The validation of elastographic methods benefits from the use of properly calibrated physical phantoms. In this work, the results of the characterization of gelatin phantoms using Crawling Wave Sonoelastography (CWS) are presented. Phantoms with different gelatin concentrations were prepared, and the elastic modulus was estimated using CWS at several frequencies between 80 and340 Hz and temperatures between 12 and 20 degrees Celsius. It was found that the average elastic modulus from a single phantom ranged between 50 and 140 KPa depending on the gelatin concentration, vibration frequency and temperature. The results suggest that reproducible results in terms of elastic behavior can be obtained when following the procedure for phantom manufacturing. Further, the estimated elastic moduli were consistent with the theory of viscoelastic materials, specifically in terms of the relationship of the Young’s modulus with the concentration of gelatin and the temperature of the phantom.