kosher glycerin products
Reprinted from Star- K Kashrus Kurrents

In the world of food ingredients, there is no ingredient as versatile as glycerin. In the world of kosher products and kosher ingredient sensitivity, there is no kosher-sensitive ingredient that compares to glycerin. Glycerin’s ingredient versatility goes outside of food-grade applications. The pharmaceutical and cosmetic industries use glycerin extensively as a major ingredient and component in many medicines, soaps, skincare products, etc.

How is glycerin used?

Glycerin is a humectant. That means that this food chemical helps retain moisture. Therefore, glycerin is a perfect ingredient for the baking industry to keep bakery goods moist and give products a longer shelf-life. It has a sweet taste and many companies use it as a substitute for liquid sugar or sugar alcohol. These qualities also make it an excellent ingredient in chewing gum. Glycerin is an excellent solvent and is used as a mainstay for food colors. These properties make glycerin an essential ingredient in a myriad of food applications.

Furthermore, glycerin’s natural properties make it an essential ingredient in pharmaceutical products and dietary supplements. It is also a predominant ingredient across many body care products, skin care products, cosmetic products, and personal care products. What is that sweet, syrupy base used in over-the-counter cough medicine? Glycerin. What is a basic ingredient in many types of mouthwash and toothpaste? Glycerin. How about soaps, shampoos, and lotions? You guessed it … glycerin. In fact, one article lists over 1500 uses for glycerin!

In the world of kosher/non-kosher compatible ingredients, glycerin ranks #1 in the sensitivity department. Companies produce glycerin in various ways. They produce it naturally from vegetable or animal sources, or synthetically from petroleum. Kosher companies produce it as kosher or treif, and as kosher for year-round use or Kosher L’Pesach.

What is glycerin? How is it derived or produced? What makes it so kosher-sensitive?

Glycerin or glycerol is a term derived from the French word, “glycerin”, or the Greek term, “glykeros”, which means “sweet”. It is found naturally in the human body, as well as in vegetables and animals. Glycerin is a lipid. A lipid is a fat found in humans, animals, and vegetables, and glycerin is part of this lipid.

Believe it or not, the discovery of glycerin was an accident. In 1799, a pharmaceutical chemist named Carl Sheele discovered glycerin. Scheele combined olive oil with caustic soda under high heat. The result was the creation of new materials. The free fatty acids combined with sodium, creating a  “soap stock”, the basic component of soap production. This process of soap making and its byproduct is popularly known as saponification, the method used for the production of soap. The byproduct of this reaction is crude glycerin, which today is more main than a mere by-product.

Methods to Produce Glycerin

Saponification Glycerin

Sapnofication commonly uses vegetable-based products, such as olive oil, coconut oil, or palm oil. But these aren’t the only ingredients available. Saponification can also use lipids such as tallow or lard. The same result of separating animal-based triglycerides with caustic soda will result in animal soapstock and animal-based glycerin.

It is interesting to note that in the world of oil refining when crude olive or crude vegetable oil requires refining, the first stage of the refining process is “neutralization”. The solution achieves neutralization of the acidity when caustic soda combines with the unrefined oil. In this case, the caustic soda removes minimal amounts of free fatty acid that lowers the acidity but leaves the triglycerides and the glycerin in the olive oil intact. Experts say that the difference between saponification and neutralization depends upon the amount of caustic used plus the amount of heat applied to the oil. No heat plus caustic equals neutralization, and the oil remains intact. High heat and lots of caustic creates saponification, where the glycerin molecule splits off.

Transesterification Glycerin

Another method used to produce glycerin is transesterification. This involves methanol and acetic acid acting as extractives that combine with the lipid to form many components; glycerin is one of the byproducts. This process is popularly known as biodiesel extraction. Depending upon the starter material, whether vegetable or animal, the result will be either kosher or non-kosher biodiesel and kosher and non-kosher glycerin.

Years ago, there was a significant kashrus concern even with vegetable glycerin transesterification when the starter material for biodiesel productions from spent vegetable oil from McDonald’s (and other similar sources) would make non-kosher vegetable biodiesel and non-kosher glycerin. Obviously, if this spent oil biodiesel production method became cost-effective then kosher glycerin would be sold at a super-premium price, triggering further complications in the kosher glycerin market.

Synthetic Kosher Glycerin

A third method used to produce kosher glycerin is synthetical: using propylene, a petrochemical, as the starter material. Chlorination and oxidation modify the propylene molecule, which produces a glycerin molecule. This method produces viable kosher synthetic glycerin but is not cost-effective.

As we have seen, Scheele discovered glycerin as the result of an error in 1799. Today many different chemical processes produce glycerin. Amazingly, the final result is that the kosher glycerin molecule is the same regardless of the process. It is an incredible gift from the Ribono Shel Olam. Just as we learn of glycerin’s incredible application, we learn of glycerin’s potential kashrus pitfalls. For that reason, kashrus agencies have to be extremely vigilant to make sure kashrus standards are upheld on the production, transportation, and storage levels, as well as the end-user level, for a spoonful of non-kosher glycerin would be anything but “delightful” and wouldn’t go down so well!

Industrial Kosher

In the world of Kosher food and chemicals involves many complex technical ideas. The scope of Kosher Law cannot be adequately captured on one page. Industrial Kosher offers services for many businesses in Texas and across the South. This includes those in the chemical, manufacturing, transportation, and food service industries. Industrial Kosher offers teams of people who understand the in-depth, technical aspects of Kosher Laws and can help businesses navigate them. From the production of food-grade lubricants, storage, and shipment for a wide variety of products, Industrial Kosher is helping businesses find cost-efficient kosher supervision solutions. If you’re looking for more information on kosher certification in an industrial field, contact us today to learn more.