Is 5 day old milk ok to drink?

November 27, 2025 •

4 min read

According to the Food Standards Agency, 'best before' dates refer to quality, not safety, meaning milk can often be consumed past this date. The real question of whether 5 day old milk is ok to drink depends on factors beyond the printed date, like storage conditions and visual and olfactory cues.

Quick Summary

The drinkability of 5-day-old milk is not solely determined by the date on the carton but by proper storage and sensory indicators of spoilage. Learning to use sight, smell, and texture checks is crucial for food safety and preventing illness from bad milk.

Key Points

Trust your senses over the date: The 'sell-by' or 'best before' date is a guideline; your eyes and nose are the best judge for milk safety.
Check for a sour smell: A pungent, sour odor is the most reliable sign that milk has spoiled due to bacterial growth.
Look for curdling or lumps: Visually inspect the milk for a slimy or chunky consistency, which indicates spoilage.
Store milk correctly: Keep milk in the coldest part of your fridge (typically the back) at or below 40°F (4°C) to maximize its shelf life.
Never consume truly spoiled milk: Drinking large amounts of bad milk can cause digestive issues like vomiting and diarrhea; when in doubt, throw it out.
Use slightly off milk for cooking: If milk is only slightly acidic and shows no signs of curdling, you can safely use it in baked goods like pancakes or biscuits.

Understanding the difference between 'best before' and 'use by' dates

Many people confuse the date printed on their milk carton with a strict expiration date. However, there is a critical distinction between different types of date labeling that affects how long you can safely consume the product.

'Best Before' Date: This date indicates when the product is at its peak quality in terms of flavor and texture. After this date, the milk may start to lose its fresh taste, but it is not necessarily unsafe to consume. For most milks, if properly stored, it can be consumed for several days past this date, provided it shows no signs of spoilage.
'Use By' Date: This date, on the other hand, is all about safety. It is typically found on foods that go off quickly, and you should not consume the product after this date, even if it looks and smells fine, as it could pose a health risk.

For most pasteurized milk sold in the US, the date is a 'sell by' date, which is simply a guideline for stores to manage inventory. This means the milk is often fine to drink for about a week past this date if it has been handled correctly.

How to safely check if 5 day old milk is ok to drink

Instead of relying solely on the date, you should use your senses to check for signs of spoilage. The following is a step-by-step guide to assess your milk's safety:

The Sniff Test: A fresh glass of milk has a mild, clean aroma. Spoiled milk, however, will have a distinct, pungent, sour smell. This is often the first and most reliable indicator that bacteria have taken over. If it smells off, it's best to discard it.
The Visual Test: Pour some of the milk into a clear glass. Fresh milk is a uniform, opaque white liquid. Look for any signs of discoloration, such as a yellowish tinge, or curdling. A lumpy or separated consistency is a clear sign that the milk is no longer safe to drink.
The Texture Test: While closely related to the visual check, the texture can also give you clues. If the milk is slimy or thicker than usual when you pour it, bacterial growth has likely occurred.
The Taste Test (as a last resort): Only if the milk passes all other sensory checks should you attempt a small sip. Fresh milk should taste as expected. If you detect any acidic or sour flavor, spit it out and throw the rest away.

Factors that influence milk's freshness

Several factors can affect how quickly your milk spoils, regardless of the date on the carton:

Storage Temperature: Milk should always be stored at or below 40°F (4°C). Keeping it on a door shelf where temperatures fluctuate can cause it to spoil faster than storing it in the colder back of the fridge.
Light Exposure: Some research suggests that light can cause flavor changes in milk through a process called oxidation. Storing milk in opaque containers or away from light sources can help preserve its taste.
Handling: Repeatedly leaving the milk out of the fridge or drinking directly from the carton can introduce bacteria, speeding up the spoilage process.

Comparison Table: Milk Types and Typical Longevity


Milk Type	Unopened Shelf Life Past Date	Opened Shelf Life Past Date	Additional Notes
Pasteurized Milk	5-7 days after the 'sell-by' date	4-7 days after opening, possibly past the 'sell-by' date	Standard milk, requires constant refrigeration.
Ultra-Pasteurized (UHT)	Up to 90 days unopened at room temperature	7-10 days once opened and refrigerated	Higher heat treatment extends shelf life significantly.
Raw Milk	Less than 7 days	Much shorter lifespan, handle with extreme caution	Not treated, carries higher risk of foodborne illness.
Non-Dairy Milk	Varies by brand and type, often longer	Varies by brand, typically 7-10 days	Check specific package for storage instructions.

What happens if you drink spoiled milk?

Ingesting spoiled milk can lead to foodborne illness due to the overgrowth of bacteria. While a small sip might not cause harm, consuming a moderate or large amount can result in uncomfortable digestive symptoms. These symptoms include nausea, vomiting, abdominal pain, and diarrhea. If you accidentally consume a larger quantity and feel unwell, it's best to stay hydrated and seek medical attention if symptoms persist.

How to use slightly spoiled milk

If your milk is only slightly acidic but has not curdled or molded, you can use it for cooking and baking. The heat from baking will kill any remaining bacteria, and the slight acidity can add flavor and moisture to certain recipes. This is a great way to reduce food waste.

Baking: Substitute slightly sour milk for buttermilk in recipes for pancakes, biscuits, and cornbread.
Marinades: Use slightly acidic milk to tenderize meat or fish.
Soups and Stews: Add a splash of sour milk to thicken and enrich creamy soups and stews.

Conclusion: The simple rules for 5 day old milk

The safety of 5 day old milk isn't determined by a single number but by a combination of proper storage and sensory cues. Always trust your senses: if the milk has a sour smell, an altered texture, or an off taste, it's best to throw it out to avoid foodborne illness. If it passes all sensory checks, it is likely safe to consume. By paying attention to these signs, you can prevent unnecessary food waste while keeping yourself and your family safe.

For more detailed information on food safety, consider visiting the official FoodSafety.gov website for guidance.

Frequently Asked Questions

If properly refrigerated, most opened pasteurized milk is good for about 4-7 days past the 'sell-by' date. However, you should always check for signs of spoilage before consuming.

Yes, if the milk has gone bad, you can get food poisoning from the overgrowth of bacteria. The risk depends on how spoiled the milk is and how much you consume.

The fastest way to check for spoilage is the sniff test. If the milk has a noticeably sour odor, it has gone bad and should be discarded immediately.

Yes, UHT milk is heated to a much higher temperature and has a significantly longer unopened shelf life, often up to 90 days. Once opened, however, it should be refrigerated and consumed within 7-10 days.

If the milk has a slightly sour smell but no other signs of spoilage, it is often fine to use for cooking or baking, where the heat will kill any bacteria. Do not drink it straight.

Yes, you can freeze milk to extend its life for several months. Thaw it in the refrigerator and stir well, as the texture may become grainy or separated.

No, according to the FDA, milk should not be left out at room temperature for more than two hours. If the temperature is above 90°F, it should be discarded after one hour.