Food Adulteration

By Mordy Hoenders posted October 27, 2016

As far back as the time of the Mishnah, Chazal were concerned about the adulteration of food and how this affected its Kosher status. For example, in Chazal’s times non-Kosher milk was added to Kosher milk to increase the liquid volume. They therefore instituted a decree of a Jew being present at the milking to ensure the Kosher integrity of milk. In recent years, we have heard many reports about food fraud and adulteration (often economically motivated (1)). An example of this is the European horsemeat scandal in 2013. Other foods which have been adulterated in recent times include honey, fish, extra virgin olive oil, coconut oil, fruit juices and spices like saffron and oregano. For the purpose of this article, I would like to discuss the adulteration of honey, extra virgin olive oil and oregano.


The Mishnah (Bechoros 7a) teaches that “what comes from a non-Kosher animal is not Kosher”, for example eggs from non-Kosher birds are not Kosher and milk from a non-Kosher animal is not Kosher. Honey, however, is considered Kosher by Chazal even though a bee is not. The reason is disputed. The first opinion is that honey is Kosher because it is simply nectar passing though the bee’s body (like urine which comprises of water coming in and going out of the body) and is not a secretion. The second reason that honey is Kosher is because we learn it from a pasuk in Vayikra. Wasp honey on the other hand is not uniformly considered Kosher (2) because the second opinion, where honey is considered Kosher due to the pasuk in Vayikra, would not cover wasp honey. The word ‘honey’ without further specification is considered as bee honey. The Rabbis, however, were not concerned about mixtures of non-Kosher wasp honey and bee’s honey because wasp honey is very uncommon. They therefore did not require verification about the source of the honey (3). This was in contrast with mixtures of Kosher and non-Kosher milk, which was more common, hence the gezeirah of Cholov Yisroel (4).

[update 28 Oct 2016: Food standards define honey as "the natural sweet substance produced by honey bees from the nectar of blossoms or from secretions of living parts of plants or excretions of plant sucking insects on the living parts of plants, which honey bees collect, transform and combine with specific substances of their own, store and leave in the honey comb to ripen and mature." The latter type is also know as honeydew honey and a fascinating discussion about the kosher status for honeydew honey can be read at page 18 in a kof-k article by Rabbi A Senter.]

Another concern is the Passover status of honey. Pure honey does not possess any Passover concern, but adulteration of honey with sugar from cane, sugar beet, corn, glucose (possibly from wheat) or other sweeteners does happen in the honey industry and therefore can render it non-Kosher for Passover. The honey industry uses a fascinating test to detect honey adulteration (5). In short, sugar molecules contain carbon, hydrogen and oxygen atoms. Each atom is built up from even smaller particles. Within a type of atom, like carbon for example, there exists slight variations in the particles building up the atoms, resulting in so called isotopes.

Sugar molecules are created from smaller molecules due to chemical reactions in plants. Each type of plant will create the sugar molecule using a different chemical reaction. The chemical reactions act over time as a sieve in that they have a preference for certain carbon isotopes (6). As a result, the distribution of carbon isotopes in the sugar molecule differs depending on which type of plant made the sugar molecule. The distribution can be measured in a laboratory and it's possible to distinguish the source (type of plant) of sugar molecules with identical chemical structures. Skew of the isotope distribution is an indication of adulteration of honey with cane sugar, sugar beet or corn. As far as I know, honey that is imported and exported into/from Australia is subject to this expensive testing performed by a few commercial laboratories around the world.

Extra Virgin Olive Oil

Production of Extra Virgin Olive Oil is straightforward. The oil is made by pressing olives within 24 hours from harvesting. The olives are washed and mashed. A water/oil mixture is separated from the fruit, and finally the oil is separated from the water. This Extra Virgin Olive Oil is stored in tanks to allow sediments to settle and is bottled later on. Based on this, one would be able to buy Extra Virgin Olive Oil without rabbinic supervision.

In Australia, the trees are (for economic reasons) harvested once per season, leaving the unripe olives on the tree, while in Europe it is common to harvest two or three times per season to collect the olives which ripen later as well. The quality of the oil made from the second or third harvest is not the same as the first harvest. These lower quality oils can be refined in factories processing tallow and mixed back in the ‘Extra Virgin Olive Oil’ to improve the texture. This mixture is sometimes sold as ‘Extra Virgin Olive Oil’. Alternatively, other oils (including soy, canola, sunflower and nut oils) can also be mixed into the ‘Extra Virgin Olive Oil’. Both scenarios could compromise the Kosher status of the product.

The OU has addressed the above concerns regarding Extra Virgin Olive Oil (7). They found out that in the US all major olive oil brands monitor the competition closely for adulteration of Extra Virgin Olive Oil. Therefore, the OU holds one can safely buy Extra Virgin Olive Oil in the US from a major brand as these are ‘regulated by the competition’. Other brands require supervision. The Australian Olive Oil Association conducted a test a few years ago on imported Extra Virgin Olive Oil and found not all complying to the label ‘Extra Virgin Olive Oil’. Since then they have been lobbying for stricter regulations to protect the Australian Extra Virgin Olive Oil producers from unfair competition. As a result, Kosher Australia removed its recommendation - ‘imported Extra Virgin Olive Oil from Europe is acceptable without supervision’ (8).

Dutch Consumer Affairs reported in August 2016 that 11% of tested Oregano sold in The Netherlands showed ‘irregularities’. An Australian newspaper reported at the beginning of 2016 about ‘Oregano mixed with olive leaf without declaration on the ingredient label’ being sold in Australia. One of the reported brands was Kosher certified by Kosher Australia. Kosher Australia was asked how we could certify an adulterated oregano product as ‘Mehadrin’, when it was found to be contaminated.

It’s important to understand why Kosher agencies have no concern that oregano sold as pure oregano is being adulterated with other leaves (putting aside the question about
Geneivas Daas which is another matter). This is due to two factors: 1) Even if they are being contaminated, the contaminating ingredient is highly unlikely to be not Kosher, i.e. olive leaves, and; 2) The likelihood of this occurring is very small and the Rabbis do not want the burden the manufacturers and Kosher consumers with special supervised Oregano. Consequently, if an ingredient is officially labelled as pure Oregano, we accept this without further research.

1., retrieved 30 August 2016
2. Y.D. 81:9, Pri Chodosh
3. Y.D. 81:9
4., retrieved 20 August 2016
5. Isotope ratio mass spectroscopy
6. Kinetic isotope fractionation
7. The Daf HaKashrus Consumer Edition Chanukah 5775
8. The change in wording was made before Chanukah 5775