Monday, March 27, 2006

Kosher Milk 102


The Making of Chalav Yisroel (Part 2)

Still, other milk is processed into powder, and here we will encounter issues that relate to chalav Yisrael.

In our previous article, we outlined the proper procedures for chalav Yisrael production on a farm. We discussed the rigid guidelines that the OK employs to insure that the milking, storage, and trucking are performed with Jewish oversight (“Down on the Farm: The Making of Chalav Yisrael,” April).

What happens after the milk has been sent from the farm to the dairy? Some of the milk is bottled fresh, to be sent to your local store. The milk is homogenized and pasteurized. The former is a cold process, and so no kashering is necessary if chalav stam was produced on the equipment. However, the OK insists upon kashering anyway. Pasteurization is, of course, a hot process, and the pasteurizer must be kosherized before it is used for chalav Yisrael. We will discuss pasteurization later in this article.

Other milk is processed into powder, and here we do have issues that concern chalav Yisrael. There are two kinds of milk powder: whole milk powder and skim milk powder. Whole powder is made from milk that is dried without removing any fat from it. This powder, also called full milk powder, contains approximately twenty-six percent fat. (Occasionally this powder is produced with added milk fat.) To produce skim milk powder, the fat is first removed from the milk; only the remainder is dried. Skim milk powder has a minimal amount of fat, or no fat at all.

Fat is removed from milk with a centrifuge. This ingenious device, invented in 1883 by Carl G.P. de Laval, a Swedish engineer, uses centrifugal force to spin the milk so that the cream, which is its heaviest part, sinks to the bottom. This equipment is usually not hot; it needs only a thorough cleaning from its previous chalav stam use to make it suitable for chalav Yisrael. (However, we do kosherize it.)

The removed fat does not go to waste. It is used to produce cream products such as sweet cream or sour cream, and can also be used in products such as cream cheese. This fat is also used to make butter and butter products such as butter oil (which we discussed at length in our June 1999 issue).

Kashering a Pasteurizer

When the milk arrives at the dairy from the farm, it is put into huge storage tanks. We mentioned in our previous article that such tanks sometimes store the milk for more than twenty-four hours. Therefore, they are considered kavush, and they must be kosherized. To circumvent this problem, the OK has pioneered a system to rotate the milk between tanks, so that it does not stay in any one tank for twenty-four consecutive hours.

The next piece of equipment to be used is the pasteurizer. Here the milk is heated to approximately 160° Fahrenheit. According to halachah, a utensil in which a liquid was cooked has to be kosherized using boiling water. Many of our readers have kashered a pot in their kitchen, by cooking water in it until it boils over.

However, koshering a pasteurizer is not simple, for we are presented with a unique challenge. A pasteurizer operates as a closed system. We cannot see inside when the pasteurizer is working, meaning that we cannot see the water boiling. The accepted practice among kashrus agencies is to rely upon a thermometer to measure the heat of the water.

At sea level, water boils at 212° Fahrenheit. At a higher altitude, where the air pressure is lower, water boils at a lower temperature. Some dairies are reluctant to bring the pasteurizer to a temperature of 212°, fearing that this will ruin their equipment. We are pleased that the OK’s capable staff has demonstrated to these companies that we can safely kasher a pasteurizer at boiling temperature.

Very recently we produced chalav Yisrael milk in France at a factory that initially was reluctant to permit 212° kashering. The benefit of a global kashrus presence was soon demonstrated. Rabbi Shimon Lasker, who is the OK’s European representative, contacted OK Rabbinic Coordinator Rabbi Yitzchak Ort of Milwaukee, Wisconsin, to obtain details for the proper, safe kashering procedure. (Rabbi Ort’s expertise in dairy kosher production has long been acknowledged among kashrus agencies and within the dairy industry.)

In the past we discussed this issue at length (see “How Halachah Meets Technology,” Feb. 1996). We mentioned that some kashrus agencies tend to be lenient in kashering a pasteurizer, asserting that it is impossible to get the pasteurizer to such a high temperature without causing damage. We fail to understand the basis for this leniency, and we are pleased that at its convention in May, another large organization raised its standards to insist upon kosherizing at 212° Fahrenheit. The OK remains the leader in insisting upon this standard, and we repeat the offer we have made in the past to demonstrate our technique to any company or kashrus agency that wishes to implement it.

Condensation and Drying

All milk, whether liquid or powder, is pasteurized. After pasteurization, two steps are necessary to create powder: the milk must be condensed, and it must be dried.

The condenser is a vessel that removes water from the milk via a vacuum, and it is kashered with boiling water. Interestingly, water will boil in a vacuum at less that 212° Fahrenheit, because the vacuum environment reflects a lower level of air pressure, similar to a high-altitude environment. I asked the great halachic authority Rabbi Zalman Shimon Dvorkin, of blessed memory, whether halachah requires that the water in a vacuum reach 212°. He responded that the Code of Jewish Law does not stipulate a specific temperature; it says only that the water must boil. Therefore, we do not require 212° in a condenser.

The milk then goes to be dried. There are two methods of drying the milk. One is a spray dryer, which is a large, inverted cone. The milk is sprayed in from the top and receives a blast of hot water. The water immediately evaporates. In many plants these spray dryers are used for a variety of non-kosher items along with milk. For example, we found a dairy in Switzerland where non-kosher items were being dried on the same equipment used for drying milk. Of course this poses a problem for chalav Yisrael production, but it poses the same problem even for people who use non-chalav Yisrael milk powder.

Spray dryers may be small, or they may be as tall as a six-story building; the latter are particularly difficult to kosherize. Nonetheless, we thoroughly kasher these with boiling water. At some large plants, companies run simultaneous productions of chalav Yisrael and non-chalav Yisrael. In a recent production, we arranged to separate these runs, in order to avoid a mix-up. Before the chalav Yisrael run had ended, the company started to run chalav stam. We rejected the entire one-ton production.

Another way to dry the milk is by using a roller dryer. The milk is sprayed onto a heated roller, which then dries the milk. The milk dried on the roller obtains a caramelized taste, a quality that chocolate producers prefer.

A roller dryer is heated using either regular water or water that was removed from milk in the condenser. While we generally assume that water is kosher, if the water has been used to heat non-kosher ingredients, it may be rendered not kosher. We therefore must ascertain that kosher water is being used to heat the roller dryer. Condensate — water that was removed from non-chalav Yisrael milk by a condenser — also should not be used to heat the roller dryer.

Another matter of concern is the percent of milk powder produced from the chalav Yisrael milk trucked in from the farm. Only six to ten percent of milk powder can be obtained from milk. For example, 100 gallons of milk can be condensed and dried to yield one-tenth to one-seventeenth that volume of milk powder (the former figure for whole milk, the latter for skim milk). Therefore, the supervising rabbi has to verify exactly how much milk was obtained from the farms. If the amount of milk powder produced exceeds this ratio, it would mean that the dairy has slipped in chalav stam, and the entire production would be disallowed for chalav Yisrael.

As we can see, chalav Yisrael production is no simple matter. The OK is blessed with a number of experts in all phases of the process, and consumers can purchase OK-certified chalav Yisrael products with confidence that they were made with complete fidelity to the laws of kashrus.


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