When kashering utensils (for פסח) in a boiling pot of water, is there a certain amount of time (seconds) the utensil needs to be kept under water. Or, could it be a speedy dip in and out. (Is there a לכתחילה and a בדיעבד ) Thanks!
The poskim say that the utensils should be left inside the water long enough for the absorbed taste to get purged out of the utensil. It isn’t clear though exactly how long this is. There are differant opinions ranging rom a few seconds to half a minute. See sources.
Taz O:CH 452-2, Eliyahi Rabba O:CH 452-1, The Kosher Kitchen chapter 14 ftnt. 126, the Jewish Kitchen pg. 75, Daf Hakashrus 22-8 ( pg. 22), Halachos of Pesach ( R’ Eider) pg. 152, Chut Shami ( Pesach) 11-1.