One of the most fundamental concepts in kosher supervision, aside of course from the requirement that all ingredients in a product must be kosher, is the idea that the equipment that is used to process the foods must be exclusively designated for kosher use as well. The same rules hold true for separation of dairy and pareve equipment. Furthermore, even if equipment is designated for kosher use only, if a plant has compatible equipment that is also used for non- kosher or dairy, this will raise concerns about accountability. What if one line was to malfunction? What safeguards are in place to prevent the kosher product from being produced on the non- kosher or dairy line, or to prevent the non-kosher product from being produced on the kosher equipment? Only if the equipment is truly incompatible would this concern be alleviated.
Food that is cooked in a non-kosher kettle is not kosher. For example, if soup is cooked in a kettle that previously cooked non-kosher sauce, then even if the soup is made with all kosher ingredients, the soup is now non-kosher. Furthermore, if this soup is then transferred, while it is still hot, to another kettle, the second kettle becomes non-kosher as well. Once a kettle becomes non-kosher, it can only be brought back into kosher service after it undergoes a kosherization.
This usually entails a thorough cleaning, followed by a 24-hour downtime, and then a boil out (i.e., filling the kettle with plain water and bring it to a rolling boiling so that the water boils over the sides of the kettle). Depending on the size of the equipment and its heating capacity, it can take some ingenuity or some engineering upgrades at times to ensure that boiling water reaches all parts of a given piece of equipment. For example, spray dryers are kosherized by spraying all parts of the equipment with boiling water for 20-30 minutes. To ensure that all areas are blanketed with boiling water may require installing additional spray balls.
If a non-kosher product is only put into a tank cold, and does not remain there for more than 24 hours, the tank would only need a good clean out; it would not require 24-hour downtime or a boil out. So for example, if a product is blended cold in tank A and then sent through an HTST regenerating heat exchanger and deposited cold into tank B, both tanks A and B can be thoroughly cleaned out and returned to kosher service. However, the HTST in which the product is heated would require 24-hour dormancy and then a several-minute flush of plain boiling water. For these purposes, temperatures below 110° F are considered cool, while temperatures above 120° F are considered hot. If the temperature is in the middle, (between 110° F – 120° F), depending on other relevant factors, the rabbinic coordinator (RC) or the rabbinic field representative (RFR) would have to make the decision on how to proceed. Whenever a plant processes both kosher and non- kosher, and especially when kosherizations are required, transparency and communication between the plant and the rabbis is of the utmost importance.
RABBI ELI GERSTEN SERVES AS OU RABBINIC COORDINATOR AND RECORDER OF OU POLICY. HE IS A FREQUENT CONTRIBUTOR TO BTUS.