What Should One Do on Pesach With a Porcelain or Enamel Sink That Cannot Be Kashered?

Question

I recently moved into a new home, and the kitchen sinks are made of porcelain rather than stainless steel. As is well known, porcelain sinks cannot be kashered. I have tried extensively to find sink inserts that would fit properly, but despite my efforts, I have not been able to locate any. I am beginning to panic. What should I do regarding using the sink on Pesach if it is not kasherable and I do not have sink inserts?

Answer

In such a case, one should proceed as follows:

1. Kasher the sink to the best of your ability: Clean the sink thoroughly and Pour boiling water over all surfaces of the sink. This is done as a stringency (chumra) to satisfy those opinions that hold porcelain is kasherable through irui kli rishon (pouring boiling water).
2. Line the sink with aluminum foil: Since we do not rely initially on the opinion that porcelain can be kashered, the sink should then be fully lined with tinfoil for the duration of Pesach.
3. Avoid soaking dishes in the sink: On Pesach, while dishes may be placed in the sink temporarily, they should not be left soaking in water. Thus, always ensure the sink is well‑drained. Do not leave vessels in the sink while water is standing in it. If necessary, dirty dishes should be placed in a basin or container on the counter, and then washed one at a time in the sink.
4. Do not pour hot water into the sink: One should not pour hot (yad soledet bo) water into the sink, especially while vessels are inside it. Either wait for the water to cool, or Mix it with cold water until it is no longer yad soledet bo.

These guidelines represent the lechatchilah (ideal) practice.

Bedievad (After the Fact)

If any or all of the above instructions were not followed, the vessels nevertheless remain kosher. This leniency applies even if:

• The sink was not kashered at all with boiling water
• The sink was not lined with tinfoil
• Vessels were left soaking in the sink water for 24 hours on Pesach
• Boiling water was poured into the sink, even while vessels were inside

Explanation

Boiling water is poured over the sink: There is a well‑known dispute among the poskim as to whether porcelain is considered a kasherable material. Practically speaking, the accepted ruling is that porcelain is not kasherable. Nevertheless, boiling water is poured over the sink [i.e. Iruiy Keli Rishon] as an added measure to account for the minority opinion that kashering may be effective. This step is performed as a stringency in order to account for those opinions that maintain that porcelain is, in fact, a kasherable material through irui kli rishon. This step is therefore viewed as a form of backup or insurance rather than a reliable solution upon which we depend initially.

Lined with aluminum foil: Following this, the sink should be completely covered and lined with aluminum foil for the duration of Pesach. This is necessary because, in practice, we do not rely initially on the opinion that porcelain can be kashered, and therefore we treat the sink as though it remains non‑kashered. Likewise, it abides by the general Pesach practice to line surfaces even after kashering. The lining serves as a barrier between the sink surface and any Pesach utensils.

Not to soak vessels in sink: During Pesach itself, although it is permitted to place vessels into the sink temporarily, one must be careful not to allow them to soak in water that is standing in the sink. The sink should always be kept well drained, and vessels should not remain inside it when water is collecting. If washing dishes is necessary, it is advisable to leave dirty dishes in a basin or similar container on the counter and then wash them individually in the sink, ensuring that they are not left soaking. The reason for this is because allowing vessels to soak in sink water could, according to the stringent opinion, cause absorbed chametz taste in the porcelain to transfer into Pesach vessels. This concern applies even though the chametz would be considered eino ben yomo, since on Pesach we are stringent even regarding non‑ben‑yomo absorption.

Pouring hot water: In addition, one should refrain from pouring hot water into the sink altogether, especially while vessels are inside it. If hot water needs to be poured in, one should either wait until it cools down or mix it with cold water until it is no longer yad soledet bo. The reason for this is because pouring boiling water into the sink could, according to the stringent opinion, cause absorbed chametz taste in the porcelain to transfer into Pesach vessels. This concern applies even though the chametz would be considered eino ben yomo, since on Pesach we are stringent even regarding non‑ben‑yomo absorption.

All of the above reflects the proper lechatchilah conduct for Pesach. Nonetheless, in this specific scenario, we are lenient after the fact even on Pesach. The reason for this is that sinks are primarily used with cold water. There is a halachic principle in the laws of Pesach that allows us, at least bediavad, to follow rov tashmisho, the majority usage. Since the predominant use of a sink is with cold water, and it was not established for hot absorption, it does not have the halachic capacity—even on Pesach—to prohibit vessels retroactively.

Sources:

See Piskeiy Teshuvos 451:11; Ohel Yaakov p. 114; Nitei Gavriel 81:1-6

See regarding the need to perform Iruiy Keli Rishon to a sink: See Admur 451:21; 46; 58 regarding tables

See regarding whether porcelain is considered a kasherable material: See Darkei Teshuvah Y.D. 121:26; Sdei Chemed Mareches Hei 30; M”B 451:163; Piskeiy Teshuvos 451:62

See regarding the issue with soaking for 24 hours – Kavush Kimivushal: Admur 447:24-25; 451:60

See regarding the issue with pouring hot water into the non-Koshered sink: Admur 451:59 regarding Minhag Nashim to not use the pot used to Kosher with Iruiy Keli Rishon due to Nitzuk Chibur; Rama Y.D. 105:3; Taaz Y.D. 105:6; P”M 105 M”Z 6; O.C. end of 452; Elya Raba 451:40; Darkei Teshuvah 105:96-100; Otzros Yerushalayim 11 p. 172; Minchas Yitzchak 5:81

See regarding the prohibition of non Ben-Yomo on Pesach: Admur 447:8; 451:33; 63; 452:19

See regarding following Rov Tashmisho: Admur 451:27-28 and 31, 33, and 72; Admur 451:27 “One is to be initially stringent, and so is the custom, and one may not swerve from the custom.”