What temperature must farm bulk tanks cool 25 percent of their volume to within two hours after milking?

The correct temperature that farm bulk tanks must cool 25 percent of their volume to within two hours after milking is 45 degrees F. This requirement is based on guidelines established to ensure the safety and quality of milk. Keeping milk at a lower temperature helps to inhibit the growth of bacteria, thereby maintaining the freshness and quality of the milk.

Maintaining the temperature at or below 45 degrees F is crucial because it falls in line with regulations that are designed to protect public health. A temperature of 45 degrees F is considered a threshold that balances the need for safe storage and the practicalities of cooling systems on a farm. Cooling milk rapidly after milking limits bacterial growth and preserves the quality necessary for processing and consumption.

In contrast, temperatures higher than 45 degrees F could increase the risk of spoilage. For instance, milk stored at 50 degrees F would allow for more bacterial growth, negatively impacting its quality. Similarly, while 35 degrees F and 40 degrees F are cooler than the maximum allowed temperature, they do not represent the proper threshold for the specified time frame and volume cooling requirement mandated by dairy industry standards. Thus, the chosen answer reflects the balance of safety, quality, and regulation within the outlined timeframe.