I know that we must be careful regarding the adding of spices to hot food on Shabbat and I was taught that certain items (like salt) can be added because they are cooking in the process of production. We have used Equal as a sugar substitute in our Shabbat coffee or tea, as it is written on the package (at least it is here in Israel) that it can be used on Shabbat because it has been cooked. Unfortunately, Equal is no longer available where I live. None of the other sweeteners list this kind of info on their packages. Has this been looked into by Mashgichim? Is the information available to us?
Thanking you in advance for your help,
If you want you can contact the OU and ask them, but if that is difficult then there is another option, to put the hot water into a kli shleishi, and then put the sweetener inbto the cup then. This way even if the sweetener has not been precooked, it would not be bishul, as the ingredeients are not known kalei habishul.