how serious of a sin is it to break the kosher laws?
Well, there are different aspects to the laws of Kashrut. Some of those aspects would make a person liable to the penalty called “Kares” in Hebrew (roughly meaning “cutting off of the soul”), and others would make a person liable merely to be whipped with lashes. (Of course, that penalty can only be administered by a properly ordained Rabbinical court, which we do not have in modern times.)
In the “Kares” category would be eating blood, forbidden fats, or leavened foods on Passover.
All other laws of Kosher, such as forbidden animals (e.g., pork, shellfish), milk and meat cooked together, or improperly slaughtered animals would be in the “lashes” category.
I should mention that that “lashes” category is the lowest level of severity of punishment in Torah law.
cmkeller is saying correct things, but I believe you are painting an incorrect picture for the captain. There are different levels of kosher laws and there are different levels of breaking laws (levels of intent, etc.) The punishments of the courts mentioned by cmkeller do not apply today, but the seriousness of breaking any Jewish law is still applicable. In addition, to receive such punishments that cmkeller describes requires many variables, a proper warning, witnesses, an intent to violate the law, just to name a few.
There are even times when one is required to break kosher laws, such as illness, starvation or if forced by someone else with a threat of serious bodily harm.
The rules of halacha (Jewish law) are quite complex and it is hard to answer your question properly “on one foot” The more you delve into learning the Torah from its original sources, the more you will appreciate your own question and the more you will understand the beauty in the complexity of the answer.
If you have a more specific question on the specific circumstances that you are involved in I would gladly try to help.
Don’t forget to make the proper bracha (blessing) before and after eating
Have a happy and kosher Passover
The short answer to your question is that it is serious. One who is required to keep kosher should not lightly violate those laws. Of course, one can (and in fact must) do so when required to save his/her life.
There is some “behind-the-scenes” differences between different types of forbidden foods (blood vs. pork [different punishments] or shellfish vs. milk/meat mixtures [the former you can own and use but not eat, the latter is forbidden for all benefit]), but from a practical standpoint, short of a life threatening situation, one should not violate these laws.
Was there a particular reason you wanted to know? Did you have a more specific follow-up question?
(By the way, welcome to the boards ysmz613 and captainQwark)
Zev Steinhardt
I’m not Jewish, but for a year I cooked for a family who kept a kosher kitchen. Notice I did not say they kept kosher; only their kitchen. THis means that they followed the rules “religiously” in their kitchen, and when their parents were there, but that when eating out, or eating takeout on paper plates, they broke some of the rules. Also, the husband was something of a scholar. Anyway, my point in all this is that between discussions with the husband about certain kosher laws, and learning which rules were “breakable,” and to what extent and in what situation, I learned I think a lot about practical kashrut.
To wit, for example: the proscription against the milk-meat mixture was to avoid the abomination of cooking a kid (read: baby goat) in its mother’s milk. All subsequent changes to that law were to avoid possible confusion, and to make SURE that such a thing never happened. I.e., you can’t even cook lamb in cow’s milk, even though it doesn’t go against the intention of the original law, because if they allowed that, then some people would possibly become confused, or lax, and end up . . . cooking a kid in its mother’s milk. So why is it OK to cook eggs and chicken meat together? Nobody knows.
Anyway, since his dad came from a long line of Rabbis, and they sometimes had a Rabbi or two over for dinner, they kept two sets of dishes, and I always cooked accordingly. If they ordered in pizza with pastrami, we ate on paper plates and threw everything away; ditto cheeseburgers and shellfish.
Her dad paid a TON of money to kosherize the kitchen of the huge, worldclass hotel where they held their wedding reception.
**
I’m afraid you may have misunderstood or gotten some wrong information.
There are prohibitions that are mi’d’orissa (an Aramaic term meaning “from the Torah”) and then there are those that are m
d’rabbanan (from the Rabbis).
All meat (not fowl)/milk prohibitions are mi’d’orissa. True, the Torah only explicitly mentions milk/meat in the “kid in it’s mother milk” context. It is repeated so three times. However, following a universally applied precept in the Talmud that there are no extra words/sentences in the Torah, the oral tradition states that this applies to all milk/meat mixtures. Thus having a kid-boiled-in-it’s-mother’s-milk stew is just as bad as having a cheeseburger. No difference – they carry the same weight.
Fowl, OTOH, is not considered meat according to the Torah. However, because fowl meat has a similar consistency to real meat, the Rabbis applied a decree against the eating of fowl/milk mixtures, lest one come to also violate the milk/meat mixture.
The reason why eggs and chicken are OK is because there was no fear that if one allowed an egg/milk mixture that one would come to mistakenly allow a milk/meat mixture. The cases are not similar enough. For the same reason, fish/milk mixtures are OK because fish “meat” is sufficiently different in texture/taste/etc. from real meat that confusion would not be an issue.
In any event, from a practical standpoint, one must observe both laws that are m’d’orissa and m’d’rabban. The only practical difference between the two comes in cases of doubtful status (i.e. you have a food and are not sure if it’s kosher). If the doubt is regarding a Toratic (m’d’orissa) prohibition, one must rule more strictly, whereas in cases of doubt regarding a Rabbinic ruling, one may rule leniently. But aside from that, one may not violate a Rabbinic ruling. IOW, one may not eat chicken and milk and say to himself “I know the difference and will never come to eat real meat and milk together.”
So, in short, none of the rules of kashrus are “breakable.”
**
I would venture to guess that if they ate non-kosher out of the home, they weren’t too well informed as to the rules of kashurs, or simply didn’t care enough to keep them.
(As a side note: I will never, for the life of me, figure out the rationale of people who keep a “kosher home” but yet go out and eat non-kosher. And keep in mind that I grew up in such a home…)
Is it possible that they had people attending who would only eat kosher and did it for them?
Zev Steinhardt
So, then, a cheese-stuffed all-pork hotdog with clam juice ketchup would be right off the table.
Well, technically speaking, milk/meat mixtures only apply to kosher animals. Thus pork/milk is no more forbidden than pork by itself.
Now, if you wanted to make that a cheese-stuffed, pork and beef hotdog with clam joice ketchup, then you’re completely out of the ballpark. 
One more minor clarification on something I said earlier: Even though I cannot understand the rationale of those who keep kosher in the home, but not outside of it, I am not advocating that they abandon keeping kosher in the home. Better that they observe kashrus at least part of the way rather than not at all.
Zev Steinhardt
I think it’s probably that they think, “Keeping kosher is a Jewish tradition and helps define me as a Jew, so I’m going to keep kosher, but it’s also a silly tradition that doesn’t make any sense today, so I’m not going to go overboard doing it, like going out of my way to only eat at kosher restaurants or something”
Would eating food sacrificed to an idol also be in this category? I realize that it’s probably not much of an issue any more, but it seems to me like that would be a Big One.
And while we’re at it on the hot dog, throw in some insect parts, and put it in a bun on Passover :).
No. The first mishna in Tractate K’risos lists the 36 offenses for which one is liable to the punishment of kares. Worshipping an idol is one of them. However, merely eating from such a sacrifice is not (although I’m sure it will not endear you to the One Above.)
Zev Steinhardt
Zev, are you kosher both at home and out? If so…how do you KNOW everything is being properly prepared? Also, aside from a deli, are there kosher restaurants? Please describe.
It’s amazing how Jewish praxis and philosophy seems to be mirrored by my own Church (Orthodox). You’d think there was some kind of connection…
Yes, I keep kosher in home and out.
You can ask one better. I’m not usually at home when my wife prepares dinner. How do I know that she bought kosher meat, didn’t mix milk in it without my knowing, etc.?
The answer is based on a rule in the Talmud called eid echad ne’eman b’isurin (“one witness is believed with regard to [general] prohibitions.”) Thus, if my wife tells me that she prepared the food kosher, and I trust that she is familiar enough with the laws of kashrus to make such a statement, then I can believe her and eat her cooking even though I did not personally see that she prepared it the proper way.
There are kosher certification agencies, whose job it is to inspect foods and resturaunts and determine that they are being produced according to Jewish law. The most famous of these agencies in North America is the OU (Union of Orthodox Rabbis). They send out rabbis to different manufacturing plants and resturaunts and certify that the food being prepared meets the requirements of kashrus.
There are many different kinds of kosher resturaunts. Of course, they tend to congregate around areas where there are Orthodox Jews. Here in Brooklyn, there are many different types of kosher resturaunts, covering everything from pizza places to pasta bars to steakhouses to sushi joints to Tex-Mex to Chinese to…
Zev Steinhardt
Here are the restaurants in DC under the supervision of the Washington Vaad. They’re all kosher.
http://www.capitolk.org/supervised/restaurants.html
L’Etoile, a French restaurant which I believe closed last year also was kosher (and incredibly expensive)
zev: I’d imagine that the family mentioned above keeps their home kitchen kashrut so that their observant parents/parents-in-law will dine there when visiting. That seems to be a pretty common rationale (sorry, anecdotal only).
I managed to resist asking if a ham and cheese sandwich would be worse if the pig had been strangled but it made me wonder if asking such angels-on-the-head-of-a-pin questions is a gentile thing. I’ve always been a natual devil’s advocate but I wonder if it was due to my brief Catholic education. Do you get wiseass rabble rousers in yeshiva? [George Carlin]Hey Rabbi, if G*d is almighty powerful can me make a rock so big he can’t lift it?[/GC]
Actually after reading your wise reply Zev I realize it’s more like the man about to be stoned for blasphemy in Life of Brian.
Man about to be stoned: Look, I don’t think it should be a sin, just for saying “Jehovah.”
Priest: You’re only making it worse for yourself!
Man: Making it worse? How can it be worse?!?! Jehovah! Jehovah! Jehovah!
You reach a point where there are no more degrees of “worse.”
I find Jewish law to be fascinating. I’m blown away by the number of rules you have to keep straight and follow.
These kosher restaurants…are they advertised as kosher, or is that just known amongst Jews?
What kind of fat is forbidden fat?
Is it expensive for a restaurant to be kosher? I would think they’d want to include the huge number of kosher people as their clientele, but is it financially do-able?
Which reminds me of a story.
An old man fell ill and it was determined that in order to remedy his illness he had to eat some pork. So (Jewish law being what it is – i.e. if your life is at steak, you are required to eat the pork) he resigned himself to having to do this. However, he made a request. He asked that the pig be properly slaughtered according to Jewish law. So, they took the pig to the shochet (slaughterer) who killed it properly.
After slaughter, the shochet started inspecting the organs of the pig*. During the inspection, they find some lesions on the lungs of the pig. So, they take the lungs to the rabbi to ask if this would affect the status of the animal. Well, the rabbi takes the lungs and looks at them, but doesn’t offer an opinion. Finally after a few minutes, they ask him “So, what’s your opinion?”
He replies to them “What do you want me to say? I can tell you whether or not the lesions would invalidate the slaughter. But ultimately, they are still the lungs of a pig and the animal is not kosher regardless.”
- After an animal is slaughtered, it’s organs are inspected for certain defects which, if found, would render the animal non-kosher. Certain leisons on the lungs are among those defects.
Zev Steinhardt
Is a kosher butcher allowed to butcher non-kosher animals? In real life?