The ice produced is utilized for refrigeration purposes. We are apt to think that the piece of ice in the home refrigerator is doing the work of food preservation, but behind this lies a long refrigerated channel through which foods travel from producer to consumer. For example, each refrigerator car holds from three to five tons of ice. With about 150,000 such cars, millions of tons of ice are used annually to protect our foods during transit. Additionally, hundreds of thousands of butcher boxes rely on ice as a refrigerant. The importance of milk preservation through ice is highlighted, noting that milk is never unaccompanied by its guardian and caretaker — ice. More than 6,000 factories supply America with over 42 million tons of ice each year, alongside natural ice harvesters providing about 15 million tons annually. Cities like New York use up to 3.75 million tons yearly, with precautionary measures ensuring a steady supply even during peak demand.
<Callout type="important" title="Critical for Food Safety">Ice is essential in maintaining the purity and safety of milk from farm to consumer.</Callout>
Properties of ice are discussed, including its unique expansion upon freezing and how agitation affects crystal formation. The United States Department of Agriculture provides guidelines on the quantity of ice required for dairy farms based on location and handling methods. Cost data for harvesting ice is also presented, with an average cost of about $1.50 per ton near the source.
<Callout type="tip" title="Efficient Ice Storage">Using cooling tanks can significantly reduce the amount of ice needed to cool cream and maintain it at a low temperature.</Callout>
The refrigeration required for making ice is calculated, showing that 194 B.t.u. are necessary per pound of ice when starting with water at 75°F.
<Callout type="risk" title="Potential Losses">Allowing approximately 20% extra for losses during the freezing process ensures a reliable supply.</Callout>
The chapter concludes by detailing standard sizes of ice cans and methods for cutting ice into blocks suitable for household refrigerators, emphasizing the importance of customer satisfaction through accurate weight measurements.
Key Takeaways
- Ice is crucial in maintaining food safety during transportation and storage.
- The ice industry plays a significant role in ensuring the availability of ice year-round.
- Understanding the properties of ice can improve its efficiency in refrigeration.
Practical Tips
- Use cooling tanks to reduce ice requirements for dairy farms.
- Ensure accurate weight measurements when cutting ice blocks for household use.
Warnings & Risks
- Failure to account for losses during ice production can lead to supply shortages.
- Improper handling of ice can compromise food safety and purity.
Modern Application
While modern refrigeration has largely replaced the need for ice in daily life, understanding historical methods provides valuable insights into preserving perishables without electricity. This knowledge is still relevant today for emergency situations or off-grid living scenarios.
Frequently Asked Questions
Q: How much ice does a dairy farm require per cow?
In the Northern States, half a ton of ice per cow is sufficient to cool cream and maintain it at a low temperature for delivery two or three times a week.
Q: What are the costs associated with harvesting ice?
The average cost of cutting ice is about 27 cents a ton, while the total cost including packing and hauling can be around $1.50 per ton near the source.
Q: Why is accurate weight measurement important when cutting ice blocks for household use?
Accurate weight measurements ensure customer satisfaction and prevent disputes over quantity, making it a crucial aspect of efficient ice delivery.