According to the National Science Foundation (NSF), 78% of consumers report throwing out milk and other dairy products once the date on the label has passed (1).

Yet, the date on your milk doesn’t necessarily indicate that it’s no longer safe to drink. In fact, most milks can be consumed several days past the date printed on the label.

This article explains what the date on your milk means and how long milk is safe to drink after the printed date.

食物占混乱日期标签nearly 20% of consumer food waste in the United States ( 2 ).

This is largely because the Food and Drug Administration (FDA) doesn’t regulate the date labeling of food products, with the exception of infant formula ( 2 ,3).

Some states regulate if and how expiration dates onmilkshould be labeled, but these regulations differ between states (4).

This means you may see several types of dates on your milk carton — none of which indicate food safety (3):

  • Best if used by．This date indicates when to consume the milk by for the best quality.
  • Sell by．This date can help stores with inventory management, as it tells when to sell the milk by to ensure the best quality.
  • Use by．This date is the last day you can expect the product to be at peak quality.

Therefore, the printed date can give you an idea of when the quality will start to decline. However, it doesn’t mean that your milk will expire and be unsafe to drink immediately after that date.

Summary

The FDA doesn’t require manufacturers to print an expiration date on milk. Instead, you’ll often see a “use by” or “sell by” date, which is a recommendation regarding quality, not necessarily safety.

In the United States, most milk purchased from the grocery store has been pasteurized (5).

Pasteurization is a process that involves heating milk to destroy potentially harmful bacteria, includingE. coli,Listeria, andSalmonella．By doing this, the shelf life of milk is extended by 2–3 weeks ( 6 ,7).

However, pasteurization can’t kill all the bacteria, and those that remain will continue to grow, eventually causing the milk to spoil ( 8 ).

One study found that the temperature in your refrigerator greatly affects how long your milk stays good past the listed date. Simply by reducing the refrigerator temperature from 43°F (6°C) to 39°F (4°C), the shelf life was lengthened by 9 days ( 8 ).

While there are no set recommendations, most research suggests that as long as it’s been stored properly, unopened milk generally stays good for 5–7 days past its listed date, while opened milk lasts at least 2–3 days past this date (3, 8 ,9).

Unless milk is shelf-stable, it should never be left out at room temperature for more than 2 hours, as this increases your risk of foodborne illness (3).

In contrast,raw milkhas not been pasteurized and has a shorter shelf life. Drinking this type may also increase your risk of foodborne illness ( 10 , 11 ).

Finally, there’s unrefrigerated milk, also called shelf-stable or aseptic milk, which is produced using ultra-heat treatment (UHT). UHT is similar to pasteurization but uses higher heat, making unopened milk products safe to store at room temperature ( 12 ).

Unopened, UHT milk can generally last 2–4 weeks past the printed date if stored in a cool, dry pantry, and up to 1–2 months in the fridge. However, once opened, UHT milk should be stored in the fridge and consumed within 7–10 days (9).

Of course, regardless of the listed date, it’s always important to examine your milk first for any signs of spoilage, such as a sour smell or change in texture.

Ways to make your milk last longer

Milk may be good for several days after the sell-by or best-by date. However, you can still end up withspoiled milkif you don’t store and handle it properly.

Here are a few tips on how to keep your milk from spoiling quickly (13):

  • unless it’s shelf-stable, place milk in the fridge as soon as possible after purchase
  • keep your refrigerator temperature between 38°F (3°C) and 40°F (4°C)
  • store milk on an interior shelf in your fridge rather than on a shelf in the door
  • after use, always tightly seal and quickly return the carton to the fridge

While milk can be frozen for up to 3 months, freezing and subsequent thawing can result in undesirable changes in texture and color. That said, it will be safe to drink (14).

SUMMARY

Even after opening, most milk is safe to drink for several days past the use-by or sell-by date. Proper storage and handling may help it stay fresh and safe for longer. However, it’s always important to check for signs of spoilage before drinking.

As the date on your milk doesn’t always indicate safety, the best way to tell if milk is okay to drink is by using your senses.

One of the first signs that your milk has expired is a change in smell.

Spoiled milk has a distinct sour odor, which is due tolactic acidproduced by bacteria. Other signs of spoilage include a slightly yellow color and lumpy texture (15).

Summary

Signs that your milk has spoiled and may not be safe to drink include a sour smell and taste, change in color, and lumpy texture.

Drinking a sip or two of spoiled milk is unlikely to cause any serious side effects.

However, consuming moderate or large amounts can causefood poisoningand result in symptoms like nausea, vomiting, stomach pain, and diarrhea ( 16 ).

If symptoms persist or worsen, or if you begin experiencing signs of dehydration, it’s important to make an appointment with your healthcare provider ( 16 ).

Summary

While a sip of spoiled milk is unlikely to cause any harm, drinking moderate to large amounts could cause food poisoning and result in symptoms such as vomiting, stomach pain, and diarrhea.

Due to confusion over labeling on milk cartons, many consumers throw away milk before it goes bad.

While it’s always important to inspect your milk before drinking it, most milks are safe to drink several days after the printed date on the label. That said, the flavor may start to decline.

To avoid food waste, older milk can be put to use in pancakes, baked goods, or soups.