Have you ever shared the same misfortune as I? Coming home after a short morning work shift to realize that you left your quart container of greek yogurt out on the counter? Oh the devastation!

I’ll be honest with you, I love yogurt, so being the boy I am I ended up capping it and putting it back into the fridge. My reasoning being that it was just too much to throw away. And a few days later my judgement call was thrown back into my face when I cracked the container open and got hit in the nose with quite the powerful odor from yogurt gone bad.

So, how long can yogurt sit out? According to most health codes, it is unsafe to consume yogurt and similar potentially hazardous foods after being exposed to temperatures above 40 degrees and under 135 degrees Fahrenheit for 4 hours or more. However, the higher the ambient temperature of the room is, the less time you have. So at room temperature you have a mere two hours.

Yogurt is one of those ancient foods that has been created for thousands of years before the U.S. Food and Drug Administration was created, and with it the highly nuanced laws governing food safety. In fact, a lot of these codes are being challenged by the growing nature of the artisanal food market. This is due to the very nature of what yogurt is as a food, and how it is created.

Yogurt, believe it or not, is a food that is actually cultured from milk with the use of two different bacteria cultures, lactobacillus bulgaricus and streptococcus thermophilus. Meaning that yogurt is a partially rotten milk byproduct, or fermented for those that don’t want to taste bile at this moment in time. You are welcome.

As a matter of fact, deliberately fermenting foods was one of the only ways our ancestors were able to store foods for long periods of time before refrigeration became the main form of food storage.

Also yogurt is a highly versatile foodstuff that has many more uses than a simple breakfast snack or addition, it can be used for things such as:

• Marinades, especially those of Greek and Mediteranean flavor profiles.
• Salad dressings when mixed with an oil of your choice.
• Make your own sorbet desserts.
• Make Labneh, a lebanese version of yogurt.
• Pasta Sauce, another Greek specialty.

Regardless of the fact that many modern consumers have grown away from the history and rich culture of the foods we eat, let’s cover the basic food safety guidelines set out by the powers that be.

How Long Can Yogurt Sit Out of the Fridge

The Food and Drug Administration is the authority on dairy products, and they have established some pretty good rules of thumb for food safety in the commercial kitchen environment and at home. For dairy products leaving food out for two hours is the maximum amount of time dairy products should ever be above 40 degrees. Note, that this is also temperature sensitive.

The easy explanation:

• If ambient temperature is between 40 and 90 degrees fahrenheit, then two hours is the maximum allowable time to maintain food safety.
• If ambient temperature exceeds 90 degrees fahrenheit, then one hour is the maximum allowable time to maintain food safety.

Yogurt, like many foods we eat, is a living food. Meaning that it contains a host of microorganisms that live within it. When yogurt sits out at these temperatures there are some microorganisms that are not so good for our health that favor these conditions. Which will give them an edge in reproduction over the bacteria that is safe and healthy for us to ingest.

For someone like myself who has a decent amount of experience working with living foods, such as: yogurt, kombucha, beer, live pickling, and kefir. I have a good sense of when too far is too far. It doesn’t quite hurt that I have a stomach made of cast iron either. For most though, who have days too busy to dive into the migraine of food science, these simple rules of thumb are enough.

Okay I can’t help myself, let’s dive into some history while I have your attention. This is very important concerning the nature of the western commercial diet.

A Brief History of Food Safety in America

With most food production having been moved out of the home and into the factory setting, rules and guidelines for food production and health safety have been established by governmental agencies in place. At the turn of the 20th century industrialization of food  began to cause major health concerns and problems for consumers at large.

One of the most notable commentaries of the food industry came in the form of Upton Sinclair’s novel “The Jungle.” This novel managed to grab the public’s attention with a ferocity and even went so far as to have President Theadore Roovesevelt invite Sinclair to the White House to discuss the content of the novel. This all eventually led to Roosevelt managing to pass federal laws reinforcing the U.S. Department of Agriculture’s ability to inspect and manage meat packing facilities. To this day, the Department of Agriculture is the authority on laws regulating the meat and poultry in this country.

Supposedly, it is safe to store foods like yogurt much longer than just a mere two hours at room temperature compared to its traditional creation and storage. This is why many health codes are being challenged over the United States as food preparers are diving into the rich history of the foods we eat, and for good reason, these foods got us to where we are today. 

Not just with yogurt, but foods and drinks like kombucha, prosciutto, cheese, and beer were traditionally made without the use of refrigeration units. If you are one of those home chefs looking to start an artisanal restaurant, look into HACCP, known as the hazard action and critical control point plan. While an expensive application, it may save you costs down the road.

Okay, back to yogurt at large.

Ways to Tell if Yogurt has Gone Bad

Remember me saying in the opening introduction how I made the mistake of storing yogurt I left out only to have to come back to bite me? Well just because I’m a bit brave doesn’t mean I’m always right. Apparently the conditions were just right to give some mold or fungus the edge to send my sense reeling. Which brings up my next point.

When it comes to food safety, use your senses, all five of them.

Check the Consistency

Have you ever noticed when you can a container of yogurt that you haven’t touched for a while in the fridge that some strange slightly off color liquid is starting to pool at the top? This liquid is called whey, which contains a large amount of the protein found in yogurt. This is often a sign that your yogurt delight is reaching its age limit. 

This is a good point to give it a visual and smell inspection, and dive a bit deeper into food science with me. If all seems well, no foul odors or looks, go ahead and mix it back together. You should notice that the yogurt closer to the bottom of the container has a thicker consistency than what is closer to the whey.

Which is basically labneh, just minus the salt.

Anything other than this is cause for concern and you should probably just toss the yogurt to be safe. For instance:

• A yeast infection is hard to notice due to the texture and color of yogurt, but will give yogurt a gel like consistency and will seem glossy. It will also produce gas that will cause a sealed container to bloat. 
• A mold infection will cause a gritty consistency.

Check the Smell

Okay this one should be fairly self explanatory. If it doesn’t smell like yogurt, slightly tart with whatever fruits or sugars should be in it, toss it. However, don’t you dare miss the opportunity to trick your roommate or significant other into smelling it before you do. And make sure your car is running first as well as having enough cash in hand for a new security deposit on an apartment and a divorce.

Check for Mold

Also when inspecting, keep a lookout for little black, brown, yellow, green, pink, or blue fuzzies that might be hard to see at first, I mean anything fuzzy These will typically grow on the surface, however, molds have something similar to a root system that grow under the surface if missed before or was accidentally mixed in. This can be hard to notice if you have a premixed cup of fruit yogurt. The big thing to come back to is grittiness in texture on that one.

Yeast is a hard infection to notice, that will come down to consistency and off-gassing as I noted above. Even if you see either of these symptoms, toss it.

Check the Expiration Date

Okay, so this one is a little tricky as well, and I hate to seem as if I am leading you down a rabbit hole. Even according to the FDA, the expiration date is still just a guideline. It is better to refer to it as the ‘Best if Used by’ date. The reason being for this is that the FDA and even the USDA are attempting to help consumers cut down on food waste by properly educating them about their food.

That’s why I impress upon you to use your senses, if you eat yogurt often enough, then you should eventually develop an inherent sense of what yogurt looks, smells, and tastes like.

Risks of Eating Stale Yogurt

While milk that has gone sour is likely to only make you gag, yogurt on the other hand produces a perfect agar like substance that a few species of harmful molds and bacteria can grow in. While it’s not favorable to salmonella or e. coli, there may be mold that even produces toxins that can cause severe gastrointestinal distress. For instance the company Chobai had an incident similar to what I am describing several years ago.

While some molds are crucial to the creation of some of the mold flavorful food and drink we have at our disposal, with yogurt this is not the cause. So it shouldn’t kill you, but you’ll probably end up needing some over the counter medicines.

What to Do if You Already Ate Stale Yogurt?

Unless you have a very sensitive gastrointestinal tract, one bite before you notice your error most likely isn’t going to affect you. However if you managed to choke down a bunch of it before noticing you may experience nausea and vomiting, but you won’t die from it. Unless of course you have an allergic reaction to whatever toxins were produced by the mold. So just to play it safe though and you do experience some reaction, go to the hospital and get checked out. It is always better to be safe than sorry.

Ways to Store Yogurt Properly

Whether you have store bought yogurt or have made yogurt at home, there are several ways in which you can store yogurt to increase its effective shelf life. If you bought a big ole’ tub of yogurt or have one of those packages of individual cups, it is best to not let it go to waste. I don’t know about you but i have gone hungry enough times to do my best to be mindful of food waste.

• If you have bought yogurt in individual containers and believe that in the foreseeable future some of them have the potential to go to waste, then you can freeze it. This can increase the shelf life of yogurt by 4 to 6 months. 

• If you have happened to make your own yogurt, use resealable containers such as ziplock bags or canning jars. Whatever container you go with just make sure it is airtight.

• If you are storing yogurt in the refrigerator, store it on the top shelf. This area is closest to the freezer section and is less susceptible to temperature changes.

• If you are lucky enough to have access to a cold cellar that regularly maintains a temperature of less than 40 degree fahrenheit then it is perfectly fine to store yogurt there, you lucky dog.
• If you have bought a bulk container of yogurt you should take what you believe you will use for the next week or so and place it into a separate container, and place what you want to save in the freezer. This will reduce exposure to fluctuating temperatures and cross contamination.
• One way to not store yogurt is in the door of the fridge, this area is susceptible to heat fluctuations quite often and may reduce the shelf life of the yogurt even if you haven’t opened it.

Final words

So, now that you understand what to look for when yogurt is beginning to go bad, how to properly store it, and some very simple recipes with what you can do with it, don’t you wanna go play with it right now? I know I do, and I’m currently putting in work to make a potato and black bean stew as I’m writing this.

A big takeaway of this article I want for you to have is the importance of self education and the food you eat. Harking back to Upton Sinclair and the revolution he started in food awareness, it is truly not best to leave your health in the hands of these large industrial food complexes. I could go on forever about corn sugar in modern foods and the decimation of the bee population. I in fact will be purchasing a beehive next spring.

Another thing is that it’s so easy and fun to prepare and cook your own exotic foods for friends and family that there isn’t much of an excuse not to. Imagine going to a potluck and busting out those labneh balls for dessert, if you are single, you won’t be for long. Either way, knowledge is power, go out and enjoy the broad world of food.