Pulque is a traditional Mexican beverage produced through the fermentation of agave sap (aguamiel). Its primary sensory properties are attributed to the fermentative activity of Saccharomyces cerevisiae, Leuconostoc mesenteroides, and Zymomonas mobilis. However, the overproliferation of these microorganisms results in an extremely short shelf life, which hinders its commercialization. Tomatillo accrescent calyx extract (TACE) shows potential as a food preservative due to its high physalin content. Therefore, this study aimed to evaluate the effect of adding microencapsulated TACE on the shelf life and organoleptic properties of pulque. The extract demonstrated effective antimicrobial activity against L. mesenteroides, Z. mobilis, and S. cerevisiae, successfully delaying further fermentation. Additionally, the addition of TACE prevented an excessive increase in acidity, maintaining values suitable for consumption for up to 15 days, in accordance with regulatory standards, while the viscosity and alcohol content were not negatively affected. These findings suggest that TACE has significant potential for preserving both the microbiological and sensory quality of pulque.