By HaRav Shimon Anshin shlit”a
A. Hafrashas Challah (“Separating” Challah) from Kneidel Kishke:
The following is the language of the Shulchan Aruch (Yoreh Deah, 329:3): “A dough mixture that is dense and one kneads it with the foreknowledge of boiling or frying it, is exempt from “separating” Challah”.
The Shach on the other hand writes in Siman 4, that many Poskim disagree and reason that this kind of dough is also obligated in the separation of Challah. And therefore, one should be stringent in such a case to separate Challah without the Bracha (“…. le’hafrish Challah”)
Accordingly, one should be stringent in the case of kneidel kishka (made from flour) that is “cooked” in a cholent pot, and separate the Challah without saying the Bracha. (This excludes the case where it was made from Matzah Flour or pieces of bread that already had challah separated and therefore, there is no obligation to separate it again).
However, all of the above applies only when there is an amount of flour considered shiur challah (which is at least 1.050 grams) or more. Less than this amount of flour used to make dough is not obligated in the separation of Challah. (Typically this quantity of flour is used by caterers, people making a large Seuda or someone at home preparing a large amount of dough for a few Shabbasos in advance).
After the fact however, if someone did not separate Challah from the Kneidel Kishke before cooking the cholent, they should ask a Halachic authority on what to do with the food and the pot in which it was cooked.
B. Burning the separated piece of Challah:
It is a specific Mitzvah in of itself to burn the Challah that was separated from the dough.
The Rama writes near the end of Yorei Deah 322, that the minhag is to place the separated Challah in the oven to burn it before baking the dough.
There are those today that “burn” it in the oven according to the words of the Ramah.
However, “burning” it in the types of ovens we have today is in fact incorrect because the separated piece of Challah is considered “treif” in the sense that it is forbidden for use because of its holiness.
And so as such, when it comes in contact with a hot surface, its taste becomes absorbed into that surface which then attains a taste of “treif”.
What the Ramah writes about “burning in the oven”, refers to the type of oven used in those days which had open flames (similar to the ovens used today for baking Matzos) and would immediately consume the Challah and therefore no taste would be absorbed into the oven surfaces.
There are many people today that place and cover the piece for burning in aluminum foil before placing it their oven. Although this prevents the oven from becoming “treif”, it does nothing in regard to the Mitzvah of burning the separated Challah.
For those who burn it over the open flame of a gas stove, much care needs to be taken to ensure that the pieces don’t fall apart and come in contact with other food.
Therefore, if one does not have the mechanism in which to burn it over an open flame, the best way is to dispose of it by putting it inside 2 coverings (e.g. in 2 plastic bags or wrapped inside 2 napkins) and then placing it in the waste.
It is better to dispose of it this way, even though one has not performed the Mitzvah of “burning”, rather than becoming involved in a question of Issur (that which is forbidden).
If someone has in fact been “burning” the separated piece of Challah in the incorrect way as described above, they should consult with a Halachic authority on how to re-Kasher their ovens.
As this is a translation of the original Hebrew, if you are unclear on any of the Laws outlined herein in any way whatsoever, please consult with a Posek (Halachic Authority).