Can unopened almond milk be left out overnight?

Almond milk has become a popular plant-based milk alternative for many people. It is made from ground almonds and water, sometimes with added vitamins, minerals and flavors. Unlike regular dairy milk, almond milk does not contain lactose so it is suitable for people with lactose intolerance. However, there are some important food safety considerations when storing almond milk, especially if left unrefrigerated overnight.

Factors that Influence Food Safety

There are a few key factors that influence whether perishable foods like almond milk are safe to consume after being left out at room temperature overnight:

  • Type of packaging – Shelf-stable vs refrigerated
  • Time spent at unsafe temperatures
  • Temperature exposure

Let’s explore how these factors specifically apply to unopened almond milk when left out on the counter overnight.

Shelf-Stable vs Refrigerated Almond Milk

Almond milk is available in shelf-stable aseptic boxes that do not require refrigeration. This type uses a high heat pasteurization process called UHT (ultra high temperature) to sterilize the milk, allowing it to be shelf-stable for several months. The packaging is aseptic and specially designed to prevent contamination and spoilage.

Refrigerated almond milk is typically found in the refrigerated section of the grocery store in plastic bottles or cartons. It is processed using standard pasteurization at lower temperatures than UHT. Once opened, it requires continuous refrigeration to slow bacterial growth.

The key difference is that unopened shelf-stable almond milk can safely be left out at room temperature, while refrigerated almond milk cannot.

Time Spent at Unsafe Temperatures

Time and temperature control are essential for food safety. The “danger zone” for bacterial growth is between 40°F and 140°F. Foods should not be left out at room temperature for more than 2 hours as bacteria can quickly multiply.

Leaving refrigerated almond milk out on the counter overnight exceeds the recommended 2 hour window by several hours and allows the milk to warm to temperatures within the danger zone. Bacteria present in the milk prior to opening will rapidly multiply overnight, making the milk unsafe.

Temperature Exposure

Room temperature varies depending on climate and season. In some environments, room temperature may exceed 85°F, especially in summer months. At higher temperatures, milk left out overnight will warm more significantly, further increasing the risk of bacteria growth.

On the other hand, cooler room temperatures around 60-70°F will slow bacterial growth. However, the milk should still not be left out longer than 2 hours before refrigeration.

Safety Risks of Spoiled Almond Milk

Consuming almond milk that has been left out overnight poses some risks:

  • Food poisoning – Common symptoms include nausea, vomiting, diarrhea, fever, chills, stomach cramps.
  • Bacteria growth – Salmonella, E. coli, Listeria, Bacillus cereus, Staphylococcus aureus are possible contaminants.
  • Mold growth – Can occur from Aspergillus and Penicillium molds.

Groups at higher risk for foodborne illness include pregnant women, children, older adults, and those with compromised immune systems. Food poisoning symptoms can range from mild to life-threatening depending on the pathogen, amount consumed, and individual health status.

How to Tell if Unopened Almond Milk is Bad

With refrigerated almond milk, check for signs of spoilage before consuming after leaving it out overnight:

  • Smell – Milk may smell sour or abnormal if bacteria has grown.
  • Color – Milk may change to a yellow tint from white.
  • Texture – Milk may become grainy or lumpy if spoiled.
  • Taste – Spoiled milk may taste tangy, bitter, or unpleasant.
  • Expiration date – The date on the carton indicates when unopened milk expires.
  • Gas buildup – Blown out, bulging containers can indicate gas from bacteria.
  • Mold – Surface mold spots are a sign of spoilage.

Trust your senses. If anything seems off with the milk’s appearance, smell or taste, err on the side of caution and throw it out.

Precautions for Storing Almond Milk

Follow these guidelines for storing almond milk properly:

  • Purchase almond milk 1-2 weeks before the “best by” date.
  • Refrigerate promptly after purchase, ideally under 41°F. Keep shelf-stable and opened milk refrigerated.
  • Seal opened containers tightly and minimize exposure to air.
  • Use opened milk within 7-10 days.
  • Keep storage areas, containers and utensils clean.
  • Don’t let milk sit out for over 2 hours at room temperature.

What to Do If Almond Milk is Left Out Overnight

If you discover that the almond milk was accidentally left on the counter overnight, follow these steps:

  1. Check the temperature. If it still feels chilled, it may be salvageable if immediately refrigerated.
  2. Inspect the packaging. If it’s bloated or leaking, the milk is likely spoiled.
  3. Smell and look for signs of spoilage like an abnormal appearance, texture, or odor.
  4. If any sign of spoilage, throw the milk out. Don’t taste it.
  5. If no obvious signs of spoilage, the milk may be safe if immediately consumed. However, use extra caution or discard it.
  6. When in doubt, remember the 2 hour rule and throw it out. Don’t risk getting sick.


Can I put almond milk back in the fridge after leaving it out overnight?

No, it’s unsafe to refrigerate almond milk after leaving it out at room temperature overnight. Any bacteria present can quickly multiply once the temperature enters the danger zone between 40-140°F. Refrigerating will stop growth but does not eliminate toxins.

Is it safe to drink refrigerated almond milk a few days after the expiration date if unopened?

It’s generally not recommended to consume refrigerated almond milk more than 1 week past the expiration or “best by” date, even if unopened. The expiration date accounts for potential spoilage and quality deterioration. However, it may last a few days past the date if continuously refrigerated.

Can I freeze almond milk to extend the shelf life?

Yes, both opened and unopened almond milk can be frozen to extend the shelf life, ideally for up to 3 months. Thaw frozen milk overnight in the fridge before use. The texture may change after thawing but it remains safe to consume.

What temperature should almond milk be refrigerated at?

Almond milk should be refrigerated at 40°F or below. Most household refrigerators maintain temperatures around 37°-40°F. If possible, store milk on interior shelves rather than the door where the temperature variations can be higher as the door opens.

Can I mix leftover almond milk with fresh milk?

No, it’s unsafe to mix old almond milk with fresh milk. The older milk may contain bacteria that can transfer and contaminate the new milk, causing spoilage and foodborne illness.

The Bottom Line

Refrigerated almond milk should never be left out on the counter overnight, as bacteria can quickly multiply at unsafe temperatures. Shelf-stable milk is safe, but refrigerated milk may be hazardous if left unrefrigerated for over 2 hours. Always inspect milk and never consume if any sign of spoilage. Use proper storage methods like prompt refrigeration to prevent foodborne illness.

Almond Milk Type Safe to Leave Out Overnight?
Shelf-stable, unopened Yes
Refrigerated, unopened No
Refrigerated, opened No

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