(AP) -- Phil DeVore pulls a folded piece of aluminum from a murky pond. The aluminum looks like a piece of siding that's blown off a building, but DeVore knows it's much more valuable than that. He slips a rubber band off the aluminum and unfolds it. He likes what he sees -- 50 or 60 glistening black leeches. They're your common ribbon leeches, Nephelopsis obscura to aquatic biologists.
Store the oil to be reused in cooking or deep frying for no longer than three months and avoid re-using the oil for deep frying more than once or twice, as the smoke point of used oil is reduced after multiple uses. Avoid pouring your used deep fryer oil down the drain or tossing it in the trash.
Shelf life of sesame oil. It has been studied and stated that the storage duration of sesame seed oil is six months. It is hard to tell whether the oil became rancid by tasting it only, as the taste does not differ much. However, Ehow has some tips on finding out whether the oil went rancid, like heating it in order to determine the rancidity through scent.