The improvement of dairy product quality is vital for the continued economic growth of the dairy industry. Poor quality is characterized by the development of off flavors, odors, and textures that negatively impact consumer experiences and reduce shelf life. This reduction in quality may be influenced by a variety of microbial and physiochemical processes that occur within the raw milk and finished products. It is important to understand the root cause of these processes and the methods by which they are introduced across the supply chain, from the bulk tank raw milk produced on dairy farms to the finished product packaged in processing facilities. To address this, two investigations were conducted. The first investigation aimed to identify on farm factors that affect the quality of bulk tank raw milk as determined through traditional and novel measures as well as provide evidence to support the selection of methods to assess quality in raw milk that may be indicative of finished product quality. Research on raw milk has traditionally focused on farm management practices that impact total bacteria count and somatic cell count, however there is more limited understanding on how sporeformers and sensory characteristics may be affected. To achieve this, 100 New York State dairy farms were sampled 6 times each, over the course of 15-months. Samples were evaluated for 24 quality parameters and results were analyzed in a variety of ways including correlation analysis between test results as well as the development of random forest models for evaluation of drivers of spore levels and sensory characteristics. Interestingly, our results suggest that i) udder health and hygiene is impactful on levels of sporeformers in bulk tank raw milk, ii) factors affecting the fatty acid profile impact sensory characteristics, and iii) monitoring total bacteria count, mesophilic spore count, and fatty acid profile may provide farmers with data to effectively assess overall milk quality. In the processing facility despite process controls put in place to improve quality, the product may be impacted by the recontamination of product following pasteurization with Gram-negative bacteria. Thus, it is critical to understand routes of contamination within processing facilities. The second investigation aimed to assess the role of filling equipment in post pasteurization contamination (PPC) and evaluate the effectiveness of preventive maintenance (PM) on reducing the rates of contamination. This study involved three total visits to two fluid milk processing facilities to collect wearable components replaced during routine PM and evaluate the impact of PM on milk quality. Components were enriched in brain heart infusion broth and plated on standard methods agar (SMA) and crystal violet tetrazolium agar (CVTA) to evaluate for presence of Gram-negative bacteria. Skim milk cartons were collected prior to and following PM and stored at 6C for 14 days to simulate mild temperature abuse before being plated on SMA and CVTA to evaluate for rates of PPC. The results of the second study suggest that i) filing equipment is a source of PPC but routine PMs do not prevent finished product contamination ii) CVTA may serve as a useful tool to evaluate the effectiveness of cleaning and sanitation procedures, and iii) knowledge drift amongst maintenance employees may lead to elevated rates of PPC. Overall, the outcomes of these two studies will help the dairy industry to identify areas of production to improve that will have the greatest impact on overall dairy product quality.