A method of making a sorbent from waste rubber and a method of sorbing oil using such sorbent. Approximately two pounds of modifier is added to 100 pounds of vulcanized rubber waste, the modifier comprising a mixture by weight of (i) a slightly water-soluble organic acid having a melting point of 70.degree. C. or higher representing 80%, (ii) quinine group bases representing 19% and (iii) 1% of an anti sliding ingredient such as colophony, running the mixture of rubber waste and modifier in a roll mill approximately six times to crush it and placing the crushed modified rubber particles in an extruder for 2-10 minutes at 120-150.degree. C. The sorbent can then be applied to oil to sorb six times its own weight in oil. The sorbent can be re-used two more times after extracting the oil. The sorbent is also effective at filtering oil from water.