What happens if you drink oat milk that has been left out?
Introduction
Oat milk has become an increasingly popular plant-based milk alternative in recent years. Made from soaked and blended oats, it has a creamy, nutty flavor and can be used in many of the same ways as dairy milk. However, there are some important food safety considerations when it comes to storing and consuming oat milk, especially once opened. Leaving oat milk out at room temperature creates an environment where bacteria can multiply quickly, potentially leading to foodborne illness if consumed. In this article, we’ll take a closer look at what can happen if you drink oat milk that has been left out and how to store oat milk properly.
How Long Can Unopened Oat Milk Last at Room Temperature?
Let’s first look at how long unopened, shelf-stable oat milk can be left out before it’s opened:
| Room Temperature | Time |
|---|---|
| Pantry/Cupboard (up to 77°F) | Best by date on package |
Unopened, shelf-stable oat milk has undergone ultra high-temperature (UHT) pasteurization and can be stored at room temperature until the best by date printed on the package. Once opened, it should be refrigerated.
The shelf life of refrigerated oat milk in an unopened container is also printed on the package, usually about 7-10 days from the packaged date.
How Long Can Opened Oat Milk Last Unrefrigerated?
Once opened, oat milk has a much shorter shelf life if left unrefrigerated. Here are the guidelines:
| Room Temperature | Time Before Discarding |
|---|---|
| Counter Top (77°F) | 2 hours |
| Hot Summer Temps (90°F+) | 1 hour |
The warmer the temperature, the less time opened oat milk can safely be left out before bacteria multiplication becomes dangerous. Best practice is to refrigerate opened oat milk immediately after use.
Why Does Oat Milk Spoil Faster Once Opened?
There are a few reasons why oat milk spoils more quickly once opened:
- Exposure to oxygen – When sealed, the packaging protects the oat milk from oxygen exposure. When opened, oxygen can interact with the proteins and fats in the oat milk, causing faster spoilage.
- Contamination – Hands, utensils, etc can introduce new bacteria into the oat milk when transferring from container to glass.
- Temperature fluctuation – Once opened, the oat milk is subjected to more temperature variability if left on the counter instead of refrigerated, contributing to spoilage.
For optimal freshness and shelf life, keeping opened oat milk consistently chilled helps slow bacteria growth.
What Are Signs That Oat Milk Has Spoiled?
Oat milk that has been left out too long and spoiled will show the following signs:
- Change in color – Fresh oat milk is opaque white. As it spoils, it may turn slightly yellow or brown.
- Curdling – You may see clumps or curdled chunks in spoiled oat milk.
- Off smells – Rancid, sour milk smells indicate spoilage.
- Off tastes – Spoiled oat milk will taste sour or bitter.
- Gas bubbles – Carbonation or fizzing when you pour it.
If you notice any of these warning signs, the oat milk should be discarded.
What Types of Bacteria Grow in Spoiled Oat Milk?
Several types of dangerous bacteria can multiply in oat milk left unrefrigerated for too long:
| Bacteria | Type | Risks |
|---|---|---|
| Salmonella | Gram-negative rod-shaped bacterium | Salmonellosis causing diarrhea, fever, cramps |
| Listeria monocytogenes | Gram-positive bacterium | Listeriosis with flu-like symptoms |
| Staphylococcus aureus | Gram-positive coccus bacterium | Intoxication with vomiting, diarrhea |
| Bacillus cereus | Gram-positive rod-shaped bacterium | Food poisoning, nausea, vomiting |
These foodborne pathogens thrive on dairy products at room temperature. Refrigeration helps slow their growth.
What Are the Dangers of Drinking Spoiled Oat Milk?
Drinking oat milk that has spoiled from improper storage comes with serious health risks:
- Food poisoning – Pathogens can cause vomiting, diarrhea, abdominal pain, fever, chills, nausea.
- Infections – Bacteria like salmonella or listeria can lead to dangerous infections.
- Toxins – Spoiled milk contains toxins that can cause cramping, headaches, vertigo.
- Long-term complications – Bacteria like salmonella increases risk for reactive arthritis, irritable bowel syndrome.
Food poisoning usually resolves on its own within 48 hours, but infections or long-term issues can develop from certain pathogens. Seek medical treatment if severe symptoms arise.
Who is Most at Risk From Spoiled Oat Milk?
Certain populations have heightened risk for complications from consuming spoiled or contaminated oat milk:
- Young children
- Older adults
- Pregnant women
- Those with compromised immune systems
- Individuals with chronic diseases like diabetes, cancer, kidney disease
Their vulnerable immune systems have more trouble fighting off foodborne pathogens. Healthy adults may just experience a day of acute food poisoning symptoms, while at-risk groups could face hospitalization from severe infection.
How to Store Oat Milk Correctly
To avoid spoilage and safely store oat milk:
- Refrigerate after opening – Keep oat milk chilled at 40°F or below.
- Check “use by” date – Don’t exceed label date after opening.
- Keep container sealed – Replace cap tightly after each use.
- Use clean utensils – Don’t introduce new bacteria into the carton.
- Keep refrigerated during use – Don’t leave out on the counter in between pouring glasses.
Also, check for any signs of spoilage before consuming, like odor or texture changes. When in doubt, throw it out.
Can Spoiled Oat Milk Make You Sick If Cooked?
Some people wonder if cooking oat milk that has been left out can kill any potential pathogens present. However, it is not recommended to consume oat milk that has shown signs of spoilage, even if cooking it.
Reasons why:
- Heat may not kill all bacteria present
- Toxins can persist even with cooking
- May impart unpleasant flavors into recipes
- Not worth risking foodborne illness
The safest practice is to fully discard any spoiled milk, including oat milk. Cooking does not necessarily make it safe for consumption again.
Should You Smell/Taste Test Oat Milk Before Using?
It’s smart to do a quick smell and taste test of your oat milk before using or consuming it. Your senses provide early warning signs of spoilage:
Smell – Does it have a sour, rancid or off odor? Fresh oat milk smells mildly sweet.
Look – Any change in color or consistency? New curdling or separation is a red flag.
Taste – Sip a small amount. Rancid, bitter or sour flavors indicate spoilage.
Your instincts provide the best guidance. If anything seems “off” about the milk’s look, smell or taste, play it safe and throw it away.
How Long Does Food Poisoning Last From Spoiled Milk?
If you accidentally ingest spoiled oat milk or other dairy milk, how long will the food poisoning last? Here’s a general timeline:
- 30 minutes to 8 hours – Symptoms start to develop. Nausea, stomach cramps, diarrhea.
- 24 hours – Vomiting may begin and diarrhea worsens. Fever possible.
- 48 hours – Symptoms peak in intensity. Fatigue, headache, body aches.
- 72+ hours – Symptoms gradually improve and subside over a couple days.
Complete recovery can take 3-7 days depending on severity. See a doctor if symptoms don’t improve after 72 hours, or if bloody stools, prolonged vomiting, high fever or other serious issues develop.
Conclusion
Drinking oat milk that has been left unrefrigerated for more than 2 hours carries significant risk of foodborne illness. Spoiled oat milk may harbor dangerous bacteria like salmonella, listeria, staphylococcus or E. coli. Consuming contaminated oat milk can lead to food poisoning symptoms, or even serious infections in at-risk groups. Always refrigerate opened oat milk immediately and check for signs of spoilage before consuming. Discard any oat milk that smells, looks or tastes off. Following proper storage and handling prevents growth of pathogens that makes oat milk unsafe to ingest. Be vigilant with opened dairy-alternative milks to enjoy their benefits without risk of foodborne disease.
