The chapter examines the influence of experimental design on the estimation of antimicrobial efficacy in food systems. It highlights the complexity of food matrices, which affect microbial survival and response to antimicrobial treatments. Key factors, such as water activity, pH, nutrient composition, and temperature, play crucial roles in shaping the effectiveness of antimicrobial agents. The chapter emphasizes the importance of designing experiments that accurately reflect real-world food environments, as well as considering intrinsic and extrinsic elements that influence microbial growth. The authors provide recommendations for developing in vitro experiments, addressing factors such as inoculum selection, microbial interactions, and atmospheric conditions. Additionally, various microbiological methods, including culture-based and molecular techniques, are discussed for quantifying microbial alterations. The chapter underscores the need for tailored experimental designs that account for the specific characteristics of food systems to improve antimicrobial efficacy assessments.