Abstract SIMANCA S, Mónica et al. Characterization and study of spontaneous fermentation of fermented milk product (suero costeño) produced in Monteria. Rev. MVZ Cordoba [online]. 2010, vol. 15, n. 1, pp. 1944-1953. ISSN 0122-0268. Objective. Describe the fermentation process of fermented milk product (suero costeño) produced in Monteria. Materials and methods. The fermented homemade product was characterized by physic-chemical and bromatological means. The homemade product was evaluated during 24 hours for