Zevachim 97 - Can Cooking on the Next Day Remove Forbidden Flavors From the Day Before?
According to Rabbi Tarfon, if one cooked the meat of offerings in a vessel at the beginning of the festival, he may continue to cook in it the entire festival. The usual requirement of breaking or purging the vessels after the time allotted for the sacrifice does not apply here. However, the Sages say that once the time allotted for eating the sacrifice has passed, the vessel needs to be purged and rinsed.
They argue about the principle that cooking on the next day remove forbidden flavors from the previous one. Actually, they all agree to this principle, from the Torah perspective. They also agree that the Sages have forbidden this practice. In Rabbi Tarfon's view, the prohibition is relaxed for the festivals, and in the view of the Sages it is not.
Purging is done with hot water, and additional rinsing - with cold water. When two sacrifices touch and one absorbs the flavor of the other, the mixture is governed by the rules of the strictest one. This applies only to the outer layer where the flavor penetrates.
Art: Ribot Theodule - Augustin The Cook Accountant