Milk is inherently kosher. In order to be certified kosher, anything added to the milk, including vitamins, must be kosher.

There’s also a domino effect. As more companies become kosher, the suppliers of raw materials must become kosher as well. Consider the following scenario. A large pastry manufacturer, which uses hundreds of different ingredients, applies for kosher supervision. Ten suppliers lack adequate kosher supervision. The pastry company gives notice for them to either go kosher or they will no longer be able to use the company as a supplier. A domino effect has been set into motion. Each time another manufacturer becomes kosher, the demand for additional kosher supervision is created and the kosher food market expands.

Interestingly, we attribute much of the recent growth of OU certification to private label companies. Private label is a big business and manufacturers fiercely compete for the private label trade. When a private label company chooses a manufacturer, the availability of kosher certification plays a significant role in the decision-making process. Even if the kosher logo will provide only a slight marketing advantage, it may be enough of a factor to tip the scales in favor of the kosher manufacturer.

Then there’s the battle for shelf space. When retailers are deciding whether or not to carry a product, or what level shelf space for placement, they consider various criteria. In many regions, the kosher symbol may be the deciding factor.

How have the types of foods getting kosher certification evolved over time?

Rabbi Genack: Trends in kosher certification follow the broader trends in food production. As the market for complex and international foods has grown, we have grown along with it. The trend toward globalization also means that many foods and food ingredients once produced locally are now produced all over the world. As a result, we now have hundreds of inspectors, visiting factories in 100 countries to certify food products from exotic Asian items to American staples.

As the leaders in the field, our team is constantly on the lookout for changes in equipment and technology. We have inspectors who have expertise in every area of the food industry and follow the relevant trends, from enzyme production to dairy to flavors. This includes changes in technology, as well as changes in local culture.

Foods that combine meat and dairy may never be kosher.

For instance, in India, local custom has long accepted that there is very little non-kosher animal-based oils on the market. This must be continually monitored over time, as India’s local meat industry has begun to grow in the past few years.

As an example of technological change, a few years ago, a company developed a new proprietary technology to produce certain types of flavors. This ultimately had an effect on the requirements needed to keep their equipment in kosher status.

How does a company obtain kosher certification?

Rabbi Genack: The first step is to make certain that all the ingredients used in the product are kosher. The OU has a database of tens of thousands of ingredients that have been researched and approved as kosher over the years. When a new company applies to the OU for supervision to obtain certification, we check to see if the ingredients used in the plant are already recorded in our data base. If not, we will evaluate if these new ingredients are acceptable.

Evaluation of ingredients requires much technical skill. This is because ingredients are often made from sub-units, and in order to decide if an ingredient is kosher, one must investigate all the sub-units as well.

High-fructose corn syrup is a good example. It is made from corn syrup, which is made from cornstarch that comes from corn. Each phase of production requires the use of other ingredients. Sulfur dioxide is used to transform corn into cornstarch. The enzymes alpha amylase and glucose amylase help convert cornstarch into corn syrup, while xylose isomerase converts corn syrup into high-fructose corn syrup. To determine if high-fructose corn syrup is kosher, one must investigate all the different stages and study the ingredients used at each phase of production.