To taste food or to chew it and then throw it out without anything going down the throat is Makrūh if there is no genuine reason (Udhr).

If it was done due to a genuine reason, it will not be Makrūh. In both cases the fast will not break. A genuine reason could be an ill-tempered husband who could get very angry at the wife if the salt or masala was not proper. Chefs working in restaurants could also be excused if the boss is a hot-tempered person and the job could be at risk if mistakes are made.

However, it would be better to have it tasted by a non-Muslim colleague. One should avoid putting the fast at risk.

أحكام ص 229

Extracted from A Gift for Ramadhan, Page 58.

A Gift For Ramadhan – New 3rd Revised Edition