A Novel Milk Pail for Chilling Milk from the Farmer’s Doorsteps

Milk chilling at the farmer’s doorstep, particularly within smallholder and unorganized dairy systems, remains an unmet need in developing and underdeveloped regions. Conventional chilling solutions such as bulk milk chillers are designed for medium- to large-scale dairy enterprises and are not viable for decentralized milk production systems. Consequently, small and marginal farmers typically transport fresh raw milk to centralized village collection centers (often operated by dairy cooperative societies), where chilling commences only after pooling substantial quantities of milk (≥500 L). During this lag period, milk is usually transported under ambient conditions in cans or buckets to processing plants. In tropical environments, where ambient temperatures frequently exceed 40 °C, such practices lead to rapid microbial proliferation and biochemical deterioration of milk quality. These challenges are particularly pronounced in rural and remote areas, where smallholder farmers, owning two to three milch animals and producing 0.5–10 L of milk per day, contribute nearly 70–80% of total milk production in countries like India. To address this persistent bottleneck in the rural dairy cold chain, an energy-efficient, rechargeable thermal storage device, engineered in the form of a common milk pail, was conceptualized and developed at the ICAR–National Dairy Research Institute (NDRI), Bengaluru. The innovative system employs nanostructured phase change materials (n-PCMs) for on-site milk chilling and temporary storage, enabling immediate temperature reduction at the point of milk production without reliance on external power sources at the time of cooling. The present chapter details the conceptual framework, design principles, fabrication methodology, and on-farm performance evaluation of this novel milk chilling solution, aimed at empowering small and marginal dairy farmers while strengthening the grassroots milk value chain.