- One of the most important issues in the area of Kashrus is the nullification of forbidden foods. If non-kosher food becomes mixed with a greater amount of kosher food, the non-kosher food becomes nullified (batel). There are two ways to achieve this nullification.
I. Bitul b'Rov = Nullification in a Majority
A. If similar tasting, cold, dry foods are mixed together, the non-kosher food becomes nullified if there is a simple majority of kosher food in the mixture, i.e. there is more kosher food than non-kosher food in the mixture.
B. The majority halachic opinion is that of the Rashba [Rabbi Shlomo Ibn Aderes, the Rav of Barcelona (1235-1310)]. The Rashba, in Toras HaBayis 4:1, holds that Bitul b'Rov is based on the idea that if any part of the mixture is removed to eat therefrom, we may assume that piece is from the majority (kosher) food. The same person may even eat the last piece, although the entire mixture should not be eaten all at once (see also Yoreh Deah 109:1). Some rule that the last piece should be discarded.
C. Certain foods need more than a simple majority to achieve bitul. These foods are Terumah (the Kohen's share of most produce), Challah (the Kohen's share from dough), and Bikurim (the Kohen's share of the first ripened seven species fruit). II. Bitul b'Shishim = Nullification in a Ratio of Sixty
A. This type of nullification is applied to mixtures where the taste of the non-kosher food is noticeable. Since we have the principle of Taam k'Ikar, "the taste is the essence", food assumes the characteristics of the taste. If non-kosher food is added to the mixture and the taste is noticeable, bitul b'rov is not possible. The food must be nullified only in a ratio of 60/1, kosher to non-kosher food.
B. According to the Torah, Bitul b'Shishim is required in these cases:
1). Foods do not have the same taste (min b'sheaino mino)
2). The foods are mixed or cooked together
C. The Rabbinic prohibition extended this idea requiring Bitul b'Shishim in these cases:
1). Similar tasting foods that are mixed or cooked together
2). Similar tasting liquids mixed together
3). Different tasting foods, even if not cooked or mixed together
Different tasting solids
Similar tasting, cooked or mixed together solids
Similar tasting, uncooked, and non-mixed solids (unless subsequently cooked, then bitul b'shishim)