Abstract: The present disclosure includes compositions and methods for filtering oil, e.g., for removing free fatty acids (FFAs) from an oil used for cooking. In one example, the composition may comprise a filter aid that includes an alkali silicate, and a composite material comprising a silicate mineral at least partially coated with an inorganic silica or silicate. In another example, filter aid includes an alkali silicate, and a silicate mineral, wherein at least a portion of the alkali silicate is present as a coating on the silicate mineral, and wherein the ratio of said alkali silicate to silicate mineral in the filter aid ranges from about 1:4 to 4:1 by weight. In yet another example, the filter aid includes an alkali silicate, a silicate mineral, and an adsorbent. The method of filtering an oil may include combining the oil with the filter aid, optionally heating the mixture, and separating at least a portion of the filter aid from the oil to thereby remove at least a portion of the FFAs from the oil.