Perhaps the most powerful symbol of a non-fruit food derived directly from a tree is maple syrup.
Aside from using the maple leaf to declare its own national identity, Canada manufactures a great deal of maple syrup derived from the sap of the sugar of maple tree. Although tree sap poses no particular Kosher certification concern, the method by which it is processed may.
Maple tree sap contains sugar and other chemicals that contribute to its unique flavor. However, their concentration is too low for it to be useful as a sweetener. The sap is therefore concentrated to produce syrup, a process that involves boiling the sap for the time necessary to allow much of the water to evaporate. However, as the water is heated, small pockets of steam are created and the sticky syrup forms a coating around the pockets of vapor bubbles because of the surface tension of the syrup constituents. This undesirable side effect is called “foam,” and although these bubbles eventually break and release the vapor, the thicker the syrup, the greater the surface tension—and more the foam that is produced.
Historically, this problem was addressed by hanging a piece of pork fatback over the boiling kettle. The heat from the steam slowly melted the lard and allowed it to drip into the syrup. Just as the old adage recommends pouring oil on water to calm it, this small amount of fat is sufficient to reduce the surface tension of the syrup and thus allow the bubbles to break more quickly, solving the foaming problem but creating a Kosher certification concern.
Maple syrup processors today have generally sworn off pork, replacing it with modern antifoam agents. Antifoams are essentially mixtures of different types of silicon, glycerin, and, possibly, fatty acids (emulsifiers), and pose their own set of Kosher certification concerns. Both glycerin and fatty acids can be made from animal fats, and although antifoams are used in very small amounts, ensuring that only Kosher ingredients are used is important.
Turpentine and Oleic Acid
Other food products from the forest had more direct Kosher certification—and historical—ramifications. Colonization of the new world required a strong, well-equipped navy, and until modern times the fleet was made of wood. An adequate supply of naval stores—those products needed to keep the ships of a navy well maintained—was critical to the erstwhile projection of military superiority by the British Empire, and the pine forests of North America proved to be a treasure trove of wood rosins to make turpentine and pitch.
Although the supply of rosin may no longer herald the underpinnings of world military superiority, it does supply several interesting Kosher products. A fatty acid called oleic acid is used in many food products, including flavors and emulsifiers, and is usually derived from animal fat. Some companies now process a derivative of pine trees called tall oil (from the Old Norse thöll—young pine tree) into oleic acid, creating a Kosher source for this important raw material.
Wood Rosin and CMC
A chemical called glycerol ester of wood rosin is used in many soft drinks to allow the flavors to remain in suspension and not settle. The glycerin used in making this product may come from animal, vegetable, or petroleum sources and is therefore another wood product that requires a reliable Kosher certification. Even the wood fiber itself is processed into CMC (carboxymethylcellulose) and is used as a thickener in many food products, including ice cream, dressings, sauces, and puddings.
Wood is also a major source of sucrose (table sugar) and has played a role in both international intrigue and Halachic (Jewish Law) discourse. Sucrose is a naturally occurring sugar found in dates, sugar beets, and sugarcane.
Commercial large-scale production of sugar began in the seventeenth century with sugarcane, which became the primary crop in the Caribbean colonies of the European powers. The control of sugarcane production—and the islands that produced it—became part of the strategic balance of power among the world powers of the time, but sugar also posed a Halachic question as to its appropriate B’rachah (blessing). Tosafos (B’rachos 36b) considers sugarcane to be a tree, reasoning that it is the subject of the phrase Ya’ari im Divshi (“… my forest with my honey”) in Song of Songs (5:1); thus, the proper B’rachah for sugar is Bo’rei P’ri ha’Etz.
However, the Rambam (Hilchos B’rachos VIII:5) discusses the process for making sugar from cane and concludes that because it is made from a juice extracted from the cane, the proper B’rachah is she’Hakol. On the other hand, Rabbeinu Yonah rules that it is Bo’rei P’ri ha’Adamah. The Shulchan Aruch rules according to the Rambam, but many people consider the B’rachah for sugar to be less than a settled issue and eat it only together with other items whose B’rachah is clear.
Xylose and Xylitol
Wood is also the source of a nonsugar sweetener that is used in many candies and chewing gum. When hydrogen is attached to a molecule of sugar (hydrogenation), a sugar alcohol is created. (The suffix for an alcohol is –ol.) Sugar alcohols have properties that differ significantly from those of the sugars from which they are derived.
For example, when glucose is hydrogenated, it is converted into sorbitol, a sweetener that has fewer available calories than glucose, is safer for diabetics, and does not promote tooth decay. When xylose (wood sugar) is hydrogenated, a refreshing, low-calorie sweetener called xylitol is created. The Kashrus concern with these products stems from the fact that lactose (milk sugar) can be processed into lactitol using the same equipment, which can compromise the Kosher and/or Pareve (non-dairy) status of the xylitol and sorbitol.
Wood also serves to resolve one of the basic concerns with respect to Passover ingredients. Yeasts are microorganisms that are traditionally grown on Chometz (fermented grain), and such yeasts are prohibited on Pesach. However, yeast and yeast extract (the material found within the cell walls of yeast) are used as a nutrient in the growth of cheese cultures and as a flavoring, both of which are useful in the production of Pesach foods.
The search for a Kosher for Passover yeast finally ended with the help of the timber industry. A great deal of water is used in processing wood and paper, and much of the xylose is washed out of the wood into the processing water. A specific type of yeast called torula grows on xylose, and companies have developed yeast products and yeast extracts from torula yeast that are completely Kosher for Passover.
Another commonly used wood product is vanillin or imitation vanilla flavor. Natural vanilla is produced from the unripe fruit of one of several types of tropical climbing orchids of the genus Vanilla. The fresh fruit has no flavor or aroma. However, as the fruit is cured and dried, an enzymatic process coverts some of the natural chemicals in the fruit into vanillin. Although very popular as a flavoring agent, vanilla beans are quite expensive, and alternative sources for the active flavoring component—vanillin—have been developed.
At first, synthetic vanillin was produced by the oxidation of a chemical called eugenol, extracted from cloves purchased from the sultan of Zanzibar. With the development of the paper industry, however, scientists noted that vanillin could be produced from the eugenol and other chemicals found in the lignin, the waste material from wood pulp production. However, although wood was indeed the main source of vanillin for many years, most vanillin manufactured today is made from eugenol derived from clove oil and cinnamon leaf.
One more strategic resource from the forest also plays an interesting role in food products. Latex (or sap) from specific trees has certain desirable properties, yielding the product to which we refer as rubber.
When Santa Anna invaded Mexico in his attempt to defeat the Republic of Texas, his troops enjoyed chewing chicle, the latex of the South American sapodilla tree. We might remember the Alamo for many reasons, but one might be the introduction of chewing gum to this country. Although the Kashrus of the natural rubber poses no Kashrus concerns, the glycerin, fats, and emulsifiers used in the manufacture of chewing gum certainly do. Thus, chewing gum and bubble gum require reliable Kosher certification.
Heart of Palm
Although this text has been discussing the use of wood derivatives as foods, wood has managed to become a food itself. The Talmud (Sukkah 45b) notes a homiletic relationship between the palm tree and the Jewish people. The palm has a straight trunk without branches—figuratively configured with one “heart.” Just as it has but one “heart” so, too, do the Jewish people have but one heart for their Heavenly Father.
This heart of palm, however, has been co-opted as a specialty food that was the subject of a discussion in the Talmud itself (B’rachos 36a). The tender center of the palm trunk is harvested and eaten as a vegetable, and the question involved is the blessing appropriate to it. The Shulchan Aruch, following the conclusion of the Talmudic discussion, rules that the appropriate blessing is she’Hakol because palm trees are generally not planted with the intention of harvesting the wood food. Owing to the modern environmentalist movement, however, this position can now be questioned.
Great concern has been created over deforestation and the loss of the rainforest where these trees are grown. Consequently, producers of hearts of palm now plant and cultivate special species of palm that are particularly suited for this product and that are a renewable resource just as any other crop is. One can therefore argue that the ecological movement has succeeded in changing the B’rachah that we make for this product.
Chaza″l teach us that when Hashem (G-d) caused the earth to produce vegetation, trees were to be entirely edible; it says Etz P’ri— “fruit-tree.” The earth, however, produced trees of which only the fruit was edible— Etz O’seh P’ri—“tree producing fruit” (see Genesis 1:11 and Rashi, ibid.). The edible product of most trees is indeed limited to its fruit. As noted, however, some arboreal foods are indeed derived from the tree itself and present us with some interesting Halachic issues.
The Bottom Line
Maple syrup is produced by boiling the sap from the maple tree to evaporate much of the water and produce concentrated syrup.
Antifoams are typically used to reduce the frothing during this process, and may contain non-Kosher fats.
Kosher oleic acid may be obtained through the fractionation of tall oil from pine trees.
Glycerol ester of wood rosin is based on wood rosin and glycerin.
The glycerin component requires reliable Kosher certification.
CMC (carboxymethylcellulose) poses little Kosher certification concern.
Sugarcane is a primary source of sucrose. Xylose—wood sugar—is also used as a sweetener and may be hydrogenated into xylitol.
Torula yeast is often grown on wood liquor rich in xylose and may be Kosher for Passover.
Vanillin (imitation vanilla flavor) was traditionally produced from wood as a byproduct of the paper industry. Today, most vanillin is produced from other sources.
The original “gum” base used in chewing gum was derived from the latex sap of the chicle tree. Today, most gum base is made from synthetic rubber.
This article was authored by Rabbi Zushe Yosef Blech, Senior Kashrus Administrator of EarthKosher.