Many people believe that all rabbis who provide supervision can be presumed to be equally reliable. This great leap of faith is not rooted in reality nor is it a reasonable assumption to make. We would not entrust our physical well-being to any surgeon who is licensed to perform operations. Why should we entrust our spiritual health to every practitioner of kosher supervision? Perhaps the naive assumption that all hashgachos are acceptable is based on the simplistic view that kosher supervision requires minimal talent and training, and anyone who sets his mind to it can become a crackerjack mashgiach. Truth be told, supervision is quite complicated and a mashgiach or certifying agency must combine a variety of specialized skills.

There was a time, years ago, that rabbis came to the shores of America from the other side of the Atlantic. Unable to speak the language and lacking any marketable skills, many became mashgichim. Those days are over. Obviously, the fundamental requirement to enter the field of kashruth is Torah scholarship, but being a talmid chachom alone does not qualify one to be a rav hamachshir (supervising rabbi).

Modern food technology is highly sophisticated. The supervising rabbi must understand how spray dryers, deodorizers, reactors, retorts, steamjacketed kettles and other complicated pieces of machinery operate and function in order to understand the flow of the process in the plant This is particularly important if the plant produces dairy and pareve or kosher and non-kosher products, and it is necessary to insure that there is no crosscontamination of production.

In fact, in some plants (such as those that manufacture emulsifiers) there are no visible ingredients to inspect. Ingredients are processed by flowing through an intricate network of pipes that are miles long, and moving from one piece of machinery to another. If the supervising rabbi is not mechanically inclined, he will not have the foggiest notion of what is happening during production. I recall visiting a plant with a supervising rabbi who didn’t realize that kosher and non-kosher products were produced on the same equipment because he didn’t know how to trace the labyrinth of pipes that led from one reactor to another.

In addition, the supervising agency must be capable of reviewing and determining the status of ingredients used in the product. This often requires an in-depth knowledge of food chemistry in order to evaluate the sub-units that comprise the ingredients. To appreciate the broad range of ingredients used in food production it should be noted that the current OU data base of ingredients contains approximately 1.9 million entries! Many esoteric ingredients have technical chemical names such as chromium acetate natural (which may be nonkosher), and proficiency in Yoreh Daya alone (the section of the Shulchan Oruch that deals with matters of kashruth) does not enable a rabbi to determine if ingredients are kosher, dairy or pareve.

Today, there are many people in the field of kashruth who have developed a highly sophisticated understanding of food technology and modern food production. Nonetheless, it cannot be assumed that everyone who provides kosher supervision shares this high level of competency

A good mashgiach must also be a super detective, and many people in the field of hashgachah are not adept at investigative work. There are many stories that come to mind to illustrate this point, but my favorite anecdote is about a friend who was supervising a bakery. One day, his sharp eye noticed that the pies sold in the bakery were round, while the pie pans in the baking area were all square. The improbability of producing round pies in square molds led the rabbi to conclude that the bakery was purchasing ready-made frozen dough which they would then fill with fruit and bake off in the bakery ovens. Since the rabbi had not authorized the bakery to use any frozen dough, he confronted the management with this evidence of wrongdoing.

Unfazed by the accusation, the baker explained that just that day they had discarded all their old round pans after baking the last batch of pies. Undaunted, the rabbi came back to the bakery the next day and found shiny, new round pie pans on the shelf which perfectly matched the size and shape of the finished pies. However, suspecting that they were trying to pull the wool over his eyes, the rabbi inspected the underside of the pies. Encrusted in the shell was an impression of the name of the pie pan manufacturer which was imprinted on the molds used to make the pies. To the misfortune of the bakery, the name which appeared on the pie was not the same as the name engraved on the new pie pans. The rabbi immediately withdrew his supervision. No doubt, Sherlock Holmes would have been proud.

Indeed, by nature and training, many rabbis are unsuited for supervisory work. In their pastoral roles, rabbis are trusting individuals who see the best in people and give them the benefit of the doubt: As a mashgiach, one must don a different hat and become a suspecting and questioning sleuth. Many rabbis simply are not capable of assuming such contradictory roles.

There is one final reason why some supervisions are not up to snuff. There is a small group of rabbis whose halachic standards are inferior to those of most mainstream kashruth agencies. For example, some rabbis allow companies to use non-kosher ingredients in certain instances based on very questionable halachic decisions.

Some supervisions rely on very weak systems of control, and too much trust is placed in the hands of plant personnel. My colleagues and I have been to plants which required regular inspections but were visited only once every year or two. In other instances, companies were allowed to operate with compatible kosher and non-kosher ingredients, such as vegetable and animal glycerine, without a mashgiach checking that the nonkosher ingredients do not end up in the certified kosher product. I have also seen situations where non-Jewish plant managers oversaw kosherization between non-kosher and kosher, without a mashgiach being present.

In spite of the problems described above, there are many competent rabbis who provide thoroughly reliable supervisions. Nonetheless, it is difficult for the layman to evaluate different hashgachos, and people form opinions about supervisions on the basis of hearsay and superficial impressions. Many believe that any product that bears the name of the supervising rabbi in Hebrew characters can be presumed to be reliable. Apparently they are unaware that every rabbi is capable of spelling his name in lashon kodesh. It is not my intent to malign supervisions that appear in Hebrew. Many are very fine indeed. My point, however, is that evaluation of competency cannot be based on external appearances.

How does one make a truly informed decision about reliability? Check with your local rabbi. He generally has access to professionals within the field of kashruth who know the real score about the quality of supervision.

Over thirty years ago, shortly after I joined the OU staff, I attended a meeting of the Rabbinic Kashruth Commission of the OU. I made a presentation to the rabbinic committee about a new company that I was in the process of preparing for certification. One of the rabbis asked me a question and I responded, “I assume the mashgiach will take care of that problem.” The rabbi’s response was sharp and precise, and his words are worth passing on: ‘‘When it comes to kosher, we don’t assume!”

Rav Belsky ztz”l on Reconstituted Grape Juice