Greasy kitchen plaster

I am after some advice on removing grease from bare plaster before tiling on it. Our kitchen was completely replastered about 18 months ago and due to a combination of laziness and other priorities I am only now getting round to tiling. Because of this I now find myself in the situation where the plaster behind the cooker and to a lesser extent in other places is splattered with grease.

I've given it a wipe over with a slightly damp sponge and you can clearly see areas where the porosity of the plaster is reduced by the grease.

What is my best course of action to do something about this? Some people seem to suggest sugar soaping to remove the grease and then priming and tiling, others suggest that this would be a bad idea as the sugar soap would soak in to the plaster and be difficult to remove and cause issue with adhesion.

The tiles are 200mm x 100mm ceramic and I was intending to use a 1:1 diluted Bal primer and pre mixed adhesive

Any help or tips would be greatly appreciated.

Hot soapy water has always been a good method to remove grease. You can also use degreasers if particulary bad.

Is there no issue with the detergent\degreaser soaking in to the plaster and affecting the adhesion of the tile adhesive?

i had a similar problem on plasterboard and did use washing up liquid and a brush. i also scraped out a couple of the worst bits, although nothing very deep. levelled it out with the adhesive.

il get shouted at for not using bagged stuff but i used mapei premixed mapegrip d2 and all went well.

i might be wrong but i would have thought there would be more cause for concern if you were painting rather than tiling?

as above....then score the area with a stanley blade to give it a key,then use your acrylic primer...then tile away.