Applying the simulated gastrointestinal digestion protocol allows for estimating the bioaccessibility of ochratoxin A (OTA) in grape juice and red wine. The methodology reproduces the oral, gastric, and intestinal phases using standardized simulated fluids, controlling pH, time, and enzymatic activity. Adaptations are made for liquid matrices with a high concentration of phenolic compounds and the presence of ethanol. This methodology enables detailed analysis of the bioaccessible OTA fraction, supporting food safety assessments and contributing to regulatory and technological strategies to mitigate OTA exposure.