During Pesah we do not use the same utensils or the same dishes we use throughout the year for Hametz. Although the utensils in which we cook might be completely clean of Hametz, without any visible remaining food, the surface’s pores of these utensils absorb the flavor of the foods cooked in them. For example: if I cook meat and then in the same pot (even after I clean it) I boil eggs, the eggs would absorb some of the taste of the meat. Likewise, when we cook something in utensils used for cooking Hametz, some Hametz flavor will be reabsorbed in the food we prepare for or during Pesah.
It is customary and recommended, therefore, to have a set of dishes, plates and utensils to be used exclusively for Pesah.
When this is not possible, and especially this year under our extraordinary circumstances, we might use for Pesah the same utensils we utilize throughout the year for Hametz, after they go through a process known as hag’ala, (a kind of sterilization) to remove non visible residual Hametz that may be absorbed within the walls and pores of these utensils.
Before making the Hag’ala we need to make sure that those utensils are thoroughly cleaned of any visible of Hametz (חמץ בעין). The Hag’ala then ejects the Hametz absorbed (בלוע) in the walls of the utensil. Eliminating these adsorbed particles takes place under the same conditions the absorption of these substances occurred (כבולעו כך פולטו). The pores of a metallic surface open up when exposed to heat, and that is when absorption occurs. Consequently, the expulsion of these particles would also occur by exposing these utensils to heat.
Now, when a utensil is used throughout the year to serve or prepare cold Hametz food, it can be used during Pesah after cleaning it thoroughly from any visible rests of Hametz. These utensils don’t need to undergo the Hag’ala process since absorption of Hamatez only takes place at high temperatures. Examples of these types of utensils are: plastic cups and containers, and trays that are used mainly ( רוב שימושו) to serve cold food.
Examples of hag’ala:
Metal: Metal cutlery such as forks, spoons or knives, must be first cleaned of all visible residue of Hametz. Then, they must be immersed in a pot of boiling water. Then we wash them with cold water, and they may be used for Pesah. Hot water opens the metal pores, allowing the ejection of any absorbed Hamets. The cold water closes the pores again.
Glass: According to the Sephardic tradition, glassware, cups, plates, etc, used throughout the year for Hamets, should be washed thoroughly and can be used for Pesah without having to undergo the Hag’ala process. Glass is sterile, and it does not absorb any food substance through its pores, and therefore there is no Hametz to remove from its walls. This applies even for those glass utensils that are used at high temperatures for cooking or serving hot Hametz food.
Notice that this Halakha is very different in the Ashkenazi tradition. Some Ashkenazi rabbis like the Rama say that since glass is made from sand, glass utensils should be regarded as clay utensils, which are not susceptible to Hag’ala, and therefore cannot be used on Pesah because Hag’ala is useless for them. Other Ashkenazi Rabbis allow an Hag’ala process for glassware. Consult your community Rabbi.
Clay utensils, pottery and porcelain (Kele Heres): If these items were used for Hametz, they cannot be used for Pesah, because they are not susceptible to Hag’ala. The Rabbis explained that unlike metal or other utensils, clay utensils eliminate the substances absorbed in their walls in an erratic and inconsistent way. That is, sometimes they would expel an absorbed flavor and sometimes they will not. Because we cannot rely on the Hag’ala process to sterilize these types of utensils completely, they cannot be used for Pesah. Most contemporary rabbis believe that regular porcelain utensils should be considered of the same category as clay utensils. However, there are many other considerations to take into account which can allow for exceptions to this. Some factors which might indicate a more lenient opinion in time of need are: whether these utensils were used for cooking or for serving food; the temperature of the food served; whether the china was not used for a long time; whether it is common porcelain or glass coated, etc.
If you have further questions about this and other types of utensils that are mentioned in this brief section, please consult your community rabbi.
