soon, I made a cup with that and I was surprised. In a bad way. It tasted flat, as if I made the coffee with room temperature water.

Before calling this a bad coffee, I wanted to validate myself and I looked if people had any reviews online. There were a few praises on reddit. And then, after some more research, I discovered that the coffee should be rested.

Let's see why.

Degassing is crucial

As soon as the coffee is roasted, the coffee is fresh, but not ready. It has a lot of CO₂ trapped in it, based on how dense the coffee is.

The CO₂ trapped inside the beans actively repels water. When you pour hot water over grounds that haven't fully degassed, the CO₂ bubbles interfere with the water's ability to uniformly saturate all the coffee particles. This leads to an uneven extraction, where some grounds are over-extracted and others are under-extracted.

Because degassing prevents an uneven extraction, it allows for a more balanced and refined flavor profile. Coffee brewed too early can taste overly bright, acidic, or sour due to excess CO₂. Resting allows the more subtle, complex, and sweet notes to emerge and balance the flavors.

This is why I had a bad experience with fresh coffee.

Pour over vs Espresso

In manual brewing methods like pour-over, the "bloom", where the first pour of hot water is done and the coffee bed swells up, is a result of CO₂ escaping. While a good bloom indicates fresh coffee, an overly aggressive one from beans that have not rested can disrupt the brewing process and prevent proper saturation.

And in espresso, uncontrolled gas release can lead to channeling, where water forges uneven pathways through the coffee bed or puck. This results in a poor extraction that lacks sweetness and can cause a watery mouthfeel and a less-than-ideal texture.

Coffee being used for espresso might need more resting compared to the manual brewing methods.

Light vs Dark Roasts

Light roasts are more dense than Dark roasts. Which means, light roasts need more time to degass than the dark ones.

Typically, light roasts can take from 7 to 14 days to properly degass and achieve peak flavour. Where as, dark roasts are quick and can be brewed with in 4 days.

Best practices

So, how do we let the coffee rest, properly?

The best way is to keep it as is.

Almost all coffee bags have a one way valve, where the gases from inside are let out and no gas from outside is let in. This is crucial.

If we let oxygen in, coffee starts becoming stale. So the one way valve just lets the degassed CO₂ come out.

The environment should be not too hot or not too cold, leaving it in your room should be okay. It's best if the place is dark, so maybe in a drawer. Fridge is a no-go as coffee is hygroscopic, meaning it readily absorbs moisture and odors from its surroundings, meaning, bad coffee.

Roasters typically tell you how long should the coffee be rested, either on the packaging or on their website. If not, we can follow the above days based on the coffee.

Knowing this fundamentally changed when I order my next bag of coffee at home. It used to be after I finish the current stash, but now it's a week in advance.

When I am left with ~120g of coffee, I start searching for my next beans. By the time I finish the current ones, new coffee is both fresh and ready.

That’s all I have. Have a caffeinated weekend.

See you.

Keep on brewing!