Coffia roasted for ESPRESSO (3rd wave) is usually slightly darker than Filter Roast, so the acidity is slightly muted. It is so because espresso brewing method amplifies the acidity in comparison to other brewing methods. Downside to going darker is slight suppression of flavours. Modern espresso is aiming to equilibrium of flavors and acidity with great aromas.
If you prefer darker roasts with pronounced bitterness and muted acidity, we recommend our Old School collection