Acid-base titration laboratories are perennially offered to general chemistry students in preparation for summative assessments of their hands-on and quantitative skills in the field. Here, we present a guided inquiry-based activity focused on total titratable acidity (TTA) as alternative to standard "cookbook" titration laboratory work. This activity is cost-neutral compared with traditional acid-base or buffer titration laboratory activities and introduces students to the iteration and revision aspects of inquiry and independent research. By incorporating TTA as the main quantity to be measured by students, the laboratory activity also introduces an authentic, job-relevant methodology in their first year of undergraduate study.