A Glimpse into the System: Kosher Certification of Industrial Food

Since antediluvian times, when Tuval Kayin began fashioning metal implements (Breishis 4:22), developments in how items were manufactured progressed gradually with only incremental changes. About two-and-a-half centuries ago, with the advent of the Industrial Revolution, that trajectory was rapidly accelerated.1 Since then, continual technological advances have dramatically transformed manufacturing, to the point that modern methods barely resemble antiquated techniques. Food production is no exception.

Unless one was wealthy enough to enjoy spices transported over the Silk Road, pre-industrial food was locally sourced and made with familiar utensils. In stark contrast, much of what we eat today, whether the food itself or its sub-components (which are not necessarily disclosed on ingredient panels), is processed in distant factories on specialized equipment concealed from public view. Technicians wearing lab coats in laboratories serve as part of the contemporary food supply chain alongside the more traditional growers and pickers in the fields. Industrial methods are very different from scenarios discussed directly in the Talmud and classical sources, challenging our Poskim, more than ever before, to distill the fundamental halachic principles of kashrus from across multiple sugyos and adapt them to contemporary application.

A Fair Question

In an age where food traveling across oceans to reach our plates is the rule rather than the exception, a necessary outgrowth has been the development of organized kosher certification. Kashrus has developed into a multi-disciplinary specialization requiring knowledge of halachah and food science, company organization and facility structure, mechanical engineering and transport systems. Expansion of the global marketplace has required kashrus organizations to establish a presence on multiple continents.2

Unlike certified foodservice establishments which operate with a mashgiach onsite,3 it is not feasible for a full-time kashrus representative to be installed in every facility that makes certified products. What then is the halachic basis for certifying such food as kosher? How does a kosher symbol appear on food packages made in a factory located hundreds or even thousands of miles from the closest Jewish community?

The Brisker Rov and the Farmer’s Cheese

An anecdote about the Brisker Rov, zt”l, helps bring the question into focus4:

One year before Yom Kippur, the Brisker Rov’s family arranged with a farmer from a moshav to supply chickens for kaporos.5 The farmer, a simple Jew, was elated at the opportunity to provide a service for such a venerated rabbi. While loading up his truck with chickens, the farmer thought it would be most appropriate to present a gift. He brought along a container of his signature homemade cheese, which was considered a delightful treat by his friends and neighbors.

Upon entering the gadol’s home, jittery with excitement and a wide smile on his face, he asked if he may place his cheese down in the kitchen. He was taken aback when the Rov responded with a silent gaze, followed by a serious tone, “Reb Yid, does your cheese have a hechsher?”

The farmer was not accustomed to being in the presence of men of such great stature, certainly not a persona as imposing as the Brisker Rov, whose very being was suffused with awe of Heaven. He stammered with embarrassment, “No Rebbe, it doesn’t have a hechsher,” trailing off.

“There’s no hechsher?” the Rov clarified in a louder voice. At that moment, the farmer wished the ground would open up and swallow him. He became distraught, thinking how he could have done something so terrible by almost causing a tzaddik to eat food without a hechsher. Chalilah v’chas!

After he composed himself, the farmer replied, “Rebbi, I don’t have a hechser. However, the rabbi of my moshav occasionally enjoys my cheese. I can bring a letter from him attesting to its kashrus.”
Hearing this, the Brisker Rov’s features softened and he asked, “Please tell me, why don’t you have a hechsher on your cheese?”

Encouraged by the gentler mood, the farmer answered, “I don’t produce this cheese commercially; it’s for my personal use, and to share with family and friends. I know myself that it’s kosher, and everyone on the moshav trusts me so I never needed a hechsher.”

The Rov wanted to be absolutely certain and pressed once again, “Are you sure that you don’t have a hechsher?” The farmer answered affirmatively and volunteered, once again, to come back with a letter from his rabbi.

With this the Rov was satisfied and smiled, “Wonderful! Thank you kindly. Please place the cheese in the kitchen. It’s good that it doesn’t have a hechsher, because foods with a hechsher I don’t eat!”

Eid Echod Ne’eman

What was the Brisker Rov’s objection to a hechsher? The story as written doesn’t elaborate. We can conjecture that his line of questioning was to determine if the halachah of ‘eid echod ne’eman b’issurim’ (םירוסיאב ןמאנ דחא דע, lit. ‘one witness is trustworthy with regard to matters of prohibitions’) was applicable in this case. This principle allows one to trust someone else regarding the kosher status of food items,6 provided that they (he or she) are: 1) Obligated in kosher, 2) Possess rudimentary knowledge of kosher laws, 3) Is known to adhere to them, and 4) Is shomer Shabbos.7 Eventually, the Brisker Rov was satisfied that this farmer was, indeed, a valid eid echod worthy of vouching for the kashrus of his cheese. But what is the halachic mechanism of a hechsher?

Whether or not the Brisker Rov would feel comfortable relying upon today’s highly developed kashrus system is an academic question. For over a century, Poskim have endorsed kosher certification on industrially-produced food items. This is an unavoidable reality as one would be hard-pressed to find someone nowadays who subsists without some level of industrially-produced food.

For the most kashrus-sensitive categories of industrially-produced food, our question is not pertinent since mashgichim serving as ‘eidim’ are present from the beginning of production through final packaging and sealing.8 These categories, per STAR-K policy, include:

  • Meat– Experts in shechitah, bedikah, nikkur, and melichah, are substantially involved at every step of production.9
  • Wine and grape juice – Production takes place exclusively by mashgichim.
    Fish – STAR-K requires a mashgiach to check each fish for simanei kashrus (specifically, scales on the skin or a clearly visible outline of scales) before processing. This policy includes tuna and salmon (red pigment is not accepted as a siman muvhak).
  • Cheese – A mashgiach must be present to add the rennet / coagulant that begins the curdling process.10 Onsite verification of product identity is required before packaging.
  • Milk – For Cholov Yisroel productions, a mashgiach is present throughout every step. This includes: kashering the tanks and pasteurizer, cleaning collection vats, checking the herd for questions of triefah, and supervising the process from milking through bottling.11
  • Kosher for Pesach – A mashgiach is often present for Passover-certified productions, even when its year-round kosher counterpart does not warrant that degree of supervision.
  • Bishul Yisroel – Products certified according to the STAR-S standard for Sefardim and Eidot HaMizrach require mashgiach involvement during production. STAR-K standard follows the Ramoh, allowing for a lesser degree of involvement, as long as a mashgiach adds to the fire.
  • Insect Checking – For insect-prone produce, e.g., lettuce, broccoli or strawberries, an onsite mashgiach checks a sample from each batch to ascertain that the wash process is effective to remove bugs per kashrus standards.12 If not, the kosher symbol may not be applied.

These categories demand a disproportionate amount of resources on the part of kashrus organizations. However, they comprise a small minority of the million-plus kosher-certified products in the market. Most products have lower levels of kosher sensitivity and, as such, Poskim accept a reduced level of oversight. What are some of the considerations that allow kosher certification to be granted on industrially-manufactured products?


Yotzei V’Nichnas (סנכנו אצוי / intermittent inspection) is a halachic principle recorded in Shulchan Aruch (Yoreh Deah 118:10, 129:1), which states that kosher integrity can be preserved even without a mashgiach’s constant presence. Intermittent appearances are enough, provided: 1) The mashgiach’s schedule is unpredictable; he does not divulge how long he will be away; 2) He can arrive unannounced without prior notice; 3) There is no lock barring his entrance; he can enter at will. Together, these criteria form a ‘mirsas’, an apprehension, on the part of a kosher producer lest he be caught introducing unapproved ingredients.13 Shach (#32) comments that this type of supervision is permitted even ideally, l’chatchilah.

A strict interpretation of the second and third conditions is usually not fulfilled in modern industrial plants. Many facilities require visitors to register at the front desk due to food safety regulations and bio-terrorism protections (and for corporate espionage prevention), diminishing the effectiveness of yotzei v’nichnas. Often, a mashgiach must be accompanied by plant personnel throughout his visit.
The first condition is also affected by one viewpoint presented in Shach (ibid.) which asserts if the duration between visits is too long, the hashgochah can only be accepted bdi’eved, after the fact, surely not a foundation for a sound kosher program. What exactly is considered ‘too long’ depends on specific conditions in the plant (see Chelkas Binyamin 118:98). The second viewpoint in Shach does not differentiate between short and long intervals. In practice, visit frequencies at plants are determined on an individual basis;14 whether or not they technically meet the duration mandated by the first viewpoint is debatable.

Nonetheless, the validity of using yotzei v’nichnas as part of a superior Mehadrin certification protocol is bolstered by other factors:

  • Beis Yosef (Y.D. 118, in Bedek HaBayis) writes that when non-kosher ingredients are not commonly found in the vicinity, we aren’t as concerned that something non-kosher will be intentionally introduced into the product. Many plants are conferred with an “all-kosher” status, which is verified by the mashgiach during his visits.
  • Shulchan Aruch (based on Tosfos to Avodah Zarah 12a) rules that when no benefit is gained by substituting kosher ingredients with non-kosher ones, we may rely on yotzei v’nichnas even when some of the conditions aren’t met.15 An extension of this notion can sometimes apply even when a kosher version of an ingredient costs more than a compatible, non-kosher version. If the short-term savings is significantly outweighed by potential fallout from loss of certification and consumer trust, were they caught using unapproved ingredients, the mirsas factor might remain intact.

Poskim recognize other grounds for mirsas as a legitimate premise to confirm kashrus. For instance, Ramoh (Teshuvos #54), in 16th century Krakow, was asked to decide the kosher status of imported olive oil. At that time, it was common to transport olive oil in wooden barrels, and there was suspicion that the barrels were coated with lard to prevent absorption and seepage. Among the explanations given to permit the oil, Ramoh cites Rashbah (Teshuvos I:67) who ruled on a similar question presented to him in 13th century Barcelona. There was concern in Talmudic times that unsupervised workers might coat kosher cheese with lard (Avodah Zarah 35). However, Rashbah held that’s no longer a problem when living among Catholics who don’t consume meat on Fridays (especially during Lent). Fear of being penalized by the authorities for selling cheese with meat residue creates a mirsas that is adequate for kashrus. For the same reason, Ramoh concluded that we need not worry that olive oil barrels are coated with lard.

In his landmark teshuvah, Igros Moshe (Y.D. I:47, dated 5714/1954) similarly accepts that the prospect of government-imposed fines for tainting cow milk with milk sourced from other animals is sufficient to create a mirsas that permits using regular non-Cholov Yisroel milk (‘cholov companies’) in the United States. Even those who disagreed with Rav Moshe Feinstein, zt”l, did not dispute the legitimacy of such a mirsas. Their argument was either that halachah places special restrictions on milk that cannot be satisfied by government controls, or that legal sanctions in most jurisdictions are not strong enough to deter fraud. (It should be noted that Rav Moshe, zt”l, himself wrote that it’s preferable not to rely on this leniency, ibid. and Y.D. IV:8. Thus, the STAR-K symbol on dairy products is reserved exclusively for Cholov Yisroel. Products using standard milk are eligible for STAR-D certification.)

Mirsas, by definition, is a deterrent formed by the possibility of detecting irregularities. Therefore, it’s important that hashgochah systems incorporate tools that encourage transparency and increase the chance of noticing unanticipated discrepancies. In addition to regular spot checks in ingredient storage (and disposal) areas and production rooms and warehouses, records should also be reviewed. Many STAR-K inspectors are trained in audit procedures, such as trace-back and mass-balance exercises.

Reputation Protection

Another aspect of human nature which is recognized by halachah as a way to confirm honesty is the innate drive most people have to preserve their good reputation. As Benjamin Franklin pithily observed, “It takes many good deeds to build a good reputation, and only one bad one to lose it.” One may expect scrupulousness, especially when one’s livelihood is at stake, unless cause is given to suspect otherwise.

This assumption is applied by Shulchan Aruch in Y.D. 114:5 where he rules that pomegranate juice used for medicinal properties may be purchased from a retailer who lacks the qualifications of an eid echod. The Rishonim were not concerned the product was adulterated with cheaper non-kosher wine-vinegar because doing so would dilute its efficacy, and the seller does not want to tarnish his reputation.16 Ramoh extends this permission to purchasing other similar items where product authenticity is expected.

The halachic term for professional integrity is ‘uman lo mairah umnuso’ (ותנמוא ערמ אל ןמוא / a professional does not undermine his reputation). Commentators to Shulchan Aruch impose a few limits on its application. Shach (Y.D. 98:2, 302:4) writes that we may rely on a professional’s word only when the truth is readily verifiable by other means. Magen Avrohom (O.C. 20:1) states this assumption works only when all customers, not just adherents of kosher, would be offended by product adulteration, like tainting olive oil with other oils.17 But if it affects just the kosher segment, for instance when switching grape juice concentrate in a sweetened beverage from a kosher source to a cheaper non-kosher one, we can’t apply uman lo mairah since the substitution is inconsequential to the general public.18

In 5712/1952, Rav Yechezkel Grubner, zt”l, from Detroit19 suggested it should be possible to ascertain that oil used in a product was of kosher vegetable origin and not from animals by obtaining a written statement from the manufacturer disclosing ingredient contents.20 His justification was based partly on uman lo mairah, along with the ability to substantiate the claim by chemical testing and also the threat of legal reprisal. The veracity of the statement was further strengthened by the fact the question was posed to the company asking them to address allergen concerns, not exclusively kashrus.

Rav Moshe, zt”l, (Igros Moshe Y.D. I:55), in his reply to Rav Grubner (5715/1955), concurred that written statements officially issued by a company are a credible way to verify kosher status. Three decades later (Igros Moshe Y.D. IV:1, dated 5744/1984), Rav Moshe clarified that granting kosher certification to a factory on this basis alone is improper. It can only help in conjunction with regular visits by a mashgiach who is familiar with the layout and will notice any changes. Rav Yosef Eliyahu Henkin, zt”l, (Gevuros Eliyahu Y.D. #34) also corresponded with Rav Grubner. He distinguished between items that are inherently kosher, where uman lo mairah (under the right conditions) can be effective to resolve doubt that non-kosher components were added, and items that can either be kosher or non-kosher where uman lo mairah cannot be a factor in determining kashrus. Furthermore, even in the former case, it’s only a device to rely upon occasionally when absolutely necessary.

Practical Program

The crux of any reliable kashrus certification program is always the physical plant visits by mashgichim and administrative reviewers whose trained eyes can detect more than the narrow snapshot seen during the time spent in the plant.21 But the complexity of modern food production demands employing other measures to assure the success of a kosher program. Based upon the principles established above, additional safeguards are implemented when providing certification at industrial plants. Among them are:

  • Legally enforceable contract agreements signed by all relevant parties affirming compliance with the kosher program specific to the company.
  • Partnering with companies whose professional management will develop a good working rapport with the kashrus administration team.
  • Formal registration of all ingredients and processing aids used in kosher-certified products, and disclosure of all activities in the plant, verified onsite by the mashgiach. (With the understanding that maintaining strict confidentiality is integral to our work.)
  • Approving labels affixed with the kosher symbol before printing; onsite label verification by the mashgiach.
  • Occasionally sending product samples to a laboratory for component identification.
  • Utilizing government legislation which compels companies to increase transparency, especially the Food Allergen Labeling Act of 2004 and the Food Safety Modernization Act (FSMA) of 2011.
  • Establishing failsafe systems in areas where mashgiach travel is limited, or standards of integrity differ from our expectations, only to certify products that will be fully kosher in any event. (Understandably, this begs the question: Why do such products need kosher certification at all? The short answer is because without plant inspections we don’t know that to be the case.22)
  • When a plant uses kosher/non-kosher compatible ingredients in the absence of a strong verification system, or when processing takes place on shared equipment, we may only certify special kosher productions in the presence of a mashgiach.

In this age of technology and specialization, we have witnessed the shift of responsibility for kosher certification from the local rabbinate to professional organizations. In a sense, STAR-K Certification is a bridge between the old, traditional model and the new system. HaRav Moshe Heinemann, shlit”a, a leading moreh hora’ah (halachic authority) for the Baltimore kehilah to whom numerous Jewish communities world over turn for piskei halachah and guidance, stands at the helm of STAR-K and remains actively involved with all kashrus-related matters. Under his direct leadership and direction for over four decades, a robust organizational structure has developed that is equipped to stay abreast of developments in the food industry across the globe. With siyata d’shmayah, our efforts will continue to play a role in protecting kedushas Yisroel.

  1. A predictive allusion to this unprecedented era is found in Zohar (Parshas VaYeirah, 117a), “In the sixth century of the sixth millennium [corresponding to secular year 1840], the gates of supernal wisdom will be opened above, along with springs of the lower wisdom below [interpreted as science and technology], preparing the world for elevation in the seventh millennium.”
  2. Besides the United States, STAR-K maintains offices in Australia, Brazil, China, Costa Rica, India, Philippines, Sri Lanka, and Eretz Yisroel.
  3. STAR-K requires constant on-site presence of independent (non-owner) mashgichim for: meat restaurants, caterers, and supermarket departments. Dairy retail stores that involve cooking (e.g. pizza shops) must always have an approved shomer Shabbos on premises. Additionally, each location is reviewed frequently by roving STAR-K administrators who maintain regular communication with the mashgichim. Venues shared by non-kosher events require much more vigilance and employ multiple mashgichim. An extreme case is the AIPAC conference held in Washington, D.C. (pre-coronavirus) with upward of 18,700 attendees, necessitating a regiment of 55 mashgichim over 3 days. (See https://www.star-k.org/articles/news/3665/what-it-takes-to-serve-kosher-to-18700-aipac-conference-attendees/)
  4. עובדות והנהגות לבית בריסק, חלק א’, עמוד ר
  5. Quite likely, the Brisker Rov himself did not participate in this practice. See http://www.torahmusings.com/2012/11/rav-soloveitchik-and-kaparos/ Yet, he did not object when family members engaged in it.
  6. בענין מי שאכל דבר ע”פ עד אחד נאמן ואח”כ נמצא שהעד טעה ובאמת המאכל היה אסור, אם נחשב כשוגג או אונס לענין כפרה, וכן לענין טמטום הלב, ע’ מאמר בנושא זה מאת הר”ר מרדכי פרנקל שליט”א הנדפס בקונטרס דרך כוכב (לייקוואוד תשע”ה), עמוד לז’. ע”ע ספר מסורת משה, חלק א’ יורה דעה אות א’.
  7. Even when a proprietor meets the qualifications of an eid echod, accepted practice is that food produced for commercial sale needs an independent hechsher. See Kashrus Kurrents, Summer 5777-2017, In Whom Do We Trust: Examining Conflicts of Interest in Food Certification, by this author.
  8. See Kashrus Kurrents, Winter 5780-2020, Signed, Sealed and Delivered: The Requirements for Chosomos on our Foods, by Rabbi Nissan Dov Miller.
  9. Furthermore, STAR-K facilities accept meat only from sources that are approved by STAR-K’s Rabbinic Administrator, even when the meat carries a reputable hechsher. See Kashrus Kurrents, Winter 5776-2016, Special Meat Edition.
  10. See Kashrus Kurrents, Spring 5771-2011, Eating Her Curds…No Way, by Rabbi Tzvi Rosen.
  11. See Cholov Yisroel: Does a Neshama Good, by Rav Moshe Heinemann, shlit”a.
  12. See Kashrus Kurrents, Spring 5778-2018, Staying Up to Date on Insect Checking / Bedikas Tolayim, by Rabbi Sholom Tendler.
  13. In Shulchan Aruch, yotzei v’nichnas is applied in various places, including: kosher food production, tzitzis making (which must be done lishmah), and clothing manufacture (shaatnez).
  14. Members of AKO (Association of Kashrus Organizations) are committed to minimum visitation frequencies that are based upon kosher-sensitivity assessments of various food production types.
  15. Albeit, some Poskim apply this leniency only when the food belongs to and is produced in a facility owned by someone with ne’emanus as defined above for an ‘eid echod’. See Gevuros Eliyahu (Rav Henkin, zt”l) Y.D. #12.
  16. Today, one should preferably seek bottled pomegranate juice with a hechsher because it may have been pasteurized on equipment shared with non-kosher products, or it may contain additives (or can be tevel).
  17. See further: Chacham Tzvi (#39), brought in Pri Megadim M.Z. 253:18
  18. See Nodah Bi’Yehuda (O.C. II:72) who argues on Magen Avrohom. In a teshuvah addressing the permissibility of granulated sugar on Pesach when there is suspicion it may have been transported in containers previously used for flour or perhaps the sugar itself was adulterated with (cheaper) flour, he appears to hold that businessmen will resist the temptation to cheat even when it affects only kosher consumers, since such behavior will undermine their reputation among all customers.
  19. Kneses Yechezkel Y.D. I:49-51, corresponding with Rav Yosef Teumim, zt”l, also from Detroit.
  20. This discussion took place in the 1950s. Today, it’s understood that vegetable-based oils may have been processed on shared equipment with animal fats and are thus rendered non-kosher. See Kashrus Kurrents, Summer 5780-2020, A Kosher View of Refined Edible Oils by Rabbi Tzvi Rosen.
  21. For many reasons, ‘virtual’ inspections via teleconferencing are not a replacement for this critical component.
  22. This topic deserves its own discussion in another Kashrus Kurrents article, iy”H. Stay tuned!