You are standing in front of the Kosher for Passover shelves looking for the kasher lePesach stamp of approval on the Coca Cola bottle. Your friend is frowning at the cap on the seltzer bottle, trying to decipher the kasher lePesach stamp. The glatt shop is closed and the Maxwell House coffee in the supermarket has no Pesach stamp. Your son, who is back from yeshiva in Israel, refuses to take home table salt without a kasher lePesach stamp. And somebody told you paper plates have starch. Short of hiring an escort mashgiach, what do you do?
A few background principles regarding the prohibitions of chametz mixtures on Pesach might provide some shopping guidance.
During the rest of the year, when forbidden food gets mixed up with permitted food, the mixture may be eaten if the ratio of the permitted food to the forbidden food is a certain prescribed amount and certain other conditions are met. Thus, if a piece of cold non‑kosher meat got mixed up with two cold pieces of kosher meat, all three pieces may be eaten. This permission is based on the halachic principal according to which the majority nullifies the minority – bitul berov. Accordingly, it may be presumed that each piece of meat consumed belonged to the kosher majority. If the non‑kosher piece of meat were cooked in a pot containing kosher meat, and the ratio of the kosher meat to the non‑kosher meat were 60:1 (batel beshishim), the whole mixture, including the non‑kosher meat, may be eaten.
These permitting ratios do not apply, however, to chametz on Pesach. If chametz became mixed with non-chametz on Pesach, the mixture is prohibited on Pesach even if the ratio of the permitted non‑chametz to the forbidden chametz is 1,000 to 1. This applies both to foods that blend together, lach belach, such as chametz flour and Pesach flour and foods that do not blend together, yavesh beyanesh, such as a piece of kasher lePesach matzah with a piece of non-kasher lePesach matzah.
According to Rashi, the reason for this stringency on Pesach as opposed to the rest of the year is twofold. First, the punishment for eating chametz on Pesach is karet, premature death at the hand of God. Second, since the prohibition of chametz exists for only seven days a year, one might come to forget about it – lo dedilay minay. The combination of the severity of the punishment and the ease with which the prohibition may be forgotten require that the smallest amount of chametz – chametz bemashehu – be prohibited.
According to the Rambam, the reason for the stringency on Pesach is that the chametz prohibition is a temporary prohibition – davar she’yesh lo matirin – because it lasts for only seven days. So why eat even the minutest amount of chametz on Pesach when one can wait until after Pesach and eat it without any concern? A temporary prohibition cannot be nullified, irrespective of how high the ratio of the permitted food is to the forbidden food. A practical difference between Rashi’s explanation and the Rambam’s explanation is the case of chametz nukshasoleh – spoiled or decomposed chametz. Although prohibited on Pesach, chametz nuksheh does not incur the punishment of karet. According to Rashi therefore, it could be batel beshishim, but according to Rambam it could not.
Certain combinations of chametz and non-chametz mixed together before Pesach, however, could become batel beshishim. For example, according to most opinions, beer mixed with wine before Pesach or Pesach flour mixed with chametz flour before Pesach, which are both cases of mixtures that blend together, lach belach, can be batel beshishim on Pesach. However, solids, which do not blend together, cannot be batel beshishim on Pesach even if they were mixed before Pesach. The reason is that in the case of solids, which remain visibly identifiable on Pesach, the prohibition of chametz in the smallest amount, chametz bemashehu, is revived, chozer veniur, on Pesach. In the case of liquids or foods that blend together, the chametz part is neither visible nor identifiable in the mixture and, therefore, the prohibition of the smallest amount of chametz bemashehu is not revived on Pesach.
With these principles in mind, let us go back to the supermarket. The following foods may be purchased before Pesach without the kasher lePesach stamp. This is because the ratio of chametz to non-chametz found in them is likely to be less than 1:60. These foods are, among others, granulated sugar, non-iodized table salt, instant coffee, freeze dried or percolator drip coffee, tea or tea bags, cocoa, and milk.
The following items require no kasher lePesach stamp even if purchased on Pesach: club soda, seltzer, fresh concentrated frozen juices (such as orange or grapefruit juice) fresh vegetables, plastic tablecloths, aluminum foil, paper plates, plastic spoons and forks, freezer paper, toothpicks, etc.
The following items always require a kasher lePesach stamp: canned and processed juices, fruit drinks, frozen fruits and frozen vegetables, sugar substitutes, brown sugar, spices and condiments, ketchup, mayonnaise, mustard, instant tea, cheese, and rennet. This is because they either contain chametz in unacceptable concentrations or because they are processed with chametz machinery. Fresh vegetables and fruit should be washed because they may be sprayed with chametz substances such as oleic acid.