Kosher Australia

by Rose Mehlman

Just before Chanukah my son Yirmi told me about his visit to an olive grove and crushing plant near Rehovot, Israel. The owners keep all the agricultural laws: trumot, ma’aserot, orlah and shmittah, to ensure that the olives are kosher. He and the other yeshiva bochrim picked thousands of olives and then waited for them to be crushed. The resulting cold pressed oil was to be used for their menorahs. This was a reminder of, and as close as one can get today, to the pure olive oil which was used to rededicate the Beit Hamikdash by the Maccabim and miraculously burned for eight days.

Oils are a component of many different plants and are used widely in foods, flavours, perfumes, cosmetics, medicines and aromatherapy. There are many different methods of extracting oils, depending on the nature of the plant and how much oil it contains. Like olives, the skins of citrus fruits can be cold pressed since they contain a high percentage of oil. In a fruit juicing plant all parts of the fruits are used. After the fruit is squeezed for the juice, the remaining skins are crushed for the oil. The oil and water mix is centrifuged to separate off the oil. These oils are a relatively cheap form of flavouring and are used throughout the food industry.

Grains and seeds require a more complex treatment to extract the oils. The grains and seeds are heat treated and rolled to soften the outer husk and then extract the first crude oil. The crushed pulp, called cake, is then treated again with a solvent, hexane, to extract the remaining oil, and the solvent is evaporated off again and reused. The crude oil from both these pathways is treated to remove phosphatides, gums and other undesirable components. The crude oil is transported to a refinery for deodorisation and decolourisation. The resulting oil is a stable product with a desirable taste and smell.

To be able to kosher certify these oils, all additives must be acceptable, transport must meet kosher requirements, and the refinery should be dedicated to vegetable oils. If tallow is also refined on the same equipment, a proper kashering must take place, which is very difficult to accomplish. Kosher Australia certifies many of the vegetable oil companies in Australia. The more delicate oils from vegetables, berries, leaves and flowers can be extracted either through steam distillation or by solvent extraction. Tasmania, because of its pristine natural environment, is very suited to growing high quality produce from which the finest essential oils, can be derived. These are used as flavours, perfumes, and for their therapeutic properties, in cosmetics, neutraceuticals and aromatherapy. Kosher Australia certifies one of the major essential oil manufacturers in Tasmania. A number of years ago I visited both the farms and the blending facility for this company. There is a visit to the farms every second or third year. We spent half the day bumping over paddocks from one farm to the next, inspecting their oil extraction methods. (The ‘greatest challenge’ was elegantly negotiating the really tall step of the four wheel drive.) On these farms dill, parsley, fennel and peppermint are extracted through steam distillation. A small ramshackle hut on the farm houses the boiler, which blows steam through a vessel containing the chopped leaves. The aromatic oils are released by the heat and carried by the steam into a condenser which liquefies the steam again. When the liquid settles, the oil rises to the top and is decanted into barrels.

These essential oils are transported to a laboratory in Hobart, to be blended to the correct taste profile. The blending facility is audited annually. I learned that, for peppermint oil, for instance, the taste comes from over 200 different chemicals acting together on the tongue. Depending on the time of year, and even time of day of the harvest, there will be a different balance of chemicals in each barrel producing a slightly different taste profile. Using gas chromatography to assess each barrel, the oils are then blended to consistently achieve the peppermint taste that Darrell Lea wants or a slightly different taste that a chewing gum manufacturer needs.

As well as steam distilled essential oils, this company also extracts oils using solvents. Tasmania has many native shrubs that produce interesting and intense flavours. My guide took me into the nearby hills and showed me native boronia bushes nestling between the boulders. Initially these wildflowers were gathered to produce the citrus enhancing flavours, but now the wild boronia is grown commercially. They also extract flavours from the fruit buds of the blackcurrant bush and pepper-like flavour from the leaves of the Tasmanian native pepper shrub. The solvent method of extraction is in two parts. First the leaves or flowers are soaked in a solvent like hexane or CO2 under pressure, into which the oils and waxes dissolve. The solvent is then removed by gentle heat. The remaining solid mass is called a concrete. This is stirred with alcohol to dissolve the aromatic compounds and the alcohol is evaporated off. What remains is called an absolute, and is quite a concentrated form of aromatic oil. Generally, the only kashrut issues are the ethanol and perhaps the boiler chemicals used in steam distillation. There are usually no problems.

As I look at my oil lights burning on the eighth night of Chanukah, I sense the miracles that happened then. But I also think of the everyday miracles we take for granted. One of them is oil, hidden within so much of the plant kingdom, available to us, and providing multiple benefits.