Recycled Ingredients

A basic phenomenon in chemistry plays a crucial role in industrial kashrus. When two chemicals react with one another, one will be used up before the other. The chemical used up first is called a “limiting reactant” and the chemical which is not used up is an “excess reactant”. Often the excess reactant is recovered, purified, and used again in another production.

Fish and Meat

The Gemara Pesachim (76b) teaches that one may not cook fish and meat together since this combination is considered a sakana. Shulchan Aruch (Y.D. 116:2-3) adds that one may not even eat meat after fish or fish after meat unless one eats and drinks in between1. Rama adds that one should not cook open meat and fish in the same oven because of raicha (aroma), though bidieved we say that raicha lav milsa. Magen Avrohom (O.C. 173:1) questions whether this sakana still exists today, however the minhag is still to be machmir.

Creating Pas Yisroel

The Mishna in Avoda Zara (35b) tells us that Chazal forbade pas akum. The Gemara (36b) explains that this was done as a geder to avoid intermarriage. However Tosfos1 bring a Yerushalmi that says that a later Bes Din removed this issur. The exact extent of this retraction is a disagreement between the Mechaber and the Rama. While all agree that bread baked by an akum for personal use is still forbidden, there are differing opinions as to how careful one must be to avoid eating pas palter, bread baked by an akum for the purpose of selling.

Is Sake Kosher?

A discussion of the rules of Kosher sake.

In Times of Difficulty: A Question of Meaning, a Meditation on Kashrut

These are difficult times. Editorial pages, news and financial reporters bemoan the dramatic loss of wealth in the country and around the world. Trillions of dollars of net worth – lost. Homes – foreclosed. Businesses – shut down. Charities – struggling. Unemployment nearing record levels. Even those who have secure employment feel the anxiety. There […]

Mechiras Chametz

Mechiras chametz accomplishes two functions. It prevents the owners of the chametz from violating the issurim d’oraisah of ba’al yiraeh uba’al yimatzey and it saves the chametz from becoming chametz she’avar alav hapesach (mid’rabanan). Ideally we try to arrange all sales in the most lichatchila manner so as not only to protect the kashrus of the products but also to prevent the owners from violating issurim.

Mechiras Chametz today is typically arranged by authorizing a Rabbi to act as the legal agent on behalf of the one selling the chametz. This same procedure is utilized in regards to mechiras chametz for companies. However the question arises, who may authorize the sale of chametz on behalf of a Jewish owned company?

Mowed Lawn Aroma

A flavor, like a musical chord, is made of a set of notes. The fullness of a flavor is the result of the interplay between the numerous chemical components that constitute the flavor’s profile.

A flavorist creating a fruity flavor – let’s say, peach flavor for an ice cream –will usually need a “green” or botanical note to round out the flavor. One of the popular chemicals used by flavorists to impart “greenness” is called cis-3-hexenol. A whiff of pure cis-3-hexenol reminds one of a freshly mowed lawn.

Milui V’irui

The Gemara Avoda Zara 33a teaches us that one can kasher a barrel that was used to store non-kosher wine with milui v’irui. This is accomplished by filling the barrel with water, letting it sit for at least 24 hours, emptying the barrel, and then repeating this process two more times. There is no need for the 3 days to be consecutive.

There are two explanations in the Rishonim as to why milui v’irui is effective.

K’bolo kach polto – Some Rishonim1 understand that since the issur was absorbed through kevisha it can be purged with kevisha.

OU Kosher to Recommend Organic Certification Agency to OU Clients

As part of its practice of providing a full range of services to its certified companies, OU Kosher has announced that it will recommend Organic National & International Certifiers (ON & IC) of Lincolnwood, IL to its client companies who are seeking certification that their products are not only kosher, but organic as well.

Rice Protein Concentrate

Is rice protein concentrate derived from cooked rice? If so, rice protein concentrate is potentially bishul akum and should not be a group one.