Hello,
I understand that using the same oil that was used to cook something non Kosher, to cook something Kosher in the same frying pan its a big concern, but, when we are talking of big fryers, taking into consideration that sometimes the food is breaded (and the amount of oil), the flavor it may pass from one food to another isn’t completely batel?
Thank you for your explanation.
The reason for the question is indeed related to fries, for example, that usually are one of the only items you can have when hanging out in certain places with friends or when on a rush and you want a snack from a fast food chain.
Long before I learned more about the details of Kashrut, flavor, batel, etc. My logic, common sense and what I knew from previous learning told me that it is rarely an issue and I used to order fries from establishments (obviously I’m talking about clean places), mozzarella sticks, Baja style fish tacos, fish and chips and similar items with Kosher ingredients, always asking about the type of oil used. I never tasted any trace of chicken, meat or seafood even though sometimes they told me that they used the fryers for such items as well (usually the constant use is more with pareve items). In the place I live we don’t have unfortunately Kosher restaurants, so, can I continue with such practice with no concerns? Obviously I wouldn’t order any fried item from places that certainly look unclean or messy.
When it comes to large commercial fryers, halachically the issue is often less severe than people think. If the oil is vegetable-based and not something like tallow, and the fryer is used for different foods on different days, the taste of meat or chicken rarely carries over. The huge volume of oil and the long cooking times usually destroy any trace flavor.
From a strict halachic perspective, if you cannot taste the meat flavor in your fries, the food is permitted. You could even ask the staff if you’d taste chicken in your fries — almost always, the answer will be no.
That said, I personally don’t recommend relying on it if you can avoid it. Sometimes the flavor does linger, especially right after frying meat or chicken. If you’re in a situation where you have no other food, and you confirm that the fryer is used mainly for pareve items and not right after cooking meat, halacha would allow you to eat it.