Goal of the class

To provide a working framework for understanding the severity of machalos assuros and to introduce the issur meyuchad of basar b’chalav and its basic parameters

Machalos Assuros Background

Tamei Hamitzvos

We keep mitzvos because Hashem commanded us, but it is agreed upon that there are “tamei hamitzvosgleanings and tastes of appreciation and rationale behind these commandments that we can utilize to arouse and strengthen ourselves to keep them.

The Ta’am of Machalos Assuros

  • Rambam (Moreh Nevuchim) – all of the machalos assuros are unwholesome and unhealthy
  • Ramban, Akeidas Yitzchak, Abarbanel, etc– If so then non-Jews shouldn’t be healthy, they should have been warned, you leave torah to be defined by current health advice, plus there are many substances that are unhealthy and dangerous that the Torah doesn’t explicitly forbid

So what is the reason? Timtum Halev Gemara Yoma “V’nitmeisem bam” al tikrei ele V’nitamtem bam” that issur and specifically machalos assuros are “metamtem the lev (dulling of heart). This effects our spiritual reality and sets us at a total disadvantage in being able to serve Hashem properly. Certainly the issurim that are associated with the animal world have an additional dimension in that they have “nefesh” – spiritual identity, which when I consume it, in as much as this “identity in animal nature” is not conducive to Avodas Hashem it will disrupt and hinder my ability to do so. i.e. Simanei kashrus and tumah of species, blood – the essence of that physicality, gid hanasheh – the specific tumah of meshicah to tavos in a general sense. The principle is you are what you eat!

What are the Machalos Assuros?


  • Non-kosher species– animals, birds, fish, and crawlers
  • Situations even with kosher variety animals – neveilah [no shchitah], treifah [simanei trefus], blood, ever min hachai, gid hanasheh, chelev
  • Vegetation – tevel, orlah, chadash, yayin nesech
  • Forbidden combinations – basar b’chalav and kilayim


Gezeiros (to prevent coming to an issur d’orysa)

  • Chalav akum
  • Gvinas akum
  • Yayin shenagah bo nachri
  • Basar sh’nisaleim min ha’ayin

Takanos (to preserve jewish character and uniqueness)

  • Bishul akum
  • Pas akum
  • Stam yeinam
  • Sakanah

Understanding Basar B’chalav

Centrality of Basar B’chalav for us

Perhaps more than any of the other machalos assuros we must face and deal in our kitchens with the prohibition of basar b’chalav. With regards to the kosher variety species, most problems of blood, neveilah, treifah, ever min hachai, gid hanasheh, chelev, the vegetation issurim, the rabbinical prohibitions they are mainly dealt with by the various hechsherim. This underscores the need to have a good solid list of reliable hechsherim because there is really a lot at stake. Throughout the year we will isolate certain aspects of these other issurim that we do commonly run into in the home but again for us the main issue is basar b’chalav. Does everyone understand why?

Uniqueness of Basar B’chalav

First of all the unique concept behind “basar b’chalav” – Unlike all of the other issurei achilah in the Torah (except maybe kilayim) the prohibition of basar b’chalav is inherently from two ingredients that are both themselves kosher and edible when separate. Only when you fuse them together does the Torah forbid them. This is a chiddush which has many ramifications as we will see ahead. The main ramifications of this unique issur are:

  • Assur b’hana’ah – The Torah places an extra level of strictness on this issur because of its uniqueness
  • Shriyah is only assur d’rebanan – but mutar d’orysa because the tastes don’t fuse through bishul
  • Ta’am k’ikar – Since basar b’chalav fuses to make a new entity subsequently bitul is necessary on the entire entity not just the milk or meat volume.

What is the Torah Prohibition of Basar B’chalav

The Torah writes three times the prohibition of “lo sevashel g’di b’chalev imo”

  1. Issur bishul
  2. Issur achilah
  3. Issur hana’ah

What is the Rationale Behind Basar B’chalav

Although we generally relate to basar b’chalav as a chok, nevertheless the poskim did mention certain rationales that we can relate to.

  • Ancient avodah zora custom during worship (Rambam)
  • Not humane (Ibn Ezra)
  • Imbues cruel nature inside of a person
  • Ancient pagan fertilizer
  • Manipulating the spiritual forces in the briyah like kilaim (Sefer Hachinuch)

Issur Bishul

Which Type of Milk and Which Type of Meat?

  • Chalev Imo – really means any kosher variety domesticated animal milk
  • Gdi – really means any kosher variety domesticated animal meat

Derech bishul asrah Torah

With regards to the issur bishul – the gemara says “Derech bishul asrah torah” – this means only that which is specifically defined as “bishul” is included in the Torah prohibition.

What is Defined as Bishul?

Min HaTorah According to all Poskim

Broiling (cooking in a liquid including deep frying)

  • Kli Rishon – while on the fire d’orysa, off the fire but still yad soledes machlokes and therefore assur behana’ah unless there is a hefsed merubah
  • Irui Kli Rishon – this cooks a kdei klipah
  • Kli Sheni – doesn’t create issur hana’ah, but causes transfer of tastes and therefore assur to eat

Min HaTorah According to Some Poskim

  • Frying, Barbecuing, Roasting, Baking – these are cases of a machlokes and therefore assur behana’ah unless there is a hefsed merubah.
  • Hot springs, Sun cooking (also a microwave), Smoking – these are cases of doubt and therefore are assur lchatchilah min hatorah.

Only Assur M’derabanan

These are all mutar behana’ah bidieved since only derabanan

  • Negiyah (cham v’cham)
  • Salting
  • Soaking
  • Pickling

Previously Cooked Meat and Milk

The halacha is that these items are assur regardless of whether they were previously cooked when separate. This is true whether the milk was cooked previously, the meat was cooked previously, or both were cooked previously. Once they are cooked again together they make d’orysa basar b’chalav.

Cooking Inedible Meat and Milk

The poskim say that this is not under the principle of “derech bishul”. Since these items aren’t edible to begin with they aren’t considered items that are normally cooked.

How Cooked is Called Cooked?

Machal ben Drusoi – This means food that is at least 1/3rd cooked

Rabbincal Prohibitions Within the Issur Bishul


  • Chayah v’oif – Even though the Torah permits cooking milk with chayah v’oif, the rabbis prohibited it because of maris ayin. This issur includes an issur hana’ah.
  • Behemah temeyah – Some poskim hold that we don’t need a fence here since the meat is already assur to eat by itself. Other poskim hold that since the onlooker can’t tell the difference therefore the rabbis forbid this case as well because of maris ayin.
  • Dagim (with dairy) – Here there is no need for an issur of maris ayin. However some poskim hold that there is an issue of sakanah here and that this is forbidden both to cook and eat together. Most poskim are not choshesh for this and therefore it is mutar to both cook and eat fish and dairy together


  • Chalav temeyah – Same as above by behemah temeyah
  • Chalav em (mothers milk) – As far as the Torah is concerned this is not considered dairy. However the rabbis forbid this milk to be cooked together with meat. If however it falls in to a meat dish and is not “visible” it is mutar bidieved.
  • Artificial milk – The Rema says that the custom is that when you cook meat with this type of milk you need to place almonds next to the dish both when cooking and when serving to avoid maris ayin. Some add that this applies even with chicken. If this type of milk was not cooked together with meat but rather just mixed together or they are being eaten together then the following factors determine the halacha. If the milk is not visible it is permitted. If the milk is visible but it is in a private home some poskim permit this. There is a prevalent custom that when everyone has become familiarized with the use of this artificial milk substance in cooking and eating then the maris ayin no longer applies. For this reason today things like margarine, non dairy creamer, and pareve ice cream are eaten with meat and used in cooking since everyone knows that they are prevalent.

Issur Achilah

The issur achilah min hatorah applies to all forms of basar b’chalav that are assur min hatorah in the above section The rabbis forbade eating many other forms of basar b’chalav. The examples of basar b’chalav that are assur to cook are all assur to eat as well based on this prohibition.


Klal Yisrael is a holy nation. Even when the rabbis have not made decrees, they have accepted upon themselves to keep a higher standard in many areas of halacha in order to protect themselves from coming anywhere near transgressing the Torah laws. We will have a special shiur dedicated to the many customs that have become accepted in Klal Yisrael in order to avoid coming to any shaylah of basar b’chalav.

Issur Hana’ah


There are a few common forms of benefitting from basar b’chalav

  • Restaurant owner – Cooking in a kitchen for profit
  • Store – Selling to non-jews
  • Stocks – Depending on the exact nature of the investment and the type of legal structure the company has this can be a problem.

Feeding to pets

When buying pet food it is important to check for a hechsher. It is common for these products to contain meat and dairy together. Depending on the exact method of production there can be questions of an issur hana’ah based on what we learned above in the Issur Bishul.

Using a Non-Food Product

As a general rule non food products don’t pose a problem of basar b’chalav. The reason for this is that the tastes are usually ruined by the other ingredients and additives in these products. This is not under the heading of “derech bishul” or “derech achilah”. However the Rema brings that some kadmonim were machmir on this type of product. Therefore it is not uncommon to find hechsherim on many household products. Although one is not “obligated” to buy these products with a hechsher, it is important to realize why they are there. Also with regards to the issur of chametz there are much more severe issues which we must be concerned for and when purchasing for pesach one should actually buy the products with a hechsher.

Disposal of Basar B’chalav

  • Throwing away in the garbage can – This is a big shaylah one should avoid it.
  • Burning –  This is okay unless one is benefitting from the heat, light, or energy from the fire
  • Burying, Flushing in toilet, River without fish – These are preferred methods of discarding