Making a 3D printed surface easily cleanable
There is a huge difference between "Certified food -safe" and "is actually perfectly safe for you to use at home" . – Carl Witthoft Sep 18 '18 at 14:54


Regarding certified food safe I point to Ender 3 is capable of food safe printing? - you probably can't get the certification with a 3D printer, but, as Carl said, you might manage a pretty safe at home. So let's assume you go for that.

To make a surface easily cleanable, it is best to make sure that the imperfections of the print are filled up and that there are no undercuts that are not easily cleanable. If you need it smoothed, do it mechanically (e.g. sanding)! Heat or chemicals as a smoothing method are to be avoided, as they can damage the print and accumulate the chemicals used in smoothing in the plastic from where they are released over time.

To make the material both smooth and more safe at the same time, a generous coating with a food-safe lacquer or similar coating would be possible. This also might alleviate the problems with possibly having contaminants in the printing material - we don't know always what is in the printed plastic.