Shalom rav, I heared that one should be Makpid not to make
Ground coffee on shaboss since it’s bishul. But we hold one can make instant coffee. My questions is what is the difference between instant and ground coffee, as they are both roasted? I did a lot of research and ground coffee is made using about 400 degrees of heat for about 15 minutes. The bean started of as green and the color is changed to beige and then tk brown. So it seems to me that it has undergone the process of bishal whereby we can then say ein Bishal achar bishal. We say instant coffee is fine, why not
Mu understanding is that instant coffee is also cooked, whereas plain ground coffee, while it is roasted, it isn’t cooked. There are a number of rishonim who hold that there is bishul after roasting.