One of the most commonly asked questions in the Kashrus world is: "Why can't I look at the ingredient list of a food to determine if it is Kosher?"  Since most modern processed foods bear an "ingredient statement", a legally mandated list of the ingredients used in its production, one may often wonder if this information is sufficient in making a Kashrus determination.  In truth, there are many reasons why the true Kosherstatus of a product cannot be divined from reading the ingredient list.   First, while many ingredients may be derived from both Kosher and non-Kosher sources, their sources are not obvious from the legal name of the ingredient.  Second, the Kosherstatus of a food depends not only on the ingredients but the equipment on which it is produced.  A third reason is that certain "minor" ingredients need not be listed at all - even if their use would indeed compromise the Kosherstatus of a product. And fourth, the nomenclature used in ingredient declarations often obscures the true nature of ingredient and its potential Kashrus implications.  Generic names such as "emulsifiers" and "stabilizers" may sound innocuous, but their Kashrus implications are far from harmless.  The purpose of this article is to offer the reader an understanding of some of the Kashrus issues relating to these hidden ingredients that blend so seamlessly into the foods we eat. 

Many of the foods we eat contain mixtures of different types of liquids. Often, these liquids tend to separate even after they have been mixed well - such as when blending vinegar and oil to make salad dressing.  It was observed, however, that under certain circumstances the repulsion of such liquids from each other could be overcome.  It was long noted that milk contained a certain amount of fat, and indeed that fat did tend to separate after a period of time. Those who remember milk before the days of homogenization will recall that when a bottle of milk was delivered to the home, a layer of cream had floated to the top.  However, the milk and cream were originally mixed together when the milk came out of the cow, and by simple mixing they could be recombined, albeit not permanently. The term emulsion - from the Latin emulgere (milk) - was coined to describe this phenomenon.  It was later understood that milk contains a number of natural emulsifying agents, and as science began to understand the nature of these chemicals, many types of emulsifiers were developed to address a varied list of food and chemical requirements.  Today, we augment these natural emulsifiers by homogenizing milk, which involves breaking the oil droplets into such small particles that they can remain suspended much longer in the milk without separating.

The problem with mixing oil and water is that each liquid tends to attract molecules that are similar to it and repel those that are different.  Fats are part of a category of chemicals called esters, complex chemicals produced by the reaction of an acid and an alcohol. [The term was coined by the German chemist Gmelin as a contraction of the German Essig (vinegar) and Äther (ether).]  In the case of a fat, this ester is composed of fatty acids and glycerol (glycerin), and is known as a tri-glyceride. The structure of this ester is non-polar, which means that electrical charges are evenly distributed. Water, on the other hand, is polar, which means that some positive and negative charge is always found separated, with the positive at the two ends and the negative in the "middle" of the molecule. Therefore, when oil and water are mixed, they quickly separate.  It was long recognized, however, that fats could be treated with chemicals to allow them to mix with water - the process used to make soap - a classic emulsifier.  In this process, lye (sodium hydroxide),creates a mixture that is predominantly sodium stearate (soap) and glycerin.  One end of the soap molecule is attracted to water (hydrophilic, water loving), while the other is attracted to oil (lyphophilic, fat loving, or hydrophobic, water hating).  By providing a bridge between the two materials, both the oil and the water can remain mixed together. Food emulsifiers function in essentially the same way. 

The French arguably gave us one of the earliest applications of the use of natural food emulsifiers.  Mayonnaise is a blend of vinegar (acetic acid and water) and oil, a trick that seems to defy the conventional rules regarding the mixing of oil and water.  However, necessity is the mother of invention - in this case, the use of lecithin (and cholesterol) as an emulsifier.  The story is told that, in 1756, the French chef of the Duke of Richelieu was preparing a victory feast to celebrate his master's defeat of the British at Port Mahon. His creation called for a sauce made of cream and eggs, but realizing that he had no cream in the kitchen, he improvised - substituting olive oil for the cream. A new culinary masterpiece was born, and the chef named it "Mahonnaise" in honor of the Duke's victory.  While he succeeded in keeping the vinegar and oil mixed together, he probably did not realize that it was the lecithin and cholesterol in the eggs that allowed this feat to be accomplished.  Lecithin is an ester of glycerol with one of the fatty acids ending with a phosphoric acid derivative, and also attracts both fat and water. Cholesterol is a complex molecule that has both hydrophilic and lypophillicaspects. Both attract both fat and water, i.e., they function as emulsifiers.  Although mayonnaise continues to be made with egg yolks, virtually all of the lecithin used as a food emulsifier in other food products comes from soybeans.  Soybeans are inherently Kosher. However, fatty acids are often added to lecithin to improve its consistency, so the source of these fatty acids is a major Kashrus concern. Lecithin can also be treated with certain enzymes to enhance some of its properties, and such enzymes are often derived from non-Kosher animal tissue.  An additional concern relates to Pesach. Many foods - notably chocolate and margarine - use lecithin as an emulsifier, and so such products must be reformulated for Pesach use.

Another major category of emulsifiers is called monoglycerides. Fat molecules (tri-glycerides) are composed of three fatty acids connected to one molecule of glycerin.  A monoglyceride is produced by splitting off one of these fatty acids and combining it with another molecule of glycerin. Monoglycerides are excellent emulsifiers, and may be used alone, further reacted with other chemicals, or used in combination with other emulsifiers to achieve the desired results.  [The di-glycerides that are a by-product of this process have no active emulsification properties, and may be left in the product - creating a product called mono and  di-glycerides- or removed to leave purified distilled monoglycerides]. In addition to emulsifying oil and water, mono and di-glycerides offer an additional advantage to the food industry. Although these products are derived from fat, due to a quirk in labeling law, they are no longer considered fats, and foods that contain them may be labeled "fat free".    

The production of this type of emulsifier poses a number of Kashrus concerns. First, the source of the original fat must be Kosher. Unfortunately, animal fat is often significantly less expensive than vegetable fat, and both will produce an equally functional monoglyceride.  As such, there is an economic incentive to use animal-based monoglycerides - especially since the animal-based version may be added to an "all vegetable" product without being declared as animal derived.  (These emulsifiers are permitted in 100% vegetable oil without further labeling.) In addition, even if all of the ingredients of a given emulsifier are vegetable based, many emulsifier manufacturers produce both animal and vegetable based versions on the same equipment.  As such, these facilities require careful cleaning and Kashering in order to produce Kosherproducts. An additional concern stems from the glycerin that is added to produce such emulsifiers.  Synthetic glycerin is produced from petroleum, and poses no inherent Kashrus concern. However, as we noted in the description of the production of soap, the splitting of a tri-glyceride results in the production of glycerin, and much glycerin is produced from both animal and vegetable fat sources.   Care must therefore be taken that the glycerin used in the production of Kosheremulsifiers comes from Kosher sources.

Certain emulsifiers have additional properties in food production in addition to allowing the mixing of oil and water.  Monoglycerides can be reacted (esterified) with tartaric acid to produce a chemical called DATEM that reacts with both starch and protein, and is especially useful in the production of bread.  By binding with these components of flour, it allows for easier processing of the dough and for the dough to rise better.  In addition to the Kashrus concerns raised with the monoglyceride component, tartaric acid poses an additional area of potential concern.  Tartaric acid has historically been derived from the sediment that crystallizes in wine casks in the form of argol, which remains the major commercial source for this chemical.  Virtually all such tartaric acid is produced from non-Kosher wine and grape juice, raising a question as to its Kosherstatus. The Halachos relating to wine, however, are somewhat unique, and the Shulchan Aruch (Y.D. 123:17) indeed rules that since the argols are dried for 12 months and bear no resemblance to wine, they have the Halachik status of earth and are permitted.  It should be noted, however, that the permissibility of tartaric acid produced today may not be as clear.  First, it should be noted this opinion is not universally accepted (see Darkei Teshuva ibid.).  Second, virtually none of tartaric acid produced today is actually dried for 12 months - modern heat treatment is used to accelerate the drying process, the impact of this processing change is debated amongst the Poskim.  Third, a new process for extracting tartaric acid from fresh grape juice has been developed, further complicating the Halachik picture for tartaric acid.  Suffice it to say that the Kosherstatus of DATEM, even when made from vegetable monoglycerides, is not universally accepted.

Another emulsifier commonly used in the baking industry is called SSL - Sodium Stearoyl-2-Lactate, which is produced from lactic and stearic acids, plus other chemicals.  By binding to starch, it has the ability to retard the staling process in baked goods thus increasing their shelf life.  While the lactic acid poses no dairy concerns (it is produced through the fermentation of various types of sugars, and should not be confused with its linguistic cousin "lactose"), the source of the stearic acid is a significant issue. Stearic acid is a fatty acid produced by splitting fat molecules, and even if the fat itself is Kosher, if the facility also processes animal fats, care must be taken that the equipment on which it is produced is properly Kasheredfrom non-Kosher fatty acid production. 

Another common class of emulsifiers arecalled Polysorbates, which are produced by the esterification of sorbitol and a fatty acid.  In addition to the Kashrus concerns regarding the status of the fatty acids, the use of sorbitol opens new vistas in the Kashrus concerns regarding emulsifiers.   Sorbitol is produced by the hydrogenation of glucose, and generally poses no year-round Kashrus concerns. Pesach, however, is another story. Glucose may be derived from corn (Kitniyos), and is generally forbidden to Ashkenazik Jews during Pesach.  However, at least one major Kashrus organization has taken the position that the esterification process serves to change the status of sorbitol to such an extent that it is no longer considered Kitniyos. A greater concern, however, stems from the use of polysorbates that are produced in Europe, where much of the sorbitol is produced from wheat starch and is true Chometz.  While Kitniyos polysorbates may be owned and used on Pesach, those that contain true Chometz are completely forbidden.

In discussing the holiday of Purim, the Talmud offers us an insight into the nature of the miracle itself.   It notes that the peril in which the Jews found themselves - as well as their ultimate salvation - was orchestrated by Hashem under the aegis of the natural order - a sort of "behind the scenes" operation.   A certain level of improper behavior by the Jewish people caused Hashem to punish them by obscuring His divine protection - hence the mnemonic allusion of Esther - "hidden". The Talmud therefore ascribes the verse ????? ???? ????? ??? - "I will hide my countenance" - to the miracle of Purim, and upon their Teshuva, Hashem returned the Jewish people to safety through behind the scenes political machinations. In celebrating the holiday of Purim, we declare that we indeed recognize that it is Hashem's hand that guides all facets of our lives, even if they are not readily discernible to the naked eye.  In Kashrus, we are often faced with the same test, and whether it bewith Esther or ester, we take the same care to understand what is really behind the scenes.