Kosher Certification of Yogurt – Hurdles and Victories


We’re traveling somewhere that does not have much kosher food available.”

“Not to worry; I’ll just buy yogurt there, and all will be fine.” 

“You wish!”

Yogurt seems so simple, but its kosher challenges can be numerous and unexpected. Let’s take a closer look.

At first glance, what is yogurt? Well, it’s milk. Umm, sort of. It’s fermented milk. We’re getting closer, but we’re not yet there. It’s fermented milk that often contains kosher-sensitive stabilizers and fruit-base. Okay, now we really have something to discuss.

Yogurt poses three main areas for serious kosher consideration: 1) cultures (used to ferment milk into yogurt), 2) stabilizers (used to give body and texture to most yogurt), and 3) fruit-bases (used to – no explanation needed for this one!)

Of course, to produce yogurt one must start with milk. But this is not so simple. To achieve the right balance of fat and solids and the desired texture, non-fat dry milk and whey protein may be added to the milk, creating a milk blend, whose ingredients now become a kosher concern. Stabilizers may be added to the milk blend as well. Stabilizers can come from gums, starches, and pectin – which are inherently kosher – and they can also come from gelatin, which is of animal origin and typically poses a grave concern for kosher certification.

Kosher-certified yogurt plants must be very careful regarding gelatin stabilizers. In some cases, kosher-certified yogurt plants use gelatin stabilizers for non-OU product, after detailed coordination with OU Kosher – in order to arrange for the segregation of gelatin stabilizers and specific clean-out and/or kosherization of affected equipment, as the case may be. Although it is more costly, some yogurt companies opt for special OU-certified gelatin, which comes from fully kosher-processed animals. This has been a terrific solution for some companies.

Greek yogurt has been a boon both for the dairy industry as well as for kosher certification. The reason for the latter is that instead of being thickened with stabilizers, Greek yogurt achieves its thick consistency by being strained to remove moisture; stabilizers are therefore not typically used, and there is thus one fewer kosher concern.

The milk blend is then pasteurized, homogenized and cooled, after which it is inoculated with lactobacillus bulgaricus and streptococcus thermophiles cultures. These cultures cause the milk’s lactose (sugar) to ferment into lactic acid, which acts on the milk to lower its pH, thereby causing the milk to clot into a yogurt gel and attain a distinct flavor.

Some yogurt also contains probiotic cultures, which can boost the body’s immune system and contribute to gastrointestinal health as well as to the body’s ability to digest lactose. But these cultures are not necessary in order to create yogurt.

Although the cultures used for yogurt production are inherently kosher, they can often be manufactured in non-kosher environments, and their source plants thus require tight kosher controls and solid kosher certification.

After inoculation with cultures, the product is held for several hours at 108 F degrees until the pH reaches 4.5, during which time fermentation, gelling and development of flavor occur.

The product, which can now justly be called yogurt, is then cooled to 46-47 F degrees, halting the fermentation process.

Afterwards, fruit-base is commonly added. One might assume, “Sounds kosher-easy. Does fruit-base need kosher certification?” –  yet one would be wrong. Fruit-base often contains carmine, a non-kosher deep red color derived from insects. Hence, fruit-base manufacturers require reliable kosher certification.

The yogurt is then pumped into packaging, and eventually makes its way to your table.

The three hurdles of yogurt certification can definitely be overcome, as numerous large, midsize and small yogurt companies successfully retain OU Kosher certification.  The OU is proud to be of service to these great companies, and we hope that they will be of service to you.

Rabbi Avrohom Gordimer is a rabbinic coordinator at OU Kosher, where he serves as account executive for the kosher programs of 115 OU-certified client companies. Rabbi Gordimer specializes in the dairy industry, and is a frequent contributor to OU publications as well as to Israel National News and various other online and print media.