This research evaluates the effectiveness of a concentrated, buffered vinegar product (CBV) and a simple buffered vinegar product (BV) for controlling Clostridium perfringens outgrowth during extended cooling times of ready-to-eat roast turkey and roast beef respectively. Whole turkey breasts and beef inside rounds were injected with a typical brine, then ground and mixed with CBV (0.0, 2.01, 2.70 and 3.30% wt/wt) or BV (0.0, 1.75, 2.25, and 3.75% wt/wt) and a three-strain C. perfringens spore cocktail to a detectable level of ca. 2-3 log CFU/g. The meat was divided into 10g portions and vacuum packaged and stored frozen until tested. The meat was cooked in a programmable water bath to 71.6°C (160.8°F) in 5 hours. The meat was then cooled exponentially with the times between 48.9°C and 12.8°C (120°F and 55°F) lasting 6, 9, 12, 15, and 18 hours for the five different cooling treatments. The cooling continued until the temperature reached 4.4°C (40°F). C. perfringens counts were taken at 54.4°C (130°F) and 4.4°C (40°F). At a 2.01% concentration, CBV effectively limited C. perfringens growth to 1-log or less up to a 9-hour cooling treatment, while 2.70 and 3.30% concentrations were effective up to the 18 hour cooling treatment. BV had an inhibitory effect on C. perfringens outgrowth in roast beef, but did not limit growth to 1-log or less at any concentration tested for any of the cooling treatments.