There was a time when the expression “pass the butter” was as benign as it sounds, a time when the kosher consumer believed that butter presented no kashrus concerns. After all, butter cannot be made from the milk of a non-kosher animal, which will not congeal. For this reason, many kashrus agencies long considered butter a Group One ingredient — the category applying to products that are kosher without supervision.

Some time ago we learned that significant kashrus issues do arise with butter. Developments in the food industry are ongoing, and such changes often have important kashrus ramifications. Butter is mostly butterfat, with some additional milk elements and water also present. Butter traditionally is made from sweet cream (commonly called heavy cream), which is the thick layer skimmed off the top of milk. Sweet cream contains both butterfat and buttermilk. The churning action causes butterfat lumps to bond together into balls of butter, while at the same time the buttermilk separates. You can easily make butter at home, by taking heavy cream and mixing it with a beater until it hardens to butter consistency.

If butter contained only this cream and perhaps some salt and water, as used to be the case, we could continue to classify butter in Group One; however, this is no longer true.

The primary kashrus issue concerning butter is that whey cream is often added to it. Whey cream is a byproduct of cheese manufacturing. When milk is curdled to make cheese, it separates into two parts: the mass that will become the cheese, and a watery compound called whey, part of which is cream.

Today’s economic climate finds companies seeking to profit from every possible aspect of their production; nothing is discarded if it can be used in some way or sold. Having discovered that whey cream can be made into butter, cheese companies sell the whey cream to butter companies.

Why would a butter company add whey cream to its products? The answer again is economics; whey cream is less expensive than sweet cream. If a company can successfully make butter by using whey cream, the company stands to save money.

And here our problem begins.

Cheese needs kosher supervision for two reasons. First, all ingredients in cheese, including the rennet (the curdling mechanism) in which it is set, must come from a kosher source (either microbial, genetically engineered, or a properly slaughtered animal). The starter culture also must be kosher, as must any additives that enhance the flavor.

If cheese is made from non-kosher ingredients, we treat the whey as not kosher as well. (It should be noted that Rabbi Moshe Feinstein, zt’l, considers this whey kosher. However, because of complexities in using whey cream that is made in this fashion, the major kashrus agencies do not permit it in the products they certify.)

The second kashrus issue concerns gevinas akum, the special law that requires participation by a Jew in kosher cheese production. Even if all the ingredients in cheese are kosher, halachah requires Jewish involvement in the process. (For a detailed discussion of kosher cheese production, see “The Art of Making Cheese,” The Jewish Homemaker, June 1998.) Now, when the cheese has not been cooked, we permit the whey if all its ingredients are kosher. This is because the whey is not cheese and is not subject to the stricture of gevinas akum. As long as the cheese is not cooked, no gevinas akum has been absorbed into the whey.

However, certain cheeses are cooked; Swiss cheese is the most common example. When producing Swiss cheese, the cheese is heated in its own whey. If the heat reaches 120°F, the whey is considered cooked in gevinas akum. In this scenario, the taste of gevinas akum has been absorbed into the whey. The prevailing view among kashrus agencies is to be strict with this whey as well. Therefore, if a Jew did not participate in the cheese production, we will not certify the whey or whey cream byproduct.

(Note: Jewish law makes clear that the absorption of taste by one food of another food occurs at cooking temperature, a stage referred to in halachah as “yad soledes bo.” We consider the cheese “cooked” if it is heated to 120°F. Again, below this temperature the whey contains no absorbed taste of cheese; as long as the ingredients are kosher, the whey is kosher. Most Swiss cheese is produced above 120°F. There are, however, Swiss cheeses that are made at a slightly lower temperature; the whey recovered from the production of these cheeses does not present a gevinas akum problem.)

An additional, very serious concern arises with some Italian cheeses, such as mozzarella. One can argue that there is room for leniency with Swiss cheeses, because the whey separates from the cheese before the cheese-making process is completed. At this earlier stage, one can make the case that the rule of gevinas akum is not invoked.

However, many Italian cheeses are processed differently. After these cheeses are finished, they are cooked in water at 165°F, in order to make them malleable. (That is how you get the “stretching” quality of cheese used for pizza.) During the cooking process, whey is absorbed into the cook water. The whey that is drained off with the cook water presents a clear gevinas akum problem, for two reasons. First, the cheese-making process has been completed before this cooking takes place. Second, while one may make the case that 120°F is not quite yad soledes bo, there is no question that 165°F is yad soledes bo. There is no doubt that non-kosher cheese is absorbed into this whey.

All mozzarella cheese-makers sell the whey cream that is extracted from this cooking water. The presence of this whey cream in butter renders the butter not kosher.

There are several grades of butter; AA, the highest grade, would tend to have the least whey cream added, since whey cream compromises the taste of the butter slightly. Lower grades are more likely to contain whey cream.

Is it possible that the butter you buy off the shelf contains non-kosher whey cream?

The answer to this question gives us insight into how some United States Department of Agriculture regulations are actually enforced. Its official guidelines seem to limit the use of whey cream to lower-grade butter. This is because whey cream can make butter taste slightly less bland than AA quality demands. (When it comes to butter, the blander the better.) And yet, we are in possession of a letter by a USDA official stating that the agency tests butter for compliance by tasting it, not by checking the source of the ingredients. In other words, if a company can produce a butter that contains whey cream and yet tastes good enough, this butter will be approved as AA grade by the USDA.

We have found companies that use up to five percent whey cream in their AA butter. The whey cream is not batel b’shishim (halachically nullified in sixty parts of kosher product), and so, if the whey cream is not kosher, neither is the butter. And as we said, companies certainly use a higher percentage of whey cream in lower-grade butter.

Another interesting fact is found in literature concerning skim milk powder in Europe. Government-subsidized skim milk powder in Europe cannot, according to the law, contain whey. Since whey powder is cheaper than skim milk powder, companies have the temptation to adulterate skim milk powder with whey. Therefore, a test was developed to ascertain if the skim milk powder is indeed adulterated. We see from this how even governments insist on strongly monitoring the situation.

Non-kosher whey cream can lead to a kashrus problem even if it is not present in the actual butter you find on your store shelf. For example, non-kosher mozzarella cooker whey cream renders the equipment in which it has been produced not kosher. If butter from kosher ingredients subsequently is produced on the same equipment, the butter is not kosher. The only way to make kosher butter would be by kashering the equipment. (This is especially problematic in butter oil production, which we will discuss later.)

Additionally, many butter companies do not limit themselves to the product they manufacture; they also buy butter on the open or futures markets. They then take this bulk butter and chip it down to retail size. When it comes to kashrus, there is absolutely no control over such butter and its ingredients.

There is a further problem with butter, pertaining to the trucks in which whey cream is transported. Kosher and non-kosher cream may legitimately be transported in the same truck as long as they are properly separated in different compartments. However, there are trucks where these creams are separated, yet are pumped in and out of the trucks with one pump. In such a case, the kosher product must be pumped first, so that it does not become contaminated. But it is not always possible to ascertain that this procedure is being followed.

Currently the OK does not certify any butter plants in which non-kosher whey cream is used in any fashion. Therefore, this co-mingling of cream is not an issue with OK-certified products, but it remains an issue for the consumer.

Another issue concerns the chalav Yisrael status of butter. There are many people who drink only chalav Yisrael milk and eat only chalav Yisrael products, yet will consume butter that is not chalav Yisrael. The reason for this is that cream from a non-kosher animal will not congeal into butter. However, now that we have established that there may indeed be a portion of the butter that comes from not-chalav Yisrael whey cream, extra caution must be exercised by those who are particular about chalav Yisrael.

There is a kashrus agency that claims to certify only chalav Yisrael milk products, but certifies non-chalav Yisrael butter. Remember, the butter may have whey cream; even if the whey is kosher, it is not chalav Yisrael! Kosher consumers are entitled to inquire among the kashrus agencies concerning the status of certified butter under their supervision.

A similar matter is that of butter oil, or anhydrous milk fat, which is produced by draining off the water in butter. Butter oil is used at the industrial level.

The presence of whey cream in butter can be established by a test for glycomacropeptides, a substance that is present only in whey cream butter. Even a small quantity will be sensed. However, this test is ineffective once the butter has been made into butter oil. It is therefore quite possible for undetectable whey cream to be present in butter oil.

Moreover, during a recent visit to one of the biggest producers of butter oil in Europe, I learned that Europeans have a type of butter called intervention butter. This is a government-subsidized butter that legally may be used only as an industrial ingredient. By law, intervention butter cannot contain whey cream butter, but a different problem exists.

How does the government determine that the intervention butter is not diverted to consumer use? It adds a tracer agent to the butter. There are two types of intervention butter, and two types of tracers that may be added. The two tracers are analytic tracers, which can be detected only in a lab, and organoleptic tracers, which can be detected by tasting the butter.

The two versions of intervention butter are Formula A and Formula B. Formula A butter is used in baked goods, chocolate couveture, confectioneries, chocolate fillings, uncooked dough, powder pre-mixes, prepared or preserved meat (not pertinent to the kosher market) or fish, soups, and sauces. Formula B is used in ice cream, ice desserts, and ice cream powder pre-mixes.

The analytic tracers used in Formula A are glycerol triheptanoate and stigmasterol (the latter from a vegetable source). The organoleptic tracers used are apo carotene, vanillin, and sugar, all three of which may be acquired with a hechsher. The analytic tracer used in Formula B is sitosterol (obtainable with kosher supervision). The organoleptic tracers are again apo carotene, vanillin, and sugar. The main problem with the above is glycerol triheptanoate, which must have kosher supervision, but at present is not available with certification.

In Europe there are numerous companies manufacturing butter oil where the issue of non-kosher equipment due to whey cream is very much a concern.

Yet another problem we found in Europe is the use of animal fats in butter oil blends. First, this butter oil itself becomes not kosher. Second, the butter oil blends are used by the food industry in various products. This also leads to an equipment problem, since the same equipment used for these non-kosher blends is used for regular butter oil.

With the above information in mind, it is quite evident that it is not simple for a kashrus agency to certify butter. Some time ago the OK concluded that butter can no longer be classified as a Group One product. Our strong advice to consumers is not to buy butter unless it carries a reliable hechsher.

As technology changes, the OK will continue to exercise vigilance in promoting the interests of kosher consumers.