How to get stains out of a polished concrete floor?

Our kitchen and dining area has polished concrete floors throughout. They added two coats of something that was supposed to seal it against stains, but appears to have had no effect.

The worst is food and wine. Anything fatty leaves a dark spot, and red wine is a constant terror. We haven’t come across any way of getting these spots out.

It seems to me that despite the sealing, what we have is basically rock and so anything at all liquid seeps down between the grains. Is there any way of breaking it down in place and drawing it out?

Once we get it clean again, is there any better sealing process we can use for the future? Re-polishing is not an option, too much furniture and disruption. Thanks all!

I think you’ll do best by preparing a poultice of something like TSP and water. Spread the paste over the stain and allow to dry. This should draw the stain out of the concrete.
Good luck

danceswithcats has a good idea with the TSP (trisodium phosphate) and water - another option, if you have access to this product, is Seal Krete OSR (link) - it’s great for stains on concrete and masonry.

Unfortunately, I deal primarily with housepaint and general cleanup - not much concrete unless you want to prime and paint it - so I have little advice for the actual sealing it back up again, except that you’d probably want to look for a 2-part clear epoxy. If a masonry-inclined Doper doesn’t come along and offer an answer first, I’d check in with your local masonry supply folks.

You could try CLR Grease Magnet:

I’ve used this on concrete and stone a bunch of times with usually great results, particularly on oily stains. However, it has always been outdoor, so you would porbably want to test it on a out-of-the-way area to make sure nothing horrible was going to happen. You should be able to get it at the hardware store.

Thanks all! Now to see whether any of these are locally available here in Australia …