Answers to Common Kashrut Questions
Eating in anything but a supervised kosher restaurant can be fraught with problems and could even result in non-kosher food being consumed. Even if one were only to order fish, there are of course many varieties of fish that are not kosher. Fish stock made from non kosher fish could also be used to flavour kosher fish. In a regular restaurant it is also not unknown for vegetable soups to be boosted with the chef's stock or bouillon containing all sorts of non-kosher meat and bones.
Most processed foods and ingredients nowadays contain food chemicals such as emulsifiers E471, glycerol monostearate, calcium stearate, gelatine and many others all of which often have an animal origin. Customers are often unaware of these ingredients which could be used in vegetarian dishes.
Many vegetables also require checking for infestation since their consumption is strictly forbidden according to Torah law. At a kosher restaurant, a kosher supervisor will spend many hours checking all the vegetables used. A non-kosher restaurant may serve the vegetables with much of the insect life still present if not actually alive and kicking!
At both a 'kosher style' and vegetarian restaurant the pots and pans being used may well have had non-kosher food cooked in them at some point. A well known principle in Kashrut, borne out by scientific evidence, is that utensils absorb and exude previous substances cooked in them.
A further problem is that ordinary wine, wine vinegar, cheese and cheese derivatives are all strictly prohibited in Rabbinic law. The inclusion of any such items would make a "kosher-style" or vegetarian meal thoroughly non-kosher!
Finally, true kosher cuisine requires Bishul Yisrael - some "jewish input" to the cooking, for example, that all cooking equipment has been switched on by a Jew. This of course will only happen at a supervised kosher restaurant.
