Main Concepts
1. In an earlier issue (349), we discussed some rules of the melacha of losh. We will briefly review some of the main concepts as an introduction to the current issue. Then we will discuss several common examples.
2. Steps of the melacha. We discussed the two steps of losh. The first is putting water into flour. There is a machlokes if this alone is d’oraisa; strictly speaking, we pasken it is only an issur d’rabanan, but we are machmir to treat it as an issur d’oraisa except in certain specific circumstances (Issue 249, par. 7).
3. The second step is mixing and kneading the water and flour together to create a dough. Everyone agrees this is an issur d’oraisa in a thick mixture.
4. Types of mixtures. We also distinguished between combinable [בת גיבול ] and non-combinable [אינה בת גיבול] mixtures. The Rishonim argue whether just putting water in a non-combinable mixture is assur d’oraisa according to everyone or if the machlokes if it is d’oraisa or d’rabanan applies here too (ibid., 10).
5. Consistency. We also defined and distinguished between thick mixtures [בלילה עבה ] and thin mixtures [בלילה רכה ]. A thick mixture is subject to an issur d’oraisa (ibid., 12), while a thin mixture is only d’rabanan (13). A colored water mixture that has no thickness and pours like water is not subject to the issur of losh at all (14).
6. Shinui in losh. We also mentioned (ibid., 15 and on) that in some cases, a shinui helps. In a thin mixture, a shinui can be done both in the step of adding the water [i.e., changing the usual order, which is considered a minor shinui] and in the step of the mixing [e.g., a bit at a time or a crisscross motion]. In a thick mixture, a proper shinui is only possible in the mixing stage; a shinui does not help in the stage of adding the water.
7. Thick mixture. Thus, one may not prepare a thick mixture on Shabbos, as a shinui cannot be done in the step of adding the water. There are some specific exceptions, e.g., if it could not have been prepared before Shabbos (ibid., 33), if it is food for a baby (34), or if it is done by a non-Jew (35).
