The food industry uses multiple antimicrobial agents to control and eliminate spoilage and pathogenic bacteria throughout the food chain. However, the selective pressure placed by these compounds can lead to the development of resistances that spread from farm to fork. This resistance emerges through horizontal gene transfer (HGT) or genetic adaptation, leading to increased tolerance and/or resistance to antimicrobial agents, such as antibiotics, biocides, and essential oils. The increase in tolerance and/or resistance could compromise the efficacy of the antimicrobial agents and affect food safety. To phenotypically characterize study strains and detect genetically resistant variants (RVs), this chapter provides detailed protocols for determining the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), growth kinetics, and survival curves against antimicrobial compounds. These methods enable comparison between parental strain and study strains, allowing for precise assessment of growth fitness, direct- and cross-tolerance and/or -resistance levels across different agents and treatments.