I think a little bit lighter background would make the rim of the cup look better, and would also make the coffee stream more-visible. This square crop seems a bit off-balance, with too much visual weight on the left hand side. This is a good test shot or pre-shoot test shot...you can learn a lot about how the cookies actually crumble by shootin' those cookies....errr...coffees I mean!!!
Maybe you could tape a medium-toned piece of paper behind the cup and coffee stream, and then shoot the coffee being brewed with that lighter backdrop??? The choice of cup is also gonna be very important...either white, or black, or clear glass, reflective or not, and so on...