NOVELTY - Preparing fatty acid esters from organic matter involves obtaining organic matter; treating organic matter to increase its surface area to volume ratio; contacting organic matter in reaction mixture with basic solution to provide base-treated reaction mixture; removing, or sequestering or separating undigested solid organic matter or non-fat containing matter from base-treated mixture; and esterifying monomeric fatty acids of base-treated mixture and treating in presence of organic alcohol to provide for esterification mixture, where esterified fatty acids are provided.    USE - For preparing fatty acid esters, and also useful in production of biodiesel from water or fatty acid FFA, or FFAA-rich feedstocks.    ADVANTAGE - The method has cost-effective, water tolerance and economical effective. The method saving time and provide non costly sample preparation.    DETAILED DESCRIPTION - Preparing fatty acid esters from organic matter involves obtaining organic matter containing fat substituent; treating organic matter to increase its surface area to volume ratio; contacting organic matter in reaction mixture with basic solution under conditions to provide for hydrolytic release of monomeric fatty acids from fat substituent to provide base-treated reaction mixture; removing, or sequestering or separating undigested solid organic matter or non-fat containing matter from the base-treated mixture; and esterifying monomeric fatty acids of base-treated mixture by acidification of mixture and treating in presence of organic alcohol in greater than or equal to 5 (preferably 30) vol./vol.% , to provide for esterification mixture, where esterified fatty acids are provided. INDEPENDENT CLAIMS are included for following    (1) fat analysis of organic matter involving, obtaining sample of organic matter containing fat substituent; contacting the organic matter in reaction mixture with a basic solution to provide a base-treated reaction mixture; esterifying monomeric fatty acids of mixture by acidification of reaction mixture and treating in presence of organic alcohol to provide for esterification reaction mixture; and performing qualitative or quantitative analysis on fatty acid esters; and    (2) a kit for fat analysis of organic matter, comprising in at least one vials or reaction vials, a base to facilitate hydrolytic release of monomeric fatty acids; and acid to facilitate esterification of monomeric fatty acids to provide fatty acid esters.