Many years ago, it was a common, though unsound practice of many frum people to check the kosher status of food items they wanted to eat by reading the ingredient listing printed on the label. This was not a good idea for two primary reasons: Although ingredients are generally required to be identified, there are circumstances when an ingredient may be exempt from being identified. In addition, there is no way for a consumer to determine what else was made on the equipment by looking at the label.
Baruch Hashem, the kosher consumer has become savvier and this method of determining the acceptability of a product has fallen into disuse.
However, there is one more area of household food items for which people occasionally rely on the old method – Vegetable Oil. The belief that vegetable oil can only be vegetable oil coupled with the notion that animal fat can’t be produced on the same equipment has sown some confusion in this area. It is definitely true that the consumption and use of animal based fats have dropped dramatically over the past decade. This is primarily due to health reasons among the general public. However, this does not mean that the non- kosher oils and fats are not produced on the same equipment as vegetable oil.
The only time that there is no common equipment issue is in the crush plants. This is where the vegetable or bean of choice is brought to be extracted. It is generally done by physically crushing the object to squeeze out the oil. Occasionally, a chemical solvent, such as hexane, is used to help along the extraction. Animal fat is not extracted in the same way, so at the crush plant there would be no concern of commonality. This is not a source of comfort for the housewife, because she does not use crude vegetable oil to cook. Chances are if she would, there would be a lot of leftovers!
After the oil has been manufactured into the crude state, it is either refined in the same plant or transported to a different plant for refining. Both of these possibilities, refining and transportation, presents a possible problem from a kashrus perspective.
Refining is the process by which crude oil is made ready to be used for human consumption by removing impurities from the crude oil.
The refining of oils involves some or all of the following steps:
- Alkali Refining: Removes fatty acid content and other impurities. This is achieved by introducing an alkali solution into the oil while it is heated.
- Bleaching: Process of removing color producing substances and further purifying the oil. This is achieved by putting material such as bleaching clay into the oil to absorb the substances.
- Deodorization: Any remaining materials in the oil that can cause spoilage or cause unpleasant odors are removed through the process. Oil is pumped into a deodorizer which is a very large piece of equipment that heats the oil in a vacuum.
All of these processes are performed hot and can be done to both animal fat and vegetable oil.
The kashering of a deodorizer is extremely difficult and is something kashrus agencies try to avoid if possible. The preference is to use vegetable oil from plants that process exclusively vegetable oils. A deodorizer is approximately six stories high. There are many trays into which oil is pumped, heated and centrifuged at temperatures as high as 700°. It is difficult to clean because after each deodorization process a film of oil adheres to the deodorizer and is not easily removed. In order to properly kasher this, every inch, nook and cranny has to be cleaned so that it looks like new, which is very labor intense.
Animal fat can be refined and processed in any of the same ways that vegetable oil is in the post crush processes. This leads us to the problem of transportation. Vegetable oil, whether it be crude, partially refined or fully refined can leave the processing plant in one of several ways.
It could be piped into the hold of a ship. This hold may have contained treif liquids which would then render the holds themselves non-kosher. This is because treif animal fats are stored while hot. It is like cooking treif fat in a pot and then using that pot to either store or cook kosher oil. Kosher vegetable oil can sometimes also be kept at temperatures considered hot. Even without the heating element, another problem would be” kavush”. Kavush takes place when a cold liquid sits in a utensil for 24 hours or more, and it by Halacha is viewed as being cooked there.
Besides the same ship holds being a problem, adjacent ship holds are a challenge too. The holds of the ship are often divided by a thin wall which poses a Halachic problem as well (see Yoreh Deah 92 regarding “Tipat Chalav”).
A third concern is the medium of heat, which often is recirculating steam. If steam that was used to heat treif animal fat is then recirculated to heat kosher vegetable oil, the kosher status of the vegetable oil will be compromised. To address these issues, Kashrus agencies have taken these steps to maintain the integrity of the kosher certified product.
- Kosher oils may only be shipped in holds that have been used exclusively for kosher products for the last three shipments.
- Adjacent holds may only contain kosher products.
- Recirculating steam must be chemically treated with a caustic like chemical which will render the steam “Pagum” (foul tasting). Something which is “Pagum” can’t make something else treif.
A Mashgiach will inspect shipping records to ascertain that our regulations have met with compliance.
Many consumers have noted that labels often indicate that food may contain trans-fat or hydrogenated oils. These two words really mean the same thing. Trans-fat is made when manufacturers add hydrogen to vegetable oil. This process is called hydrogenation. Hydrogenation increases the shelf life and flavor stability of fats containing these fats. Hydrogenated oils can be found in vegetable shortenings, margarine, crackers, cookies, pretzels and any other food made with or fried in oil. Hydrogenation presents a kashrus concern as well because tallow (cattle, sheep or horse fat) and lard (hog fat) can also be hydrogenated. Thus the commonality of equipment issue has again surfaced.
The next time you take a bit of your favorite snack food, think about all the effort of the Kashrus agency to make sure that all of the components are Kosher.