Abstract: An article for testing liquid for free fatty acid comprises a substantially nonreactive, neutral and non-buffering, porous, absorbant support material having at least one portion thereof which contains a composition comprising an effective amount of acid-base indicator capable of changing color, when the predetermined amount of base has reacted with the known amount of free fatty acid, in a pH range on the order of 6-10, a predetermined amount of base compound reactive with free fatty acid and being present in an amount equivalent to a known concentration of free fatty acid, and about 30-99.5 parts by weight of non-volatile material of a substantially colorless, substantially neutral, humectant polyalkylene glycol organic solvent which is substantially non-volatile under ambient conditions. An organic liquid to be tested is contacted with the article and any color change in the article after the passage of sufficient time is observed.