How Long Can Coffee Sit Out? Timers at the Ready!

In an ideal world, we’d all be able to drink our morning coffee immediately, but the day doesn’t always go as planned. Still, leftover coffee doesn’t always mean bad coffee. With that in mind, how long can coffee sit out before it’s no longer safe to drink?

In an ideal world, we’d all be able to drink our morning coffee immediately, but the day doesn’t always go as planned. Still, leftover coffee doesn’t always mean bad coffee. With that in mind, how long can coffee sit out before it’s no longer safe to drink?

Regular Coffeeness readers will know I always recommend brewing coffee fresh and drinking it right away. However, that day old coffee sitting in the coffee pot might prove too tempting to resist. In this article I’ll discuss what you should know before taking a sip. Let’s get started!

Overview: How Long Can Coffee Sit Out?

The lifespan of your brew depends on a variety of factors, such as whether you’re drinking hot coffee, iced coffee or using milk or creamer in your cup of joe. Keep in mind that cold brew and iced coffee aren’t the same, although you may hear those terms used interchangeably. 

I’ll get into the specifics below, but if you’re just looking for the CliffsNotes, a cup of black coffee is going to stay drinkable the longest at just under 24 hours. Of course, that doesn’t mean your black coffee will taste as great as it should. Still, as long as it’s free of additives and hasn’t been touched, it’ll be safe to drink for up to a day.

If you’re purely interested in how long coffee can sit out before it loses flavor, the answer is thirty minutes. Any longer than that and iced, hot or even what’s in your cold brew coffee maker is going to start losing its delicate aroma and flavor compounds. 

Iced Coffee from the Mr.Coffee Iced Coffee Maker.

How Long Can Coffee Sit Out? Different Scenarios

Since there are so many factors that contribute to how long coffee can sit out, let’s look at a few of these scenarios in detail. 

Hot Coffee

Fresh, hot steaming Coffee in a White Cup.
  • Hot black coffee: At normal room temperature, black coffee can last up to 24 hours before you’ve got to worry about it spoiling. However, that doesn’t mean it won’t be stale. Just thirty minutes in, plain black coffee will start to lose its flavor. 
  • Hot coffee with milk: If you’ve added milk to your black coffee, its lifespan decreases significantly. Any hot coffee that includes milk is only going to be safe to drink for around two hours at room temperature. This includes any milk-based espresso drink you might leave out, such as a cappuccino or latte macchiato. Milk spoils quickly, and it’ll get the curdling party started before you know it! 
  • Hot Coffee With Creamer: If you’re using liquid creamer that needs refrigeration, it’s still a dairy product and won’t last more than two hours out in the open. However, a non-dairy creamer that doesn’t need to be refrigerated is usually safe to drink for up to 24 hours. 

Iced Coffee and Cold Brew

  • Black Iced Coffee: Black iced coffee is essentially hot brewed coffee with some ice. As long as it’s free of additives, plain iced coffee will be fine to drink for up to 24 hours. That said, don’t be surprised if it turns into a watered-down mess within an hour or two. 
  • Iced Coffee With Milk: No shocker here, but iced coffee with milk is only good for two hours at most. The added ice might buy you a little time before the milk spoils, but you’re still facing down a watery drink that’s going to curdle. 
  • Iced Coffee With Creamer: If you drink iced morning coffee with liquid creamer after two hours, you may end up finding a special addition to your cup: bacteria and mold. For non-dairy or powdered creamers that don’t require any refrigeration, the lifespan will be closer to 24 hours. That is, as long as you haven’t added anything else to the cup. 
  • Black Cold Brew: Even without additives, cold brew tends to have a shorter lifespan than regular iced coffee, so ditch it if it’s been left out for more than 12 hours. Your cold brew may not “go bad” right away, but I can guarantee the taste won’t be great. 
  • Cold Brew With Milk: Given how quickly dairy products spoil, it shouldn’t be a shocker that any cold brew with milk can only sit out for two hours before it expires. 
  • Cold Brew With Creamer: For liquid creamers that spend most of their time in the fridge, you’re looking at no more than two hours  – and only 12 hours if you’re using non-dairy or powdered creamer. 

The Degradation Process

The longer your coffee sits out in the open, the more it’ll go through the degradation process. That might sound a little science-y, so here’s the gist: oxygen affects the highly volatile aromatic compounds in your coffee and these aromas will escape into the air. 

With enough time, the oils in your coffee will begin to oxidize and they’ll start to produce a rancid taste. I’m hoping that just reading that will convince you to always brew fresh!

Arne is Enjoying a Fresh Cup of Coffee.

The end result? Coffee that’s stale is likely going to taste bitter and flat. Next up, we’ll get into some of the safety concerns for drinking hours old coffee, as well as stale coffee with milk. 

Safety Concerns

Milk might go bad, but why isn’t it safe to drink day old coffee that’s been sitting out? Black cold brew or hot java might not curdle or “spoil” the same way that dairy products do, but they will grow mold and bacteria if they sit out long enough. 

Ever waited a few days to clean out the coffee sitting in your drip coffee maker? If so, you’ve probably seen the start of mold growth. Although you may use hot water to brew coffee, leaving it out at room temperature gives mold the perfect moist environment it needs to thrive

This can happen with coffee from a coffee maker, coffee grounds or even green coffee beans that haven’t been roasted yet. Paying attention to the time frame within which coffee is still safe to drink is important. Otherwise, you might find yourself guzzling down more than just coffee. 

Coffee With Milk

Making a Latte Macchiato.

Black coffee definitely has a longer shelf life, but introducing milk or liquid creamers is going to rapidly shorten that timeframe to a few hours. This is because milk spoils quickly once it’s no longer being stored within the right temperature range

When milk sits out too long, it sets off a chemical reaction that leads to rapid bacteria growth in your cup of coffee. That espresso macchiato might’ve been a flavorful cup initially, but give it more than a few hours, and you’ll have a petri dish for bacteria. 

Here’s something else to keep in mind. Although coffee with milk or creamer is usually safe to drink for up to two hours, everything changes as the mercury begins to rise. Room temperature is one thing, but letting your milk sit out on a hot summer day won’t do your tummy any favors. 

Other Considerations

Besides the safety concerns, there are a couple of other reasons you may want to store your coffee in the fridge or a sealed container. The biggest one is bugs. You may not be interested in a moldy cup of joe, but that doesn’t mean cockroaches, rodents or other pests won’t be

Most of these pests aren’t picky about their food source, and they’ll have no problem taking a couple of sips of the coffee you’re letting sit out overnight. 

On that same note, leaving coffee out could be an attraction for your pets too. Some dogs will consume anything, including moldy coffee. Caffeine is already a bad choice for most animals, and the bacteria that’s festering in your cup won’t do them any favors either.

Verdict: How Long Can Coffee Sit Out?

There may be days when you don’t feel like going through the process of brewing coffee, so how long can coffee sit out? You shouldn’t consume black coffee after 24 hours, and if there’s milk involved, you don’t want to test your luck after two hours. 

Ultimately, I never recommend letting your coffee sit out too long. In addition to the health and safety concerns, it’ll taste bad, have an unpleasant smell or have plenty of harsh bitterness from the degradation process. I mean, a quick caffeine fix just isn’t worth all that nastiness!

Fresh coffee or a fresh cup is always going to be the healthier and better tasting alternative to day old coffee. While I’m on the subject, always buy quality coffee beans from an independent roaster and grind them right before brewing!

Do you ever drink coffee that’s been sitting out? Your secret’s safe with me! As always, I look forward to reading your questions and comments!

How Long Can Coffee Sit Out? FAQ

While any fresh pot can start to taste stale after thirty minutes, black coffee shouldn’t go bad unless you’ve let it sit out overnight. Cold coffee and cold brew concentrate are a little more fickle, so you’ll want to consume them within twelve hours (assuming you don’t add milk). 

As long as your house is at normal room temperature, it’s very possible for most brewed coffee to become a petri dish for mold overnight. 

The oxygen in the air is what causes the breakdown of those sensitive aroma components. The flavor begins to deteriorate within thirty minutes, regardless of how great your coffee machine or French press is. 

I’m no doctor, but you shouldn’t have to worry about the transmission of COVID from your leftover coffee. That being said, if you’re going to drink coffee that’s full of mold or curdled milk, I wouldn’t expect it to be easy on your stomach. 

The answer is a big, fat no here. Regardless of how tasty your store brewed coffee, diner coffee or fresh pot might’ve been to begin with, leftover java tends to be bitter and rancid. 

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