Milk from non-kosher animals, such as camels, is not kosher, and looks relatively similar to milk from kosher milk. Because a non-Jew might mix some of the non-kosher milk into kosher milk, Chazal decreed that milk from a non-Jew (chalav akum) is forbidden unless a Jew was at the milking (chalav Yisroel) to be sure no non-kosher milk was added in.
Pri Chadash is of the opinion that if one lives in a country where people do not milk non-kosher animals or where that milk is much more expensive than the cow’s milk, we may drink milk even if it is not “chalav Yisroel”; Chazon Ish accepts this opinion. This would apply to fluid milk in countries like the United States where there is basically no non-kosher milk available, and surely not at prices that are competitive with cow’s milk. Chasam Sofer argues that chalav Yisroel is required even in such circumstances. Rav Moshe Feinstein said that even Chasam Sofer would agree that in the United States one can drink the standard milk (chalav stam) because the combination of government regulation and the company’s business interests provide adequate proof (anan sahadi) that the milk is actually from a cow, and such proof is as good as a Jew watching the milking. Many American Jews rely on Pri Chadash or Rav Feinstein, while others are particular to only drink the traditional chalav Yisroel where a Jew was at the milking.
The leniencies of Pri Chadash/Chazon Ish and Rav Feinstein are built on an understanding of the legalities, and farming and business practices of American dairy farmers. The same does not necessarily apply to the milk or other dairy products from different countries. Accordingly, someone eats chalav stam in the United States and will be travelling to a different country (such as the Caribbean or China), or who is Mashgiach in a facility which is receiving dairy products from a foreign country (such as India), should check whether chalav stam actually is permitted in those places.
There are some people who are particular to only drink chalav Yisroel milk, but will nonetheless use certain dairy products which are chalav stam. Different variations of this practice include people who are lenient about powdered milk, acid casein, butter, lactose, and/or cheese made from chalav stam milk. Before relying on one of these leniencies, one should discuss the issue with their Rabbi and with a kashrus professional (to understand which items contain which ingredients).
Shulchan Aruch says that if utensils were used with chalav akum, the utensils must be kashered before they are used for kosher milk. Some people who only eat chalav Yisroel, particularly Chassidim, take that halacha at face value, and will not eat any food made on chalav stam equipment (unless it was kashered first); they would not eat food labeled “DE”. Others, will only eat chalav Yisroel, but are not particular about eating food made on chalav stam equipment. [In other words, they consider it a mere chumrah to not eat chalav stam, and are therefore just careful about actual chalav stam but are lenient about chalav stam utensils.]
A person who is the Mashgiach at a chalav Yisroel milking, must (a) check that the tanks, equipment, and tankers which will hold the milk, are empty before milking begins, (b) see that the only animals in the herd to be milked are cows (or another kosher animal), (c) be yotzeh v’nichnas during the milking, and (d) seal all of the chalav Yisroel tanks or tankers once they are filled. In addition, (e) he must kasher any equipment which is used “hot”, such as a pasteurizer, or in which the milk sits for 24 hours (kovush), and (f) any cows which had surgery to repair a displaced abomasum must be removed from the herd (more on that in a future unit).
Milk contains fat, protein (casein & whey), sugar/lactose, water, and some minor components. If the fat is removed from milk, it can be sold as “sweet cream” or “whipping cream”, and does not pose any significant kashrus issue. Butter is made by whipping and churning cream. High-quality butter is made from “sweet cream” but it tastes so plain and pure that some companies add lipase or starter distillate (both, kosher-sensitive ingredients) to make it taste like what people expect butter to taste like. Butter can also be made from “whey cream”, which is a cheese by-product, and whey-cream itself is kosher-sensitive. Because of these concerns, butter requires hashgachah.
The term “buttermilk” has two different meanings. When sold commercially, it refers to the milk-like liquid leftover from the production of butter. The buttermilk sold in retail stores is something very different; it is not made from butter at all and is cultured skim milk mixed with other kosher-sensitive ingredients. Both forms of buttermilk require hashgachah.
If the casein-protein is removed from the milk, it creates “cheese”, and there are two basic ways to get the casein out of the milk. If the casein is separated using rennet, it creates hard-cheeses like cheddar or mozzarella cheese. To make those cheeses kosher, not only must the rennet be kosher, but a Jewish person must participate in the cheese-making so that it is gevinas Yisroel. The other way to separate the casein is with vinegar, lemon juice, or some other “acid”. This creates soft cheeses such as cottage cheese or farmer cheese. All of these cheeses are only kosher if they bear reliable hashgachah.
After the casein is removed from milk to create cheese, the leftover liquid is called “whey”. It can be used to create whey protein powder, whey cream, and ricotta cheese.
Milk can also be “soured” in a way that causes all of the milk to solidify into yogurt or sour cream. These are not “cheeses”, since the casein remains mixed in with the other parts of the milk. Ice cream is another food made from the entire milk, with extra cream added. Due to the ingredients added to these products they all require hashgachah.
After all the cheese and whey-products have been “squeezed” out of the milk, it is still possible to extract lactose (milk sugar) from the leftover water. In turn, that lactose can be used as a plain ingredient (such as in homeopathic melting tablets) and can also be fermented into alcohol. An example of this is Vermont Spirits’ white vodka which is made by fermenting lactose. Not only are these items dairy, but they require hashgachah to ensure that they whey they are made from was kosher.
Hard cheese, such as mozzarella and cheddar, is created by adding rennet into milk, which causes the curd (casein protein and some fat) to separate from the rest of the milk. This type of cheese is only kosher if it is “gevinas Yisroel”. Rema states that gevinas Yisroel is created when a Jew is present during the cheese-making to ensure that no (non-kosher) animal rennet is used. Shach argues that gevinas Yisroel requires either that the Jew own the milk/cheese or that he participate in the cheese-making by putting the rennet into the vat.
For decades, hashgachos in the United States insisted that cheese is only gevinas Yisroel if one follows the strict opinion of Shach that a Jew must put the rennet into the vat. The cRc and certain other hashgachos continue to maintain this position. However, two large and well-known hashgachos have allowed cheese to be labeled as kosher if the Mashgiach merely stands by to watch the cheese-making even if he does not actually put the rennet into the vat. [They do this to allow cheese-making on Shabbos when it is forbidden for a Jew to put the rennet in.] Rav Schwartz has directed us to accept those cheeses as kosher (as there is reasonable basis for their position) but not to adopt this leniency in our own cheese-making facilities.
Cheese which is not gevinas Yisroel is referred to as “gevinas akum”, and if it was used on kosher equipment, that equipment must be kashered. For example, if non-kosher cheese was used in a pizza oven, that oven must be kashered before it can be used for kosher food.
The basic requirement to create kosher cheese is for it to be gevinas Yisroel. In addition one would have to be concerned with the following equipment issues: whey-draining tables (if over yad soledes bo), reusable cheese cloths, brine tanks, cooking equipment for mozzarella or ‘American’ cheese, smoking equipment, and wire-cutters used for slicing.
Even if a cheese is not gevinas Yisroel, the whey leftover from the cheese-making is still kosher unless any one of the following three things occurs: (1) the cheese was made with animal rennet, (2) the cheese was made at above yad soledes bo – 120 F), or (3) the company mixes mozzarella cook-water (used to stretch the mozzarella cheese) into their whey.
Gevinas Yisroel is only required for hard cheeses (and rennet casein, which is essentially fat-free hard cheese) but not for soft cheeses, such as cottage cheese, and not for other dairy products such as butter, ice cream, ricotta cheese, yogurt, sour cream, lactose, or acid casein.