Why at times can the OU not tell me if something is made from kitnityot?

All products are made from ingredients, and ingredients are often made from sub-units. For example, a candy generally contains a flavor, and the flavor may be made from as many as 30 ingredients. Some of the ingredients in the flavor are made from other ingredients, as well.

The OU often accepts the certification of other reliable Kashruth agencies on ingredients. In such instances, we do not have access to the formula of the ingredients. As such, it would not be possible to evaluate the Passover status, since we do not know what ingredients are present in the product.

To use the example of the flavor, it is only possible to determine if a flavor is Kosher for Passover if one has the formula which lists the many components of the flavor. Thus, only the certifying agency of the flavor would be in a position to determine if the flavor is Kosher for Pesach.

At best, we can suggest the potential existance of Kitniyot or Chametz in a product that we do not certify for Passover.

If you are Sephardi, consume Kitniyot on Pesach, and therefore need a list of such products, we recommend that you discuss such questions with a Sephardi Rabbi.