The Questions (and Answers) of BDJ

 View a printable version of this Q & A here.

Q: What’s the deal with heating food up on Shabbos? Sometimes I see people use their ovens on Shabbat mode, other times people use a hot plate. Is there a reason?

A: (RYK) To begin, it’s important to note that “Shabbat Mode” is a slight misnomer. This is true in two senses: (1) It does not at all mean that we have carte blanche on Shabbat to place foods into an oven simply because it is set on Shabbat mode. The standard halachot of cooking and warming food on Shabbat are still in play. And (2), one of the coolest Shabat mode features (the delay between when you adjust the temperature and when that change actually kicks in) is only relevant on Yom Tov, when cooking is permissible. You can find basic information about what Shabbat mode and what is does here.

Directly to your question now: On Friday afternoon we may place our already fully cooked foods into an oven that is no longer on but is still hot, so that the food will be nice and warm when the Shabbat meal begins. The Shabbat mode prevents any lights or other electronics from being triggered when we open the oven door at mealtime.

When we want to warm (already fully cooked) food on Shabbat day, an oven does us very little good. This is because when we warm food on Shabbat itself we are required to avoid what the Talmud calls “the appearance of cooking”. Most halachic authorities (with exceptions, I should note) regard the placing of food into an oven on Shabbat as the very epitome of “the appearance of cooking”. This is why we look to warm the food in a manner that is distinctly different from the way we cook food. What makes a hot plate so useful here is that nobody cooks on a hot plate. According to numerous Halachik authorities the same is true regarding a blech that is on top of the stove (though more typical Ashke-normative practice is to also place an inverted pan on top of the blech and to place the food to be warmed on top of the inverted pan, just to be super sure that we are avoiding the appearance of cooking.) People will also place food on top of their urns to warm, again because nobody cooks this way.

Q: Can you cut/tear foil/plastic to wrap up shabbat leftovers?

(This response originally appeared in our Q and A of 6/28/24)

A: (RYK) On Shabbat, we refrain from creative physical activity. The reason we do not tear paper towels, aluminum foil, and the like is that if the towel or foil is still attached to the larger roll, its utility is limited to non-existent. When we tear it off the roll, we are creating a useful object that had not existed before. The relevant melacha (forbidden activity) here is less the melacha of “tearing”, and more the melachot associated with “building”. Part of Shabbat preparation (an important Mitzvah in its own right) is preparing the paper towels and foil that we anticipate we will need.

Toilet paper follows the same logic, and also should be prepared before Shabbat (who remembers the Srugim episode that highlighted this 🙂?) The big difference when it comes to toilet paper is that the Halachik concern for human dignity (kavod habriyot) waves rabbinic prohibitions, including the “tearing / building” of an object when that object is designed to be non-permanent (i.e. all of the things we are discussing here). The Gemara cites the case of a person who on Shabbat has nothing with which to wipe himself, as an example. In practical terms then, if you find yourself on Shabbat in a sticky situation of this nature, you should most definitely tear some toilet paper. If possible, avoid the tearing on the perforations, as in this way you are not “building” a perfectly formed object.

As a final note, tearing open a package for the purpose of accessing food on Shabbat is expressly permitted (and there is more to be said about this if anyone would like to ask a follow-up question 😀)

Q: I’ve had difficulty in understanding halachic rulings made for the purpose of keeping the “spirit of Shabbat”. The “spirit of Shabbat” feels quite vague of an explanation and could be interpreted and stretched pretty far in both directions when it comes to stringent or lenient rulings. Are these rulings actually considered “halachic prohibition” vs a “fail safe”? For example, the prohibition of swimming in a pool on Shabbat. From what I understand, it’s not permitted because someone might build a raft or wring out clothes. If I were to make sure neither of those happen, some would say it still violates the “spirit of Shabbat” and therefore not halachically acceptable. Is this true? Same question with the use of electrical devices that have been turned on prior to Shabbat (phone/TV/laptop, etc). What does the “spirit of Shabbat” actually cover when these decisions/rulings are made?

 (Some of this response originally appeared in our Q and A of 6/28/24)

A: (RYK) The admittedly ambiguous concept of the “Spirit of Shabbat” is somewhat more concretely referred to in the Talmud as “uvda d’chol” (deeds of the work week). The Talmud’s idea is that there are certain activities which, though they are technically permissible on Shabbat, seriously compromise Shabbat’s quality as a day palpably set off from the other six days of the week. In truth, I believe that “uvda d’chol” may be the most important Shabbat category we have in modern times, for two reasons:

1. We moderns do very little leather-tanning, sheep-shearing, or weaving these days, and we thus happen to refrain from most of the 39 melachot Sunday-Friday as well. We are therefore even more in need than our ancestors were of consciously setting Shabbat apart from the weekdays.
2. Were it not for the prohibition of engaging in “uvda d’chol” there would Halachikly be little-to-nothing standing between us and using our computers and phones on Shabbat, which is to say engaging in what is for many of us, our primary mode of work!

It is true that outside of the Talmud’s concrete examples of “uvda d’chol” it is difficult to determine with precision what falls within the category. And it is also true that the category can shift over time. (When I was growing up, riding a scooter would certainly have been included in it! Today, not so much.) Yet what it lacks in crispness and rigor, it more than makes up for in its centrality and urgency, especially in contemporary times. I think that watching TV for example, is unambiguously “uvda d’chol” in that it whisks us instantly out of our Shabbat communal / spiritual headspace, right back into the world that we occupy Sunday - Friday.

The swimming question is a little more complex, but not ultimately different. The Mishna prohibits swimming in open bodies of water lest one fashion a flotation device. This concern does not apply when swimming in a body of water “that has a lip around it”, such as a pool. In addition, another concern expressed in the Gemara, that one might splash water a distance greater than 4 amot in a public domain is obviated in a gated backyard or in a place that has an eruv. (Other concerns have been raised, such as the possibility that the swimmer will wring out the bathing suit afterwards, but one can simply be sure to avoid doing this). So technically, swimming in a pool is permissible on Shabbat, and as I’ll mention at the bottom, sometimes it is practically so as well.

Again though - and here I am also echoing a great deal of contemporary Halachik opinion - the question is how this will impact our Shabbat “state of mind / state of soul”. In order to swim we obviously need to remove our Shabbat clothing (which we may feel unmoved to put back on in order to appropriately fulfill the mitzvot of Shabbat Mincha and Seudah Shlishit), and we invariably plunge ourselves into the gestalt of a recreational activity that makes Shabbat afternoon indistinguishable from Sunday afternoon. One can reasonably make exceptions on a particularly hot day for children to swim and for adults to put their feet in the water. And such an exception would be a “teachable moment” for our children, about how we are careful to take special care of the fragile gift that is Shabbat by not engaging in the “ordinary” recreational activity of swimming, and only making an exception when our “Oneg Shabbat” (the mitzvah to enjoy Shabbat) is being undermined because the heat is making us truly uncomfortable.

Q: I have heard different things about how we are meant to access our hotel rooms (with electronic locks) on Shabbat. Some of the “greatest hits” include taping the lock so that it doesn’t engage, asking the front desk to have someone open the door for you, or using a shinui to open it yourself. What are the circumstances, if any, where it’s okay for us to open the door ourselves?

A: (RYK) Much of the contemporary Halachik discussion about electricity regards the use of electricity (as long as it doesn’t involve an incandescent light) as coming under the above-mentioned uvda d’chol (“weekday deeds”) category. While this obviously does render the use of electricity forbidden on Shabbat, this categorization of electricity use allows us to apply to it the leniencies that we routinely apply to rabbinic (as opposed to Biblical) prohibitions, and opens other possibilities for leniency as well.

So to begin then, it is certainly preferable to avoid using electricity to open hotel doors on Shabbat. Whether or not this is practically feasible is of course a different question. When it isn’t, here are the ways that we can go.

1. It is permissible on Shabbat to ask a non-Jewish friend (asking is a rabbinic prohibition) to perform something that is itself a rabbinically forbidden act, when this will enable us to perform a Mitzvah. So we can certainly ask a non-Jewish employee to open the door for us (or push the elevator button for us if we cannot physically climb the stairs) when we need to access the Shabbat food that is in our room or to access other items (such as the beds) that will enhance our oneg Shabbat. 
2. Rabbi Dov Linzer has written in numerous contexts that when it comes to the “uvda d’chol” category and the use of electricity, much depends on the extent to which we are actually experiencing the use of electricity. In the case of the hotel room door, he advises that before Shabbat we cover the small LED light that goes on when we insert the keycard, so that we have no experience of seeing it illuminate. And that with regard to the actual unlocking of the door he advises that we insert the keycard in a deliberately unusual way (the use of a shinuy), such as using the opposite hand than the one we’d habitually use. The use of the shinuy to activate electricity puts it in the same halachic situation discussed in (1), namely the performance of a rabbinically forbidden act in a way that is itself only rabbinically forbidden, all for the sake of a Mitzvah.

The late Rabbi Nachum Rabinovitch zt”l went further still, ruling that any act that we typically perform mechanically (such as the unlocking of a door or the turning on of a sink) is simply free of “uvda d’chol” considerations even when this act is done electronically. I don’t think that this is an accepted position by and large, but it is interesting to note.

Q: Can you brush a dog’s hair on Shabbat? I have found this is a lovely way of bonding with our pet and our family, and we often have time to do so on Shabbat. It relaxes all of us and our dog. But is it violating Halachic melacha to do so?

A: (RYK) The answer depends upon what typically happens when you brush your dog’s hair. If the brushing typically (even if not 100% of the time) pulls out loose hairs, then you’d have to assume that this is what will happen on Shabbat as well. Brushing or combing that typically pulls out loose hairs (whether canine or human) ultimately falls under the melacha category of “shearing”. I say “ultimately” because even though it is not our explicit intention to pull out hairs, the facts that (a) it will typically happen and (b) we regard the removal of loose hairs as being a good thing, render the act of brushing as functionally the same as the intentional removal of hair (i.e. shearing). 

An option that pertains to human hair and would equally pertain to dog hair, is to use a particularly soft brush that you’ve verified before shabbat typically does NOT remove hair.

(There is a debate among halachic authorities whether or not pets are considered muktzah. Interesting material on this can be found here and here)

Q: I noticed in Shul that we only have instant coffee on Shabbat, and it got me thinking. Do we have other options? I've heard that using a french press can be problematic unless one doesn't push the plunger down all the way - is this true? Or is the only acceptable method doing a pour-over?

A: (RYK) Thank you to the two people who asked this question!

So, from someone who never arrives at shul without having had a good cup of coffee….  Making fresh coffee using a pour-over is halachically wonderful. Here’s how: (1) While it is true that taking a mixture of coffee grounds and water and pouring that mixture through a filter is forbidden (because you are using the filter to separate the water / coffee from the grounds, which violates the prohibition of borer), to pour water onto coffee grounds in such a way that the water then continues down into your coffee mug is not defined as an act of “separating a mixture” at all. (2) The only halachic precaution that needs to be taken is to use a kli sheni when pouring the hot water onto the grounds. While there are Halachists who argue that the category of “cooking” does not apply to foods that had previously been roasted (e.g. coffee beans), there are others who disagree with this assertion and require us to treat such foods in the same way that we’d treat raw foods. The pouring from a kli sheni addresses this concern. 

The French Press however, does present a borer issue, as the plunging of the water + coffee grounds mixture for the purpose of pushing the coffee grounds out of your coffee, does constitute borer. (I have seen the argument that if one doesn’t plunge all the way to the bottom thus leaving some of the mixture intact, the act of borer is avoided, but this argument has never made any sense to me, and I just don't think it’s right.) It’s important to note, that a French Press CAN be used on Yom Tov, when the prohibition of borer is considerably narrower.

Q: Is one allowed to use glowsticks on Shabbos?

A: (RYK) I'd like to research this more, but here's an interesting site to look at meanwhile!

Q: Are the rules of what you can drink for your Kiddush Friday night, Shabbat morning, and havdallah Saturday night different? I believe all alcohol works, but I know for some things it can be the "drink of the land," but I would love clarification on each option. Plus, can you really use challah instead?

A: (RYK) There’s much discussion, from the Talmud on down, about using beverages other than wine for Kiddush. The undebated premise of the discussion is that wine is the optimal choice, as this most honors the mitzvah of Kiddush. The question arises though as to what to do if wine is not readily available in a given locale. One group of rishonim holds that bread is the only other acceptable alternative to wine in these circumstances. Another group holds that the best alternative to wine are beverages that function as the social equivalent to wine in that locale, beverages such as beer. The Shulchan Aruch cites both opinions and then seems to ultimately favor a hybrid position taken by Rabbenu Asher (Rosh), who prefers the bread option on Friday night, and the “other beverages” option on Shabbat day. The reason for not going with the bread on Shabbat day is that formally speaking the entire content of the Shabbat day kiddush IS the bracha over the wine. If this bracha is instead said over bread, how would one recognize this as “kiddush” at all (s opposed to it simply being the “ha-motzi” with which we always opens the meal)? Thus, the preference for using an alternative beverage. Rama explicitly endorses this position. Again, this is all assuming that wine cannot be readily found.

Interestingly, the historical record is clear that “other beverages” are used for Shabbat day kiddush even when wine is plentiful in a given locale. While there is much speculation as to how this development came about (and certainly the fact that Shabbat day kiddush is not a Biblical mitzvah but a rabbinic one has something to do with it), it has clearly found its Halachik acceptance within our Kiddush tradition. When using liquor for Shabbat day Kiddush, it is important to not use a shot glass, rather a standard-size kiddush cup, and to drink the same 1.7 oz. or so that is the minimum when we say Kiddush over wine.

Havdalah is a different story, where there is wider agreement that beverages other than wine may be used, though many authorities including Rama still maintain that wine is the most preferred.

A final word about what beverages qualify as “other beverages” in this context. The main criterion is that these beverages are drunk when people meet socially. This is presumed to include all alcoholic beverages, and quite possibly also things like freshly brewed coffee.

Q: Near the south pole, why does Shabbat end way over 60 minutes after it began?

A: (RYK) It’s all about latitude.

The calculation of how long after sunset we end Shabbat goes as follows:

1. We first must wait until the end of “beyn hashmashot”, the Halachik twilight. This twilight period ends when three medium stars appear in the (non-ambiently lit) sky.
2. We are stringent when it comes to ending Shabbat to actually wait for the appearance of three small stars, as “medium” is a subjective term, subject to misidentification.
3. In addition, as our way of fulfilling the mitzva of “adding to Shabbat”, we wait a little more time until there would be three small stars close to one another in the sky, as opposed to being spread out. This is how we arrive at our published “Havdalah time”.

Latitude significantly impacts step (1). It is understood that the Talmud’s calculation of Halachik twilight (about 13 and ½ minutes) is specific to the latitude of Babylonia. The farther north or south we go, the longer that period becomes, pushing the rest of the calculation out further as well.