When Koshering utensils such as forks, spoons and knives, one performs Ha’agalah by dipping them in a larger pot of boiling water to extract the Hames which is absorbed in them. There is a question whether one must wait twenty-four hours after their last use, before performing Ha’agalah. Waiting would serve to render all absorbed Hames "Pagum"-of compromised taste, which is a lower level of Kashrut problem.
Maran (452:1) rules that there is no need to wait, as long as the Ha’agalah is performed before the fifth hour on Ereb Pesah-the beginning of the prohibition of Hames. The rationale is that when the Hames absorbed in the utensil is extracted, it is one permitted taste; then, when it mingles with the boiling water, that is a second permitted taste. This forms the Halachic condition known as "N"at B"ar N"at-Noten Ta’am Bar Noten Ta’am of permitted tastes. Even if the Hames flavoring would be reabsorbed in the utensil, it has already achieved this permitted status, and there is no problem. Even Though the Peri Hadash found contradictory sources and was strict in this matter, Hacham Ovadia is lenient.
When Ha’agalah is done before the fifth hour, there is also no reason to be concerned about koshering big vessels with small ones in the same pot. Neither is there a problem if the utensils remained in the boiling water for a long time or if the water cooled down.
All of these issues would be problematic if the Ha’agalah was performed after the fifth hour.
The Mordechi brings down that one should be careful not to dip too many utensils at the same time, so that they do not become crowded and prevent the water from reaching all the surfaces at boiling point.
SUMMARY
When performing Ha’agalah before the fifth hour on Ereb Pesah, there is no need to wait twenty-four hours since their last use.
One should avoid putting many utensils at once in the vat of boiling water.
