We now come to Mishnah 12 in chapter 10 of Maseches Terumos - the final mishnah of the chapter, and the last in the series of mishnayos dealing with cooking and the transfer of flavors. This mishnah concerns eggs and the liquids left over from boiling and pickling.
The eggshell as a porous body:
Chazal understood that an eggshell is porous. Therefore, an egg cooked in a liquid containing forbidden spices - spices of Terumah, of orlah, and the like - absorbs the forbidden flavor through its shell, and the entire egg becomes forbidden.
"Afilu chelmon shelah asur":
The mishnah teaches that the prohibition does not stop at the outer layer, but penetrates to the very depths of the egg:
The white - the white portion of the egg, which lies next to the shell.
The yolk - the yellow portion, which is located deeper inside.
Even though the yolk sits deep within the egg, it too becomes forbidden, since the egg is porous and the flavor is absorbed throughout it.
Mei shelakos and mei kevashim:
"Mishlakos" - the liquid that remains after vegetables have been boiled, that is, cooked well beyond the usual measure.
"Mei kevashim" - the liquid in which vegetables were pickled, such as the brine left in a jar of pickles after the pickles have been removed from it.
If the vegetables that were boiled in the pot or pickled in the jar were Terumah, the liquid that remains is "asur lezarim" - it has the status of Terumah, and anyone who is not a kohen may not eat it, since the flavor of the vegetable that was cooked or pickled in it has been absorbed into it.
In summary: In this mishnah we learned two laws regarding the transfer of flavors: an egg cooked in a liquid containing forbidden spices becomes entirely forbidden, even its inner yolk, because of the porousness of the shell; and the boiling water and pickling brine of Terumah vegetables are forbidden to non-kohanim, because of the flavor of the vegetable that was absorbed into them.