If you live in an area with frequent major storms or power outages, a pantry full of canned goods and other durable foods can do a great deal for your peace of mind. They won't spoil when your power goes out, and don't require much care while they're in storage. Even milk becomes a sturdy, reliable pantry product when it's concentrated through evaporation and then canned. Evaporated milk usually has a one-year freshness date, but is good for much longer.
Ancient Idea, Modern Process
Milk's value as a food is matched only by its unfortunate tendency to spoil in as little as a few hours, if it's left out of the refrigerator. Beneficial bacteria can extend its life in the forms of yogurt, kefir or cheese, and many cultures -- especially in India -- boil the milk down to a thick paste to preserve it for longer. That idea was revived in the 19th century and combined with the new technology of canning, to provide a long-lasting form of milk for ocean voyagers and other travelers. Modern evaporated milk is boiled at low temperature in a partial vacuum, so its flavor -- though slightly "cooked" -- remains mild.
Freshness vs. Expiration
It's important to understand that evaporated milk doesn't really expire, as such. The date you'll see printed on many brands is simply a freshness date. That's the manufacturer's estimate of how long it will provide the best and freshest flavor, and it's usually conservative. The manufacturer has a vested interest in maintaining its reputation for quality, and also in selling more cans of milk. In truth, evaporated milk that's stored carefully should remain perfectly usable for two to four years, though it might darken and develop a stronger flavor over time.
The Importance of Storage
Like most other canned products, evaporated milk is undemanding in its storage requirements. The best places to store canned goods are cool and dry, with a temperature that fluctuates little over time. Ventilation is also important, to prevent any buildup of moisture that might cause the cans to rust. A dry, well-ventilated cellar or pantry works well. The seals on deeply rusted or deeply dented cans can sometimes fail, but a small amount of surface rust isn't necessarily an issue. If it wipes off, your milk should still be safe to use.
Once It's Open
If you have any doubt about the safety of a can of milk, open it. Spoiled evaporated milk is just as strong-smelling as spoiled fresh milk, so you'll have little difficulty detecting any problems. Assuming the milk is still usable, refrigerate it as soon as it's opened. Once the seal of the can is broken it's a perishable dairy product, best consumed within three to four days. Depending on the storage conditions the individual can has experienced, it can remain fresh-tasting and usable for longer.
- U.S. Department of Agriculture Food Safety and Inspection Service: Food Product Dating
- U.S. Department of Agriculture Food Safety and Inspection Service: Shelf Stable Food
- Eat By Date: How Long Does Evaporated Milk Last?
- On Food and Cooking: The Science and Lore of the Kitchen; Harold McGee
- Photo Credit Justin Sullivan/Getty Images News/Getty Images