Some Rules About the Melacha of Losh
The Melacha
1. Losh is one of the 39 forbidden melachos on Shabbos. Losh is defined as adding a liquid, e.g., water or oil, to a powdered raw material, e.g., flour, and connecting, gathering, or kneading them together until a paste is formed. The issur of losh applies both to food items [even ones that do not grow from the ground (שו''ת אג''מ או''ח ח''ד סי' ע''ד לש אות י''ג )] and to non-food items, e.g., mortar, cement, coloring agents, etc.
2. Common shailos. It should be noted that while everyone knows it is an av melacha to make actual dough with flour and water on Shabbos and no one does that, losh is nevertheless one of the most common melachos in Jewish homes. There are many common examples on Shabbos in the kitchen or at the table, and many people are unaware of the halachic details and various cases of the melacha of losh due to the many opinions as to the basic definitions. Thus, we saw a need to go through common issues so that people will know and be careful not to violate the serious issurim of Shabbos.
3. Understanding the halachic breakdown of losh requires the presentation of many important introductions, principles, and concepts, as explained by the poskim (במ''ב סי' שכ''א סק''נ ועוד ).
Steps of the Melacha
4. The Tannaim and poskim argue whether different steps of the melacha of losh are assur d’oraisa or d’rabanan, as will be explained.
5. Putting water into flour. Rebbi (בגמ' שבת דף י''ח ) holds merely putting water into flour [even without kneading the mixture] is the melacha d’oraisa of losh, as the water mixes with the flour and creates the beginnings of a paste.
6. Mixing the water and flour. R’ Yosi ben R’ Yehuda (שם ) holds the issur d’oraisa of losh is only when one kneads the dough. He holds merely putting water into flour is not assur d’oraisa, though he agrees it is assur d’rabanan (מגיד משנה פ''ח שבת הט''ז, ביאה''ל סי' שכ''ד ס''א ד''ה אין ).
7. Halacha. Most Rishonim follow R’ Yosi ben R’ Yehuda, who holds putting water into flour is an issur d’rabanan, and this is the implication of the Mechaber (שו''ע סי' שכ''א סט''ז ). However, some Rishonim pasken like Rebbi (ספר התרומה, י''א בשו''ע שם ), and some poskim follow this as a chumra l’chatchila (דרכ''מ סי' שכ''ד סק''א, ח''א כלל י''ט ס''א, שו''ע הגר''ז ס''ג, מ''ב סי' שכ''ד סקי''א ), but b’dieved one may be meikel (ביאה''ל סי' שכ''א סט''ז ד''ה אבל ).
Types of Mixtures
8. Combinable [בת גיבול]. The Gemara discusses two types of mixtures. One type is combinable. For example, water and flour combine well via kneading to form a single mass which cannot be restored to its original components even if the dough is allowed to dry out.
9. Non-combinable [אינה בת גיבול]. Another type of mixture is non-combinable, i.e., the ingredients will not form a single mass, e.g., water and ashes – even after they are mixed well, they do not form a paste. The ashes are gathered together and held by the water, but they do not combine into a single mass.
10. Abaye holds that R’ Yosi ben R’ Yehuda only said there is no issur d’oraisa to put water into flour (above, 6) in a combinable mixture since the main melacha is done when the paste is kneaded, not when the water is added. However, he would agree just adding water is an issur d’oraisa in a non-combinable mixture; many Rishonim pasken like Abaye (ביאה''ל סי' שכ''ד ס''א ד''ה אין ). Rav Yosef holds there is no difference – according to R’ Yosi ben R’ Yehuda, the issur of just adding water is only d’rabanan even for a non-combinable mixture; many Rishonim pasken like him (חזו''א ס'י נ''ו סק''ג ).
Consistency
11. The Gemara in Shabbos (דף קנ''ו ע''א ) also differentiates between a thick mixture and a thin mixture, as will be explained.
12. Thick mixture [בלילה עבה]. A thick mixture, i.e., one that cannot be poured from one dish to another (חזו''א סי' נ''ח סק''ט ), is subject to the issur d’oraisa of losh. Thus, Chazal are more machmir on this in certain ways.
13. Thin mixture [בלילה רכה ]. A thin mixture is a more diluted mixture that can be poured from one dish to another, but it is still a “dough,” i.e., it is semisolid, not liquid (חזו''א שם ). It is only subject to an issur d’rabanan, so there are certain kulos, as will be explained.
14. “Cloudy water.” Something completely liquid that can be poured like water is not considered a mixture and is not subject to any issur of losh. Thus, one may mix water with powdered milk or sugar, and one may make a drink using water and flavoring powder, as even after they are combined, the resulting liquid pours like water (חזו''א נ''ח סק''ט ד''ה קנ''ו, קובץ מבית לוי ח''ח עמ' יח אות ח).
Shinui in the Kneading Process
Kneading with a Shinui
15. The Gemara in Shabbos (דף קנ''ו ע''א ) explains that in certain cases, losh is mutar when done with a shinui. This is not under the general hilchos Shabbos rule that one is potur for something done with a shinui, as other melachos are still assur d’rabanan with a shinui. Rather, the heter for losh with a shinui is because for some actions, Chazal determined that a shinui is a deficiency in the act of the melacha, and it is mutar even d’rabanan. We will explain.
Shinuyim in the Steps of the Melacha
16. There are two steps to the melacha: putting water in the flour and kneading them together (5, 6). Accordingly, there are different variables as to what constitutes a valid shinui for each step.
17. Shinui in adding the water. The Gemara says that in a thin mixture, which is only subject to an issur d’rabanan (13), one can do a shinui from the usual order in the stage of adding water. If, during the week, one usually first pours water and subsequently adds the flour, he should switch the order on Shabbos – first put in the flour, then add the water. The same is true in reverse.
18. Even if one did a shinui in adding the water, some say he must still do some minor shinui when combining the ingredients (תרומת הדשן סי' נ''ג, עי' מ''ב סקנ''ז ). Others are meikel and hold a shinui in combining is unnecessary (דרישה, סתימת שו''ע סי''ד, חזו''א סי' נ''ח ד''ה ומשמע ).
19. With a mixture which only has a bit of water in the flour so that it is thick after the combining and kneading, a minor shinui like adding the ingredients in a different order is not enough to permit an issur d’oraisa of a thick mixture. This is based on the minhag to be machmir to consider just adding water an issur d’oraisa with a thick mixture (see 5 above). Thus, one may not make a thick mixture on Shabbos even with a shinui, as there is no shinui great enough to permit the step of adding the water, with the exception of certain cases that we will discuss (32).
20. Shinui in the kneading. There are also multiple types of valid shinuyim in the kneading stage mentioned in the poskim, e.g., a bit at a time, mixing in a crisscross pattern, and others, as we will explain (21). Because these shinuyim are proper shinuyim in the manner of kneading, they even help for a thick mixture, which is subject to the issur d’oraisa.
Methods of Shinui in Kneading
21. Throughout his words, the Shulchan Aruch mentions several ways of doing a shinui in the kneading. Each time, he mentions a different shinui, corresponding to the food he is discussing. The poskim imply that any of these shinuyim works with any food in a similar case; the poskim just spoke about common cases. The main thing is it should be a clear change from the normal way to knead during the week (כמבואר בשו''ע הגר''ז סי' שכ''ד סק''ג, אג''מ או''ח ח''ד סי' ע''ד לש אות ט', פסקי תשובות סי' שכ''א אות כ''א ). We will now go through the different ways mentioned by the poskim.
22. A bit at a time. One type of shinui is kneading a small amount at a time for something one would usually knead a lot of at a time during the week (שו''ע סי' שכ''א ס''א ). One may mix it with his hand or with a utensil (חזו''א או''ח סי' נ''ח סק''ה ).
23. Crisscross. Another form of shinui is mixing in a crisscross motion with the spoon, i.e., moving the spoon side to side lengthwise across the dish, even several times (ביאה''ל סי' שכ''ד ס''ג ד''ה ומעביר, חזו''א שם סק''ו ), and then moving the spoon in the same motion widthwise across the dish. This process is repeated until the components are well-mixed (שו''ע סי' שכ''ד ס''ג ).
24. Gently. If something is usually mixed quickly (איל משולש פ''ג ס''כ), mixing it slowly and gently is a valid shinui (שו''ע סי' שכ''א סט''ו סט''ז).
25. Using the hand. Mixing with one’s hand or finger is a valid shinui for things normally mixed specifically with a utensil (רמ''א שם סט''ז ).
26. Shaking the dish. One may perform a shinui by shaking the dish (מ''ב שם ס''ק ס''ג ) or pouring the mixture from one dish to another (שו''ע סי' שכ''ד ס''ג ) several times until it is well-combined (שש''כ פכ''ב הע' נ''ג ).
27. Different utensil. If one normally mixes something with a spoon or fork, it is enough of a shinui to mix with a knife or the handle of a spoon or fork (שו''ת אג''מ או''ח ח''ד סי' ע''ד לש אות י''א, שו''ת מנחת יצחק ח''א סי' ע''ד אות ה').
Some Detailed Halachos of Losh
Adding a Thick “Liquid” to Flour
28. Mayonnaise with flour. We mentioned an issur of merely adding water to flour (5). However, that is only something like water or oil, which seeps into the flour and mixes with it. If something is thick and sits on top, almost like a solid, and does not seep in, e.g., mayonnaise, there is no issur to merely add it to flour (שביתת השבת הק' למלאכת לש סק''ו, ארחות שבת פ''ו אות ח''י ). However, the mixing must be done with a shinui, e.g., with a crisscross motion.
Diluting a Paste
29. If a paste was mixed well before Shabbos, one may add water on Shabbos and mix it in since doing this does not help knead the paste at all; it merely dilutes it. In fact, this is the opposite of losh, which is mainly done to bind ingredients to each other (ביאה''ל סי' שכ''א סט''ו ד''ה יכול ).
Making Techina on Shabbos
30. From raw techina. If, when making techina [made from ground sesame seeds] from raw techina, one first adds just a bit of water, the techina stiffens as a result of the parts of the techina all coming together. This is a problem of creating a thick mixture, which is assur on Shabbos. Thus, from the beginning one should add a lot of water. Then, a paste is not made; on the contrary, the techina is diluted to become more liquidy.
31. Diluting techina. Similarly, one may dilute techina on Shabbos. Meaning, if one made techina before Shabbos and mixed it well and then wants to add water on Shabbos to dilute it further, he may do so since adding water to dilute is the opposite of losh.
Cases Where One May Make a Thick Mixture with a Shinui
32. We mentioned above (19) that one cannot make a thick mixture on Shabbos because there is no shinui great enough according to the opinion it is an issur d’oraisa to add the water. However, there are cases of thick mixtures [which are combinable (לדעת המ''ב בביה''ל סי' שכ''ד ס''ג סוד''ה אין ), or even non-combinable (לדעת החזו''א סי' נ''ו סק''ג )] where the poskim were meikel to rely on the main halacha that there is no issur d’oraisa to just add water (7); accordingly, a shinui in the mixing helps, as explained above. We will list some cases.
33. Could not be done before Shabbos. A food that cannot be made before Shabbos because it will not taste good may be made on Shabbos with a shinui in the mixing. This heter applies even to a thick mixture (ט''ז וא''ר, הובאו בשעה''צ סי' שכ''א סקפ''ד ). However, it is proper to also do a shinui in the step of adding the water (מ''ב סי' שכ''א ס''ק ס''ח ).
34. Baby food. The poskim allow one to make a paste on Shabbos to feed a baby if he does a shinui in the mixing (חזו''א סי' נ''ח סק''ח ד''ה כשכותשין ).
35. Non-Jew. With no other choice, one may have a non-Jew add water to the flour. Since amira l’akum is only assur d’rabanan, there is no need to be concerned for the machmir opinion in the step of adding the water. Then, the Jew can continue by mixing with a shinui (מ''ב סי' שכ''ד סקי''א ).
Mixing Two Similar Things Together
36. Simply speaking, losh is mixing a liquid component with a solid component. The poskim discuss whether there is also an issur of losh when mixing two components of similar consistencies into one mass.
37. Butter with soft cheese. Some want to say one may not mix butter with soft cheese due to losh (חזו''א בס' דינים והנהגות לחזו''א פי''ג אות י''ב, הובא בארחות שבת פ''ו הע' כ', הגרשז''א הובא שם ).
38. However, most poskim allow this, as it is not losh; it is just mixing two things together. Thus, they allow mixing sour cream or leben with cottage cheese or another soft cheese, as well as honey with soft cheese or leben (אג''מ או''ח ח''ד לש סוף אות י''ג, חוט שני ח''א עמ' קי''ג אות ב').
39. Ketchup and mayonnaise. They also discuss whether one may mix ketchup with mayonnaise. Some hold these may not be mixed together in a thick mixture to become a new thing (הגריש''א, אשרי האיש או''ח ח''ב פכ''ט אות י''א ). However, most poskim allow it since they are both wet ingredients and thus not subject to the issur of losh (אבני ישפה ח''ו סי' ע''ג ענף ב', אחרונים ).
40. Chrain and mayonnaise [“chrainaise”]. Similarly, one may mix chrain with mayonnaise since they are both wet. Even though there are likely very small pieces of horseradish in the chrain, we view it as a wet ingredient, and it does not become a new mass together with the mayonnaise; it is just a new mixture (אבני ישפה שם ענף א', שבת במטבח עמ' קס''ג, ל''ט מלאכות עמ' תקל''ה ). According to the machmir opinion mentioned above, the mixing should be done with a shinui, e.g., in a crisscross pattern.
Halachos of Losh B’dieved
Intentional, Mistaken
41. If one violated losh on Shabbos, it is like he cooked on Shabbos – if he did it intentionally, the food is assur for him forever and for others until motzei Shabbos. If he did it mistakenly, it is assur for him and others until motzei Shabbos.
42. Gra’s opinion. The Gra has a well-known opinion that when it was done mistakenly, it is mutar for the person who did it and everyone else on Shabbos itself. In a situation of necessity, one may rely on the Gra’s opinion (מ''ב סי' שי''ח סק''ז ).
43. Chumra. In cases where, according to the main halacha, there is no issur of losh, but we are careful as a chumra, the food does not become assur b’dieved. Thus, one must know what is assur according to halacha and what is assur just as a chumra so that he knows what to do if losh was mistakenly violated.
חיזוק בענין לימוד הלכות שבת
אי אפשר כלל במציאות שינצל מאיסור שבת אם לא ילמוד כל הדינים על בריים היטב היטב (יערות דבש)
וראוי ונכון לכל ירא וחרד לדבר ה' לכונן חבורות ללמוד הלכות שבת כדי שלא יכשלו בם (מ''ב הקדמה ח''ג)
