Specific Applications of Lisha – Kneading on Shabbos

Lisha by a Cooked Food

Food that has already been cooked and softened is no longer subject to the melacha of lisha on Shabbos as it is already consider to have been prepared for consumption and additional lisha is of little consequence to its preparation. However, one should employ a mild ‘shinuy’, alteration to the way one would normally do so, by only mixing small amounts of the cooked food at a time.
Therefore, if one has boiled potatoes, when one is permitted to mash them (per hilchos tochen, where they must have already been significantly softened and mashed by the cooking process, or doing so with a shinuy in the case of need), one may mash and mix them with gravy etc though only doing so in small quantities at a time (SSK 8:24, BHL 321:14 D”H Shema).
One may similarly mix in cinnamon, raisins etc to porridge that has already been cooked before Shabbos (SSK 8:25).

Baked goods may be dipped into liquid (even hot drinks, if in a kli shlishi) even though the liquid will absorb into the food, as this is considered to be softening and crumbling the baked food, rather than kneading it. For example, one may dip bread into soup, or eat cornflakes with milk.
However, if the bread breaks apart in the liquid it is forbidden to stir the liquid to recombine the fragments. In a similar vein, one may not mix matza meal with a liquid to form a mass (SSK 8:27, MB 321:57).

Where two substances were previously mixed together and somewhat (but not fully) separated, it is permitted to mix them so they fully recombine.
For example, if there is oil floating on top of peanut or almond butter, it may be mixed back in, as there remains oil that mixed in to the butter below. However, this should be done gently rather than forcefully, which is a mild ‘shinuy’, a change from how they would normally be mixed, so this does not look similar to lisha (SSK 8:7, fn24).

Many have the practice to make a salad of chopped egg and onion mixed with oil in the normal fashion on Shabbos, without employing the shinuyim we have previously described. This is despite the fact that the salad is in effect made by combining together different substances into a single, thick mass. SSK outlines various arguments to justify this practice.
Nonetheless, he notes it would be good to use the two shinuyim we outlined by the making of thick and thin masses when making the salad (by reversing the order of adding the solid and liquid, and stirring in an unusual fashion) and the optimal practice would be to prepare it in advance of Shabbos (per the halacha about thick mixtures) (SSK 8:28).
There are other melachos we have previously covered that one must also be careful of when making the salad. Due to borer, one should only peel the egg and onion within the timeframe of ‘immediate use’ that we have previously defined and if any egg shell gets mixed in to the egg, one should ideally pick out the egg rather than the shell, or at least one should remove the piece of shell with a meaningful amount of the egg. In addition, due to tochen, one should only cut the onion into pieces that are a little large and again, only within the timeframe of immediate use (there is no issue of tochen on the egg as it doesn’t grow from the ground) (SSK 8:28).

Whilst this is no longer so common as we have easy access to soap, in the absence of soap some wash their hands with the assistance of sand, as its abrasive texture helps to clean dirt from the hands. Sand may be used as part of the washing process if two conditions are met:
- Firstly, that it was designated for that use prior to Shabbos; otherwise, sand is muktzah
- Secondly, that one does not mix the sand into water before using it, due to the prohibition of ‘lisha’, kneading. One may, however, use the sand when one’s hands are moist, as any ‘kneading’ that takes place is being done in an unusual fashion and without actively pouring water onto the sand. (R 326:10, MB 28, SSK 14:19)