Oregon Kosher
An in depth look at the laws of
kashrus as they pertain to cheese
© 2014 Oregon Kosher
We are going to begin by
defining some items used in
the cheese making process
that we will need to be
familiar with to understand
this class.
As its name implies, the starter culture is the first ingredient added to pasteurized
milk to make cheese. Milk is pumped into a cook vat where starter culture
containing specific bacteria are added. That bacteria forms acids in the milk,
lowering the PH to a critical acidity level. It causes the lactose in the milk to turn
to lactic acid. It is the culture which gives different cheeses their special
characteristics. If the specific temperature is not maintained, the bacteria in the
starter culture fail to multiply and the cheese process could not continue. Starter
culture certainly needs to be kosher, and some agencies require that , as a
coagulant, it needs to be put into the cook vat by a mashgiach for reasons we will
discuss.
Rennet
Rennet will be the single most discussed ingredient we will deal with. First let us
define what it is, and then we will discuss what it does, after which, we will discuss
why it is such a halachically sensitive ingredient. There are two types of rennet,
animal rennet and microbial rennet. Animal rennet is a complex of enzymes
produced in the abomasum of a calf. The abomasum, pictured below, is the fourth
stomach of a calf. These enzymes are only produced in the abomasum of a calf, and
are used as the main ingredient to coagulate milk into curds which eventually form
cheese. In earlier generations, cheese making involved putting a piece of an
abomasum or the scummy contents of an abomasum into milk to cause it to
coagulate. Nowadays, rennet can be extracted from the glands of the abomasum.
Rennet
The second type of rennet, microbial rennet, is widely used today in cheese productions.
This rennet is produced by growing the protein on microorganisms. These rennets are
readily available with reliable kosher certification, and can cause the same coagulating
effect as animal rennet when added to milk. In my experience, many more cheese
factories use microbial rennet than animal based rennet today, although animal rennet
is used in more expensive artisan cheeses. It should be noted that the bulk of today’s
cheese manufactured in mainland Europe does contain animal rennet. Furthermore,
lipase—an enzyme added to some cheeses to hasten the breakdown of fat and endow a
more powerful flavor—is almost always animal-derived (lipase is extracted from the
tongues of domesticated animals), although artificial lipase substitutes are becoming
more widespread. Romano cheese is usually treated with goat, lamb or kid lipase, and
blue cheese often contains calf lipase.
Rennet
Before we get into our sources for this evening, it is important to know that all
ingredients going into cheese would need to be kosher; therefore, producing cheese
with rennet from a calf that was not properly slaughtered in accordance with halacha
would render the cheese non kosher. Animal rennet and lipase can be kosher,
however. If the kosher source animal is slaughtered, de-veined, salted and processed
according to kosher law, its rennet and lipase are fine for kosher use. (There is no
halachic problem with using animal-derived enzymes in cheese [mixing meat and
milk] since the amounts used are miniscule. Moreover, the enzymes are not cooked
with the milk, and they are flavorless. Still, even cheese made with glatt kosher animal
rennet and lipase is forbidden when manufactured by non-Jews, which will be the
main discussion of our class.
Curds
The rennet that allows the milk to coagulate and set. The coagulated milk is
formed into a smooth, custard-like solid called the curd. Finally, the curd is
ready to be cut which means that the cheesemaker breaks up the curd,
separating a rich, cloudy liquid from the solid pebble-like curds. The liquid
cloudy water is known as whey, and the pebble-like curds is the basis of the
cheese.
Whey
Whey is the basic by-product of cheese manufacturing. It is the portion of the milk
that did not precipitate out of the milk and form cheese curds. The milk’s casein
protein and much of its fat exit the milk and become curds. The remaining milk
material, no longer white and thinner, is whey. Liquid whey is rich in protein,
lactose and minerals. Whey's functionality has only been realized in the past 25
years. But general use of nisyovay d'chalvah, whey, has been known for thousands of
years and is mentioned in the Talmud.
Whey
There are many products made from whey. Often, liquid whey is used in making
Ricotta cheese. The process includes cooking liquid whey at very high temperatures
with live steam. An acid, usually acetic acid or vinegar, is added, resulting in a
curded ricotta cheese. Some companies substitute milk instead of whey to make the
ricotta. Whey is also used to create whey cream butter. Like whole milk, whole liquid
whey can be separated into sweet whey and whey cream. The whey cream can be
added to regular milk cream and be churned into butter or the whey alone can be
churned into whey cream butter. Just like kosher whey, kosher whey cream butter
would be acceptable. One of the most prevalent whey products is powdered whey.
Through a water filtration process known as osmosis, whole liquid whey can be
separated into its basic components, i.e., whey protein and lactose. Today, whey
protein and lactose are used for a host of food applications. However, it is impractical
to use them in their liquid form. When used as food ingredients, they are dried into a
powder. A popular technology used to dry these ingredients is known as spray
drying.
Casein and Caseinates
Casein is the main protein found in milk and subsequently found in the cheese
curds. Casein is used in a plethora of food applications, and defines cheeses that are
used as an ingredient in industrial applications. It can be used as an emulsifier in
coffee whiteners, a stabilizer in ice cream or a thickener in soups, gravies, or whipped
toppings. It can also be used to provide texture to pasta, nutritional food bars or
bakery products. Casein, like cheese can be created by adding either rennet or acid to
milk to cause it to coagulate. Acid based casein can undergo further processing to
create other casein products known as caseinates. Caseinates are used in other food
ingredient applications. When the wet casein is mixed with sodium hydroxide, the
resulting product is known as sodium caseinate. This is a popular ingredient which,
among other things, may be used as an emulsifier in coffee whiteners, a nutritional
ingredient in bakery products, nutritional food bars and beverages, as well as a
thickener in soups and gravies. Casein can also be combined with calcium (lime) to
create calcium caseinate, an ingredient in cereals such as Special K.
Rennet Based Cheese Vs Acid
Based Cheese
There are two main methods for curdling cheese. The first is adding animal or microbial
rennet to coagulate the milk. Rennet based cheeses form more solid curds that can be
easily separated from whey. The second method of creating cheese involves adding
acidic bacterial cultures to cheese to cause it to coagulate. The resultant cheese curds are
softer and are harder to separate from the whey. Often, a small amount of rennet is also
used in creating acid based cheese. Rennet based cheese is often referred to as hard
cheese while acid based cheeses are referred to as soft cheeses. Rennet based cheeses
include cheddar, mozzarella, provolone, and hundreds of others. Acid based cheeses
include cream cheese, cottage cheese, and farmers cheese.
Review
Starter Culture- first ingredient added to pasteurized milk to make cheese.
Made of specific bacteria that form acids in the milk, lowering the PH to a critical
acidity level.
Rennet- the main ingredient to coagulate milk into curds which eventually form
cheese. Can be animal based or microbial.
Curds-coagulated milk is formed into a smooth, custard-like solid called the
curd.
Whey- the basic by-product of cheese manufacturing. It is the portion of the milk
that did not precipitate out of the milk and form cheese curds.
Casein- the main protein found in milk and subsequently found in the cheese
curds. Defines cheeses that are used as an ingredient in industrial
applications.
Rennet based cheese- Cheese whose main coagulant is rennet. It is often
referred to as hard cheese, as it forms more solid curds than acid set cheese.
Acid Based Cheese- Cheese whose main coagulants are acids added to the
milk. It is often referred to as soft cheese, as it forms softer curds than rennet
set cheese.
Sources
I. Original Source: Mishnah Avodah Zarah 29b
‫ "מפני מה אסרו את גבינת‬,‫ שאל רבי ישמעאל את רבי יהושוע כשהיו מהלכין בדרך‬,‫אמר רבי יהודה‬
...‫ מפני שמעמידין אותה בקיבת נבילה‬,‫הגויים?" אמר לו‬
R. YEHUDAH SAID: R. YISHMAEL PUT THIS QUESTION TO R. YEHOSHUA AS
THEY WERE ON A JOURNEY, 'WHY,' ASKED HE, 'HAVE THEY(THE SAGES)
FORBIDDEN THE CHEESE OF NON JEWS?' HE REPLIED, BECAUSE THEY
CURDLE IT WITH THE RENNET OF A NEBELAH (AN ANIMAL THAT WASN’T
SLAUGHTERED PROPERLY)...(TAKEN FROM THE SONCINO TRANSLATION,
AVODAH ZARAH 29B)
II. Shulchan Aruch (YD 87:11):
“IF ONE COAGULATED MILK WITH THE SKIN OF A KOSHER CALF
ABOMASUM, IF THE RESULTANT MIXTURE HAS A TASTE OF MEAT- IT IS
FORBIDDEN, IF IT DOES NOT- IT IS PERMITTED.”
III. Shach (YD 87:11 SS 34):
“IF IT HAS A TASTE OF MEAT- MEANING, IF THE MILK DOES NOT CONTAIN
ENOUGH LIQUID TO NULLIFY THE PIECE OF ABOMASUM BY A RATIO OF
1/60.”
Sources
IV. Shulchan Aruch (YD 115:2):
“CHEESE PRODUCED BY NON-JEWS IS FORBIDDEN BECAUSE THE
COAGULATE IT WITH THE ABOMASUM OF AN IMPROPERLY SLAUGHTERED
CALF, EVEN IF IT IS PRODUCED USING VEGETABLE SOURCES.”
V. Rama (YD 115:2):
“IF A JEW SEES THE CHEESE BEING PRODUCED AND THE MILKING, IT (THE
CHEESE) IS PERMITTED. AND SO IS THE CUSTOM IN ALL OF THESE
COUNTRIES…”
VI. Shach (YD 115:2 ss 20):
“WITH REGARD TO CHEESE MADE BY A NON-JEW UNDER JEWISH
SUPERVISION, THE JEW NEEDS TO BE ACTIVE IN THE CHEESE MAKING
PROCESS, MEANING- TO INSERT THE PIECE OF ABOMASUM INTO THE MILK.
IF THE NON-JEW DOES IT, EVEN SUPERVISED AND WITH KOSHER
INGREDIENTS, THE CHEESE IS FORBIDDEN.”