What is the proper procedure to make an avocado dressing on Shabbos. The avocado is mushed up by hand prior to the seudah. What it the proper procedure to add oil, lemon juice and spices?
Once the avocado was mashed up, (which is an issue in of itself, see Igros Moshe O:CH 4-74 Tochain 2, that although it is permitted to mash avocado it is preferable not to do so) adding the oil and other ingredients may be done by pouring them on top of the avocado, and then mixing the mixture together with a proper shinui. The reason for this is, that the avocado mash is thick and when the oil is poured on it, it isn’t mixing together at all. The only time we have an issue with needing a shinui (doing it in an unusual way) when pouring the ingredients together (called “nesinas Hamayim”) is when the liquid will seep into the solid. This will not happen here, therefore we don’t have to be concerned with this stage.
The second stage of losh, the actual mixing stage should be done with the regular “shinuim”. For example, the usual way to mix such a dressing would be by making circular motions or “figure 8” motions with the spoon, therefore a shinui for this would be to mix it by criss cross motions- moving the spoon across it top to bottom, then right to left etc. The poskim advise that after making each stroke, we should remove the spoon from the mixture to ensure that we won’t inadvertently switch from a criss cross motion to a circular or figure 8 one. Another option is to mix the ingredients with the handle of a spoon or knife.
O:CH 334-3, Shvisas Hashabos introducton to Losh-6, Pri MIgadim Mishbitzos Zahav 321- 12, The Shabbos Kitchen Chapter 11 ftnt . 10 in the name of R’ Sheinberg Zt”l and others, Orchos Shabbos 6 ftnt. 46. Chazon Ish OC:H 58-6, Igros Moshe ibid Losh 10, 11, Tzitz Eliezer 11-36,