There is a yogurt product on the market now which features a portion of granola that is intended to be mixed in with the yogurt and eaten. May one mix this granola into the yogurt on shabbos or is this not allowed due to losh.
It is hard to give an exact answer because it depends on the proportion of granola to yogurt, but here are the guidelines. If the amount of granola to yogurt is small, and the pieces of granola will not get bound by the yogurt, but will be “floating” separately inside the yogurt, a piece here and there, then it isn’t losh. If however the pieces are going to be close to each other, or if you aren’t sure, then you should mix them together using a shinui. Place the granola on top of the yogurt, (it isn’t losh yet because it is only sitting on top and isn’t getting absorbed inside the yogurt) and then mix the yogurt in a criss cross manner. Namely to move the spoon once across in one direction, i.e. horizontal, and then in then once in the other direction (vertical), and then repeat until the yogurt is mixed. The poskim advise, that it is preferable to take the spoon out of the yogurt between the vertical and horizontal strokes because otherwise one can easily come to make circular motions, which would be losh.
Shulchan Aruch O:CH 324-3, Shvisas Hashabbos Introduction to Losh- 6, Pri Megadim 321- M:Z 12, The Shabbos Kitchen 11ftnt. 10 in the name of R; Sheinberg zt”l, Igros Moshe O:CH 4- 74 losh 10,11, Chazon Ish O:Ch 58-6, Orchos Shabbos 6-39.