In recent generations, new storage methods have been introduced that allow us to preserve food products for long periods of time. As a result, food manufacturers and dealers are in constant possession of large inventories of food, and they need to sell their ĥametz before Pesaĥ in order not to lose the value of their stock. Moreover, if food manufacturers were to make a point of exhausting their entire inventory before Pesaĥ, it would take days and even weeks to restock and market their products, and in the mean time, they would lose business. Even if no competitors were to seize the opportunity, it would cause a great inconvenience to buyers, who would be unable to purchase ĥametz foods during the weeks after Pesaĥ. Therefore, factory owners, food chains, and stores sell all of their ĥametz to a gentile before Pesaĥ, and as soon as Pesaĥ passes, they buy it back again and remarket it.
In principle, anyone may sell his ĥametz to a gentile via the mekhirat ĥametz organized by his local rabbis. He may do so even if he only wishes to sell a small amount of ĥametz – for example, a package of pasta – because once it has been sold, the Jew no longer violates the prohibitions relating to ĥametz.
Some are stringent and prefer not to rely on mekhirat ĥametz since it appears fictitious: the ĥametz remains in the Jew’s house, the gentile will almost certainly not come to take it, and the Jew resumes eating the very same ĥametz as soon as Pesaĥ is over. According to these poskim, it is only possible to sell ĥametz in order to prevent a great loss; concerning a small loss, one should not sell his ĥametz, in order to avoid possible transgression.
Nowadays, all are advised to participate in mekhirat ĥametz, because some food products and flavored medicines may contain small amounts of ĥametz, and they should not be destroyed just because of this possibility. On the other hand, these must not be kept because they may actually contain ĥametz. Therefore, to avoid all doubt, the best thing to do is to sell them.
Concerning ĥametz gamur, people are advised not to sell insignificant amounts of ĥametz, so as not to use the mekhirat ĥametz for small needs. However, when a significant loss is involved, it is permitted, even le-khatĥila, to sell the ĥametz. Each individual should decide for himself what he considers a significant or small loss. Nonetheless, one is permitted to sell his ĥametz even if he only wants to prevent a small loss, for mekhirat ĥametz is fundamentally halakhically valid, and one may be confident that the rabbis conducting the sale do so in full compliance with halakha.
Because the sold ĥametz remains in the Jew’s house, there is a risk that he will forget that it is prohibited and eat it during Pesaĥ. Therefore, one must set up a partition at least ten tefaĥim high (80 cm) to act as a barrier between himself and the ĥametz, or lock the ĥametz in a cupboard and hide the key. One may also tape up the cupboard. It is advisable to write “sold ĥametz” on it so that one does not accidentally open it on Pesaĥ (see SA 440:2).
. Sidur Pesaĥ Ke-hilkhato 11:5 states that there are those who maintain that one who has money invested directly or indirectly in stock of companies that produce ĥametz must sell these shares before Pesaĥ. Consequently, all ĥametz sale documents include clauses regarding stocks and shares in these types of companies. However, according to the letter of the law, if one does not have any decision-making power in the company, he is considered a creditor, not a partner, and he would not be required to sell his shares, as explained above in 3:3. Thus, one who sells his shares in this particular company does so merely to satisfy all opinions. Above at 4:11 we cited a dispute between poskim regarding whether or not one can exempt himself from bedikat ĥametz by selling his home to a gentile. According to all opinions, however, if the Jewish owner leaves one room in the house for himself, he can perform bedikat ĥametz in that room and exempt himself from bedikat ĥametz in the rest of the house. Bedikat Ĥametz U-vi’uro 8:17 states that in addition to bitul, one should sell all of the ĥametz in his possession, since if he was unaware of a certain piece of ĥametz during the time of nullification and did not nullify it properly, the ĥametz sale will certainly protect him from violating any prohibition. Even though he sold his ĥametz, if he finds the ĥametz on Pesaĥ he is permitted to burn it. This is not considered stealing from the gentile, since he is not causing the gentile any monetary loss. However, it seems to me that it is better not to sell all the ĥametz that one has in his possession, since this makes the whole sale look fictitious, because every buyer wants to know where his purchase is without having to look for it all over the house. Therefore, one must decide where to place his ĥametz, and it is preferable to specify the location in the authorization contract. Regarding ĥametz that may have remained in the house, bitul is sufficient.
. Hilkhot Ĥag Be-ĥag 10:14 and 11:9 and in the notes states that the sale of ĥametz gamur should be limited to owners of large businesses, but individuals must take care, as much as possible, to only sell uncertain ĥametz. So states Bedikat Ĥametz U-vi’uro 8:9.
According to the letter of the law, every individual has the right to rely on the sale, since the sale is valid according to the majority of poskim. Even if the seller feels that the sale is somewhat fictitious, if the gentile wishes to do so, he could take the seller to court and legally claim the purchased ĥametz, which proves that the ĥametz indeed belongs to the gentile. Additionally, since every person nullifies his ĥametz, and subsequently there is no Torah prohibition on this ĥametz (there is only a rabbinic injunction that requires destroying or selling the ĥametz in addition to bitul), the ĥametz assumes the status of a safek de-rabanan (an uncertainly about a rabbinic prohibition). Thus, one may certainly rely on the lenient opinions that permit the sale.