NOVELTY - Producing (m1) a blown and stripped biorenewable oil, comprises: (a) heating a biorenewable oil to at least 90 degrees C; (b) exposing an oxygen containing stream to the heated oil to produce a blown oil having a viscosity of at least 40 cSt at 40 degrees C; (c) adding a base metal catalyst to the blown oil; and (d) stripping the blown oil until the stripped oil has an acid value of 1-20 mg potassium hydroxide/g, where the stripped oil has a flash point of at least 220 degrees C.    USE - The method is useful for producing a blown and stripped biorenewable oil (claimed).    ADVANTAGE - The method produces a blown, stripped biorenewable oil: having a high viscosity and a low acid value, which will result in high flash point and superior asphalt performance (e.g. reducing short term age hardening and volatile mass loss); and that is not only a viable substitutes for mineral oil, but have shows to extend the useful temperature interval of asphalts to a greater degree than other performance modifiers, providing substantial value to asphalt manufacturers.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) producing (m2) a blown and stripped biorenewable oil, comprising (a1) heating a composition comprising biorenewable oil and a first catalyst to at least 90 degrees C, (b1) exposing an oxygen containing stream to the heated composition to produce a blown oil having a viscosity of at least 40 cSt at 40 degrees C, (c1) adding a second catalyst to the blown oil and (d1) stripping the blown oil to produce a stripped oil having an acid value of 1-20 potassium hydroxide/g, where the first and the second catalysts are different;    (2) producing (m3) a blown and stripped biorenewable oil (m3) comprising (a2) heating a biorenewable oil to at least 90 degrees C, (b2) exposing an oxygen containing stream to the heated oil to produce a blown oil having hydroxy value of 10-70 and (e2) stripping the blown oil to produce a stripped oil having an acid value of 1-20 mg potassium hydroxide/g; and    (3) producing (m4) a blown biorenewable oil, comprising (a3) heating the oil to at least 90 degrees C, (b3) exposing an oxygen containing stream to the heated oil to produce a blown oil having a viscosity of 40-50 cSt at 40 degrees C, where the blown oil has a flash point of at least 220 degrees C.