Nullification

The Torah introduces a halachic mechanism in which the minority is nullified in the majority called Bitul.

Bitul BeRov

1. If non-Kosher solid food is mixed up in a simple majority (51%) of Kosher food, and the non-Kosher food is similar in taste to the non-Kosher piece, is unrecognizable in the mixture, and the mixture is not hot or cooked together, then mixture as a whole is permissible.
2. When a mixture is permissible because of nullification one person may eat the entire mixture at different intervals and not all at once. It is preferable for one Jew not to eat the entire mixture but rather leave one piece and let another person eat it. It is even more meritorious to be strict to discard one piece or to give it to a non-Jew.
3. Certain prohibited foods require a higher ratio for nullification. For example, Trumah, Challah, and Bikkurim require a 1 (forbidden) to 100 (permitted) ratio and Orlah and Kelayim require a 1 to 200 ratio.

Bitul BeShishim

1. If the mixture comprised of either 1)foods of dissimilar taste, 2)liquids, or 3)solids that were hot or cooked together, the nullification required is 1 to 60 called Bitul BeSheshim.
2. If solid foods which were cold and of similar taste are subsequently cooked together the nullification required is Bitul BeShishim. According to Ashkenazim in cases of loss it’s permissible to use the nullification of Bitul BeRov if one knew at first that there was a mixture of non-Kosher and Kosher prior to the mixture being cooked.

Foods for which nullification doesn’t work

1. If the prohibited food will be permitted after a certain time, nullification doesn’t work unless it is mixed with a different type of food (different in name) in which case Bitul BeShishim is effective. Therefore Chadash grain can not be nullified.
2. Tevel (produce of Israel wfrom which Trumot and Masserot have not been removed), wine poured to Avoda Zara, and produce of Isreal from the Shemitta (Sabbatical year) can’t be nullified unless it is mixed with a different type of food (different in name) in which case Bitul BeShishim is effective.
3. Chametz on Pesach and foods use to serve Avoda Zara can not be nullified in any amount.
4. A complete creature or limb, a piece of meat which is suitable to serve guests, items which are always sold by unit (eggs which are sold by the dozen), and a prominent item (that Chazal specified) can not be nullified. According to Ashkenazim a piece of meat which would be suitable to serve guests after being cooked is not able to be nullified and according to Sephardim only a piece of meat which is suitable to serve guests as of now (meaning, that it is cooked) is not able to be nullified.

Intentional Bitul

1. It's forbidden to intentionally mix forbidden food into permissible food so that it should become nullified.
2. If a forbidden ingredient falls into kosher food one may not increase the ratio of kosher food to non-kosher in order to nullify the non-kosher.
3. There is a prohibition of benefit to the one who intentionally causes a nullification unless there is an express permit (as certain cases do). Others however may benefit from the mixture if it wasn't done specifically for their sake.