Numerous studies indicate that if milk is stored correctly, unopened cartons can typically remain fresh for 5 to 7 days beyond their expiration date, while opened milk can still be safe for at least 2 to 3 days after this date. However, a survey conducted by the National Science Foundation (NSF) reveals that a significant 78% of consumers tend to discard milk and other dairy products once the date on the label has elapsed. It’s essential to understand that this date doesn't necessarily mean that the milk is unsafe to consume. In reality, many types of milk can be enjoyed several days beyond the indicated date on their packaging.

This article delves into the significance of the date on your milk carton and provides insights into how long it remains safe for consumption after this printed date.

Understanding the Date Labels on Your Milk

The confusion surrounding date labeling on food items contributes to an astonishing 20% of consumer food waste globally. This issue is especially pronounced in countries like the United States, where regulations regarding food date labels are inconsistently enforced.

While the Food and Drug Administration (FDA) has stringent guidelines for infant formula, it does not standardize date labeling for other food products, including milk. In numerous regions, including parts of Australia and Canada, local authorities may impose their own regulations on how expiration dates are labeled on dairy products, resulting in significant variability across different jurisdictions.

Consequently, the milk carton in your fridge may present several types of dates, none of which serve as definitive indicators of food safety:

  • Best if used by: This date suggests when the milk is expected to be consumed for optimal quality.
  • Sell by: This date assists retailers with inventory control, indicating when the milk should be sold to maintain its best quality.
  • Use by: This date marks the final day when the milk can be expected to be at its peak quality.

While these dates may provide insight into when the quality of the milk will begin to decline, they do not imply that the milk will suddenly become unsafe for consumption after the specified date. The FDA does not mandate that manufacturers include an expiration date on milk; instead, consumers typically encounter “use by” or “sell by” dates, which relate to quality rather than safety.

How long is milk safe to consume after its expiration date?

In many countries, including India, Australia, Japan, and Canada, most milk obtained from retail stores undergoes a process known as pasteurization. This process involves heating the milk to eliminate potentially dangerous bacteria such as E. coli, Listeria, and Salmonella, subsequently extending the milk's shelf life by an additional 2 to 3 weeks. Nevertheless, while pasteurization significantly reduces harmful microorganisms, it does not eradicate all bacteria; those that remain can multiply, leading to spoilage over time.

A study indicated that the temperature at which you store milk in your refrigerator plays a crucial role in its longevity beyond the printed expiration date. By lowering the refrigerator temperature from 43°F (6°C) to 39°F (4°C), researchers found that the shelf life of milk could be extended by 9 days.

Although definitive guidelines are lacking, most studies suggest that unopened milk, when stored correctly, can remain good for approximately 5 to 7 days post its expiration date, while opened milk typically lasts at least 2 to 3 days beyond this time frame. Unless milk is shelf-stable, it should never be left out at room temperature for longer than 2 hours, as this significantly increases the risk of foodborne illnesses.

Conversely, raw milk, which has not undergone pasteurization, possesses a shorter shelf life and may elevate your risk of foodborne ailments. Additionally, there is unrefrigerated milk commonly referred to as shelf-stable or aseptic milk, produced through ultra-heat treatment (UHT). This method is akin to pasteurization but utilizes higher temperatures, allowing unopened milk products to be stored safely at room temperature.

Unopened UHT milk can generally last for 2 to 4 weeks past its printed date when stored in a cool, dry pantry, and up to 1 to 2 months when refrigerated. However, once opened, UHT milk should be kept in the fridge and consumed within 7 to 10 days. Regardless of the indicated date, it is always prudent to inspect your milk for any signs of spoilage, such as a sour odor or alterations in texture.

Tips for prolonging the freshness of your milk

Milk can remain suitable for consumption several days beyond the sell-by or best-by date. However, mishandling or improper storage can result in spoiled milk.

Here are some practical strategies to help your milk last longer:

  • Unless it’s shelf-stable, refrigerate milk immediately after purchase.
  • Maintain your refrigerator temperature between 38°F (3°C) and 40°F (4°C).
  • Store milk on an inner shelf of your fridge rather than in the door to avoid temperature fluctuations.
  • Always seal the carton tightly after use and promptly return it to the fridge.

Although milk can be frozen for up to 3 months, the freezing and thawing process might lead to undesirable changes in texture and color. Nonetheless, it remains safe for consumption. Even after being opened, most milk is safe for drinking for several days beyond the use-by or sell-by date. Proper storage and handling can help maintain its freshness and safety for a longer period. Nevertheless, it's essential to check for any signs of spoilage before consumption.

How to Determine if Your Milk is Still Safe for Consumption

Since the expiration date on milk doesn't always guarantee its safety, the most reliable method to assess its drinkability is through your sensory perception. One of the initial indicators that your milk has gone bad is a noticeable alteration in its aroma. Soured milk typically emits a strong, unpleasant odor, primarily caused by lactic acid produced by bacterial growth. Additional signs of spoilage encompass a yellowish tint and a curdled texture. Indicators that your milk has deteriorated and may no longer be safe to consume include a sour scent and flavor, discoloration, and a clumpy consistency.

Possible Side Effects of Consuming Expired Milk

Taking a small sip or two of spoiled milk is generally not expected to lead to any significant adverse effects. However, if you consume moderate to large quantities, you may experience food poisoning, which can manifest as symptoms including nausea, vomiting, abdominal pain, and diarrhea.

Should these symptoms continue or intensify, or if you start to notice signs of dehydration, it is crucial to consult with your healthcare provider promptly. While a tiny taste of expired milk is unlikely to be harmful, larger amounts can indeed lead to food poisoning, characterized by symptoms like vomiting, stomach discomfort, and diarrhea.

The Bottom Line

Confusion surrounding the labeling on milk cartons often leads many consumers to discard milk prematurely, well before it reaches its expiration. It's crucial to always examine your milk prior to consumption; however, most varieties are still safe to enjoy several days beyond the date printed on the carton. That being said, the flavor profile may begin to diminish over time.
To minimize food waste, consider utilizing older milk in delicious recipes such as pancakes, baked goods, or soups.