The objective of this research was to develop a fermented fresh cheese milkwhey beverage inoculated with Lactobacillus casei, to which the viability of microorganism was evaluated using selective cultivation means under anaerobic conditions and then it was verified its biliary resistance to gastric acids and salts, simulating this way, the conditions of gastrointestinal tract of humans. To verify the survival during the period of storage (21 days), the stump was characterized morphological and bio-chemically. Additionally the test of acceptability was carried out evaluating beverage with 80 judges. Physical-chemical, microbiological and sensorial analysis were made to raw material and to elaborated product, according to effective norms in Colombia. The beverage was flavored with pulp of maracuya (Passiflora edulis). Counts of viability to pH 2.0 were obtained, in MRS agar of 5,38·10