Did you cook up a generous batch of coffee this morning, only to end up with plenty leftover? Could you finish it off in the afternoon, or will it go bad?
Ideally, we’d drink all of our steaming hot coffee in one go – but it’s not always possible. If you’ve ended up with leftover coffee, don’t throw it just yet. Your coffee may be able to sit out for longer than you think before it goes bad.
Here’s everything you need to know about leftover coffee, and how long you can drink it for after its been left out.
How Long Can Coffee Sit Out?
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Well, we can’t give you a definitive time frame. The answer depends on several factors, including the type of coffee you have, whether you’re using milk or creamer, and if it’s hot or cold brew.
In short, though, leftover black coffee will be fine for just under 24 hours. However, it definitely won’t taste as fresh as it did when you first made it.
As long as it has no additives, you can drink it for up to a day after you made it – good news for black coffee lovers!
However, any coffee that’s left out for longer than thirty minutes will start to lose its flavor. So, if you want to get the most flavor from your coffee, you’ll need to drink it ASAP.
Here’s a closer look at how long you can leave different types of coffee to sit out before they go bad.
Iced Coffee/Cold Brew
Iced coffee and cold brew lovers, listen up. There are a few different scenarios to consider here, and each one will affect how long your coffee will last.
With Milk and Creamer: If your iced coffee has milk or creamer in it, it may only be good for two hours at most. Sometimes, the temperature of the ice can buy you an extra 30 minutes to an hour, but either way, it’s likely to go watery when the ice melts. Creamer can also generate bacteria and mold. However, if you’re using a non-dairy creamer, you may be able to preserve it for 24 hours.
Black Iced Coffee: If you have a black iced coffee, it’ll be good to sit out for up to 24 hours. However, it will get pretty watered down, so we’d recommend refrigerating it.
Black Cold Brew: Cold brew doesn’t tend to last as long as iced coffee. Your leftover black cold brew shouldn’t be left any longer than 12 hours.
Cold Brew With Milk/Creamer: If you’re combining your cold brew with milk or creamer, it will have an even shorter lifespan. Dairy can spoil pretty quickly, so your cold brew with milk or creamer will go bad after around 2 hours. Non-dairy creamers can stretch for 12 hours.
What Happens When Your Coffee Goes Bad?
Unfortunately, the longer your coffee sits out, the more it will spoil. Like other foods and beverages left out at room temperature, coffee will also go through its own degradation process which will affect the taste, quality, and safety of your drink.
Oxygen has a big impact on the aromatic compounds found in your coffee.
When exposed to oxygen for prolonged periods, these compounds will start to generate a pretty “off” taste – in other words, your coffee will no longer taste like coffee, and it may start to taste acidic, sour, or rancid. That’s the worst case.
Best case, it will taste bitter and flat. Either way, it’s not going to be particularly pleasant.
Is Leftover Coffee Bad For Your Health?
Not only does leftover coffee start to taste bad, there are also some safety concerns to consider. If your coffee has been sitting out for too long (especially if it contains dairy), it may start to spoil and grow bacteria.
When you leave your coffee to sit at room temperature, you’re providing it with just the right conditions to grow mold and other harmful bacteria. It’s safe to say, drinking coffee that’s been left out for too long could leave you feeling a bit queasy.
However, this is only likely to happen if you’re drinking coffee that’s been left out for more than 24 hours. If you’re seeing any signs of bacteria growth on your coffee, PLEASE, bin it.
This advice is especially true if your coffee contains milk. Dairy products will spoil extremely fast. When milk is left out for too long, it experiences a chemical reaction that produces bacteria growth in your coffee.
So, if your dairy cup has been sitting out any longer than two hours, don’t drink it.
Will Microwaving Your Coffee Kill Bacteria?
So, what if your hot coffee has been sitting out for longer than the recommended time, but you want to reheat it? Will it be safe?
Although you may be tempted to microwave it and drink up, this process isn’t as efficient as you might think. Microwaving may reheat your coffee, but it also heats your drink from the outside in.
This means you’ll often leave colder sections in the middle of your coffee which allow bacteria to thrive.
Microwaving your leftover coffee is not an effective way to kill bacteria.
If its been sitting out for longer than the recommended time period, it may still be unsafe to drink, even after reheating.
The Bottom Line
So… how long can your coffee sit out? Well, it depends. If your coffee contains milk or dairy creamer, it will spoil much faster than black coffee. Iced coffee and cold brews also have different time frames, and cold brew, in particular, can spoil fast.
Remember to consult the guidelines above before drinking your leftover coffee. Room temperatures can create the perfect conditions for bacteria to thrive, so if you’re not careful, you may end up guzzling down more than just coffee.