Purpose of the Gourmet Coffee

Jules had a heated argument with Vincent in the bathroom about how the entire body situation was getting out of control and did not want to be kicked back out onto the street by Jimmy.

So Jules is making a big deal about the coffee to distract from the bigger issue at hand. Jimmy cuts in and let’s him know his ploy is not working and for them to do something quick before Bonnie gets home.

Later, the Wolf shows up and has a cup as well and gives an approving smile and nod after tasting the coffee. This eludes to not only was Jules using the coffee as a distraction but it was indeed good.

Nothing too deep, it's just a way of showing QT's character is a middle class boujie hipster and not a gangster like the rest of them.