Baba Metzia 3:7-8

Baba Metzia 3:7

When one person watches another’s produce, he may deduct certain amounts for loss (such as from mice). For wheat and rice, the amount is nine half-kav per kor (that’s 2.5% of the total); for barley and millet, nine kav per kor (5% of the total); for spelt and linseed, three seah per kor (10% of the total). The custodian deducts this from each kor of grain and for every year that he watches it. Rabbi Yochanan ben Nuri asked why mice should care about how much grain the custodian is watching – they’re going to eat whatever they’re going to eat no matter how much he’s holding! Therefore, the guardian only deducts these losses from one kor of grain. Rabbi Yehuda says that if the custodian is holding a large volume of grain (10 kor or more), he doesn’t deduct anything because it actually increases in volume (it expands from moisture, more than compensating for what mice may eat).

Baba Metzia 3:8

The guardian of wine may deduct one-sixth for losses (absorption, sediment, etc.); Rabbi Yehuda says one-fifth. The watchman of oil may deduct three log (a measure of volume) for every 100 – a log and a half for sediment and a log and a half for absorption. If the oil has been filtered, he may not deduct for sediment (because there isn’t any). If the jugs are old, he may not deduct for absorption (because they’re already saturated and no longer absorb). Rabbi Yehuda says that if one person sells another filtered oil throughout the year, then the buyer must accept the seller deducting a log and a half per hundred for sediment.