Produce Assumed to Be Infested

27. Majority. If produce is assumed to be infested, i.e., the majority of the produce is infested (ערוה''ש סי' פ''ד סע''ב ), the chiyuv to check it is d’oraisa (רשב''א שם ). If one did not check it, it may not be eaten even b’dieved. Likewise, if it was cooked already and cannot be checked anymore, its ossur even b’dieved.

28. Some say even if infestation occurs less than 50% of the time, if it is near the majority of the time, it is considered “assumed to be infested” and the chiyuv to check is d’oraisa (מקור חיים או''ח ריש סי' תל''א ).