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.
A tour of South-Eastern United States with an OU Rabbinic Field Representative meeting products and people that leave a lasting impression.
An explanation of how pareve gelatin can be manufactured from beef and therefore be used in dairy products.
A discussion of the rules of Kosher sake.
A discussion of the pigeon and its status in Judaism.
A survey of the opportunities for Kosher in the country of Colombia.
A discussion of the Kosher certification of muffins.
A series of questions and answers about the Kosher status of canned salmon.
Rabbi Dovid Polsky, the remarkably patient and knowledgeable managing attendant of the OU’s ever-ringing Kosher Consumer Hotline, does not see a day go by – or even a morning — without receiving a call that touches on the overlap between kosher certification and allergen concerns.
“I see that Miller’s Heavenly Chocolate is labeled OU-pareve. Yet I also see a declaration of ‘may contain dairy.’ How could this be?”
“The soy milk I just bought states that there is no dairy or lactose in the product. And yet the kosher label says OUD. I’m confused.”
The answer to both of these questions, of course, is that although kosher and allergen considerations often converge, they are not identical.
Halacha states that milk which is produced without hashgacha (r’iyah of a Yisroel) is non-kosher; such milk is termed “cholov akum”. This rule is a gezeirah, lest milk from non-kosher animals be mixed into what otherwise could be assumed to be kosher milk. Milk is only permissible when a Yisroel watches the milking, verifying that milk from non-kosher animal species is not incorporated. (Yoreh Deah 115:1, from Maseches Avodah Zarah daf 35b)