Articles

Lo Basi Ella L’orer – Cheres

February 4, 2010

In the times of Chazal, cheres was made from various baked clays. In modern times common examples of cheres include earthenware and stoneware. The Gemara Pesachim (30b) tells us that a cheres utensil cannot be kashered with hagalah התורה העידה על כלי חרס שאינו יוצא מידי דופיו לעולם. Even libun gamur is not permitted in situations where there is a concern that one might not be milaben properly for fear of cracking. Therefore, one may not kasher china by putting it through a self cleaning cycle of the oven. In such cases, the only permissible kashering is to place the utensil into a potter’s kiln which gets much hotter than libun chamur. This demonstrates that one is not concerned about potential damage.

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Lo Basi Ella L’orer – Ta’tah Gavar

February 4, 2010

When a cold item is placed onto a hot surface, Halacha tells us to view the cold item as though it were hot, even though the item remains cold. Conversely, if a hot item is placed on a cold surface, we view the hot item as becoming cooled down. However, in this case we say that until it cools down, there is a kdei klipa transfer of ta’am. This concept is brought in the Gemara Pesachim (76a) and referred to as ta’tah gavar (the bottom surface overpowers).
The Shach (92:36) brings two criteria for deciding which surface is considered the “ta’tah”.
• The bottom surface because heat rises or because the top item weighs down upon the bottom.
• The stationary surface because the item that remains in its place is considered dominant.

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Lo Basi Ella L’orer – Extended irui

February 4, 2010

Irui can only kasher the outer layer of a kli. Hot water poured against a cold kli is an example of חם לתוך צונן (hot onto cold) of which we say (Pesachim 76a) תתאה גבר ואדמיקר ליה בלע. The bottom surface succeeds in cooling down the water but not before the water succeeds in kashering the topmost layer.

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The Kosher Status of Papain

February 4, 2010

In the early twentieth century, Belgian colonists in the Congo noticed that the Congolese were careful to store elephant meat in papaya leaves. Intrigued, they found that the papaya leaves, besides protecting the meat, tenderized it. Laboratory analysis demonstrated that a particular enzyme, called papain, was the agent of the process.

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Ta’tah Gavar

January 11, 2010

Rabbi Eli Gersten
When a cold item is placed onto a hot surface, Halacha tells us to view the cold item as though it were hot, even though the item remains cold. Conversely, if a hot item is placed on a cold surface, we view the hot item as becoming cooled down. However, in this case we say that until it cools down, there is a kdei klipa transfer of ta’am. This concept is brought in the Gemara Pesachim (76a) and referred to as ta’tah gavar (the bottom surface overpowers).

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Lo Basi Ella L’orer – Extended irui

December 21, 2009

Irui can only kasher the outer layer of a kli. Hot water poured against a cold kli is an example of חם לתוך צונן (hot onto cold) of which we say (Pesachim 76a) תתאה גבר ואדמיקר ליה בלע. The bottom surface succeeds in cooling down the water but not before the water succeeds in kashering the topmost layer.

A kli rishon has the ability to be boleya and to be polet throughout its entire thickness. Therefore, one cannot kasher a kli that was used as a kli rishon with irui, even if the irui is performed with water that is significantly hotter than the temperature of the non-kosher product.

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Dairy Industry Training Webinar

November 16, 2009

On Friday October 16th the OU presented the first of a two-part webinar (Internet seminar) on dairy hashgacha. The second session took place one week later on Friday, October 23. Rabbi Yaakov Mendelson, Senior Dairy RC, moderated the sessions and presented e-mail questions sent in advance and on-the-spot by RFRs; Rabbi Avrohom Gordimer and Rabbi Avrohom Juravel responded verbally and live to the questions.

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What Beracha does one recite on a granola bar?

November 16, 2009

If one does not understand the process involved in creating a granola bar, one could study the ingredient panel a hundred times and still not be able to answer the above question. However, through our access to the companies that produce these bars we are privy to information that is important in resolving this issue.

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Lo basi Ella L’orer; Bishul Akum

November 6, 2009

Questions of bishul akum surface all the time, and it is important when reviewing products and ingredients to be mindful of the issues of bishul akum. The following are some recent issues that have been discussed in the office relating to bishul akum.

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Bitul

October 22, 2009

A summary of the OU’s position about using bitul in Kosher food productions.

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