In the newspaper “Hapeles” published in Israel, an ad published in the name of Rabbi Mordechai Gross shlit’a says that there is a problem with the coffee produced by “Elite” Israel . It is forbidden to use it regularly on Shabbat; it needs to be made only in a “Kli Shlishi”.
Note that Elite makes two kinds of instant coffee. One of them is identical to Taster’s Choice/Folger’s (except for minor difference in taste). Do you know if he’s paskening about instant coffee in general or about Elite’s fine powder “Israeli Namess”?
I use iruy kli sheini (which has the din of kli shlishi) for all instant coffee. I’m choshesh that the drying process is considered tzliyah, and yesh bishul achar tzliyah.