DH did that while learning how much water to put in the new maker. I finally asked him to pour the cool coffee over the hosta -they love it. Meanwhile, try using lemon juice/water (50/50); a couple sprays and swop with a sponge, a splish of water to rinse, or just keep a sponge in a small bowl of the mixture to swop and then rinse. I never found anything that would actually protect the sink's finish from repeated coffee or tea stains, so the alternative is to have the clean-up as fast and easy as possible, and clean immediately after pouring.

Pour the coffee directly into the drain....
I remember now why I have a stainless steel sink!
Linda C

I'm with Linda. Aim that puppy right over the hole. I did this to myself in the last house and the only time my sink looked nice was right after I cleaned it with Soft Scrub. I also switched to a SS sink in this house. You can also keep just a little bit of bleach in a spray bottle of water and mist the sink at the end of the day. I've found a Mr. Clean Magic sponge cleans my sink really nice. They are too pricey for me to use all of the time, though.

Gloria

Bar Keeper's Friend will get coffee and other food stains off a porcelain sink.

For all-over perfect cleaning of any sink: Plug sink after water is running as hot as possible. Add One Cup of cascade or similiar product - swish to dissolve - fill sink to brim. Leave overnight. 99% of stains will be gone in the morning. Touch up a bit with scrub sponge if needed - it will come off ASAP.

We drink a whole pot of TEA in the morning which stains worse then coffee!!! For touch-ups in-between --- pour a little bleach - run from the fumes - and then come back and just rinse.

TNLady

I keep my sink stain free with a spritz of Clorox Clean-Up in the sink. Saves wear and tear on the finish from abrasives. Also keeps bacteria down.