Hi, Is blowing bubbles for a child considered the melacha of "Zoreh"?

Thank you for your question. The work Shmirat Shabbat KeHilchatoh allows children to blow soap bubbles on Shabbat, but advises against adults doing so (Chapter 16,30). The prohibition involved is that of "nolad", changing the form of the soapy water into a bubble, especially where it is done with intent, as opposed to washing the dishing when this might happen unintentionally. The reason to be lenient is the fact that the bubble has no permanent state. However in relation to the melacha of "Zoreh" most authorities believe that it only applies when one "winnows" to the wind a mixture of good and bad and allows the wind to separate the two. If so, this would not apply here, where the wind carries off the bubbles with no separation at all. It is true that according to the Rema's comment (319, 17) that one should refrain from spitting into the wind, there may be a problem of "zoreh" with blowing soap bubbles into the wind. None the less, the overwhelming opinion of the codifiers is to reject this ruling of the Rema – see for example the Mishna Brurah there, and the Biur HaHalacha. This is because they understand the malacha to be as we stated – an act of separation – and not just using the wind to spread things out. So, in conclusion, there is certainly room to allow a child to blow bubbles on Shabbat. Blessings.