I’ve been guilty for making a pot of coffee in my drip machine in the afternoon, only to drink half of it…
Then coming back the next morning and just turning the heating plate back on to have another cup.
For the record it does not taste good, it definitely tastes good enough that I drank it anyway but it’s not something to make a habit of.
Coffee can sit out and still taste great for about 30 minutes, after that its flavor rapidly disappears and you end up with diner coffee. But it is generally safe to drink black coffee for 24 hours after it’s brewed if it’s sat out on a counter.
But I’m a coffee nut and even I will find myself drinking coffee that’s sat out for an hour or two.
Just this morning I was making a Moka Pot cappuccino and had some coffee leftover, I left it in the Moka pot on the still-warm hob and came back and drank it an hour later. It was still just warm enough and was still pretty damn good.
There are, however, better ways you can go about storing brewed coffee if that’s what you want to do because it can and will go moldy if it’s left unattended.
Can Brewed Coffee Go Bad
Black coffee can go moldy, it takes a long time but more than once I’ve accidentally left a small amount of coffee in the bottom of my drip machine’s pot only to come back to it and see little circles of mold sitting on the top of the water.
And that was nothing compared to how moldy the coffee grounds were in the top!
I’m happy to say that was before I started this blog back when my coffee habits were lackluster at best.
If you add milk to your coffee it will spoil much much faster, just as a glass of milk sitting out would do.
Luckily black coffee is almost sterile as it’s made with close to boiling water so it will stay safe to drink for quite a long time, the flavor, however, will be completely ruined, and if you’re looking for an Above Average Coffee then you’re going to want to make a fresh cup of coffee each time you want one.
That’s why I stick with 24 hours, as a rule, I’m sure I can drink it for a longer time after that but I don’t want to do that to myself.
But if I get into the car and there’s a cup of day-old coffee still there in a thermos, as long as it was a black coffee I’m probably going to take a drink of it.
It’s all down to personal taste and what you’re willing to do, some people refuse to use coffee beans that are more than 2 weeks old from roasting because the flavor starts to diminish. So to them drinking a coffee that’s gone cold would cause a panic attack.
But live and let live, there are loads of people who drink days-old coffee so if that’s what you want to do then just do it. I’m not judging (until you scrape the mold off, then I’m judging)
Can You Drink Day Old Coffee
I touched on this in the above section but if you’re skimming I thought I’d make it easier to find.
You can drink day-old coffee that’s been left to sit out. If it’s black coffee you can drink it cold but if it’s coffee with milk or creamer then you’re going to want to heat it before you drink it.
I’ve done this with a Starbucks Latte I took home, I got distracted and it sat half full on my counter overnight. The next morning I didn’t want to waste it so I poured it into a saucepan and gently heated it. Not till it boiled but just till it was a good hot drink and it was absolutely delicious.
Did it taste as good as when the barista made it? Of course not.
Did it taste good enough to be enjoyed as my morning coffee? Absolutely it did.
And this will work for most milky espresso-based drinks. If you’re drinking day-old espresso well you should just take a look in the mirror and decide if you’re the person who doesn’t have time to drink an espresso…
How Long Can Iced Coffee Sit Out
For Iced coffee, you can drink it 1-2 hours after it’s been made, or if you live somewhere hot you can drink it until all the ice melts.
Any more than that and you’re looking at a very watery and not very delicious room temperature coffee.
Will it be safe to drink? Of course, you’ll be able to get the same 24 hours out of it but because it was iced it really won’t taste very nice.
How To Store Brewed Coffee
If you’ve accidentally made way too much coffee and you just can’t face throwing it away then there are things you can do to stop it from going rancid.
1. Don’t Put Dairy In It
This is a big one, putting in any milk or coffee creamer quickly lowers the shelf life of your leftover coffee, because as I said before dairy expires much quicker, especially if it’s left out at room temperature so you’re going to want to keep it black if you’re looking to store it.
So make as much as you’re going to drink with dairy and leave the rest black.
I’m not sure why you would put milk directly into all the coffee, I for one would be quite horrified seeing somebody put milk directly into a pot of coffee. But still, once there’s milk involved drink it while it’s hot or just as it’s gone cold.
2. Put It In The Refridgerator
Seems an obvious one but pretty much everything will last longer if it’s in the fridge, and since you can’t salt your coffee like your would some meat your hunted 200 years ago probably best to stick with keeping it refrigerated.
It will still taste a little stale compared to when it was made fresh but it’s better than letting a load of cups of coffee goes to waste.
3. Use An Airtight Container
Anyone will do it, a Tupperware with a lid will do the trick nicely. Just don’t put your open mug into the fridge or you’re going to find that your coffee will start to taste whatever else happens to be in the fridge too.
And I can tell you that the essence of onion in your coffee is not a good time!
Does Coffee Go Bad In The Refrigerator
It absolutely will eventually, but it depends how you define gone bad, in terms of pure coffee taste it will happen more or less instantly but if you’re looking simply to avoid moldy coffee rather than stale coffee you’re going to have a lot more time.
Coffee will go bad in the fridge after 1-2 weeks if it was put in as soon as it was cold enough. It will however go stale pretty much as soon as you put it in.
So while it’s an option it’s not one I’d recommend, it just won’t give you that great cup of coffee.
And yes you probably know someone who’s 70 who’s spent all their life making a huge pot of coffee once every two weeks and leaving it in the fridge to take a cup at a time.
But it’s just not nice coffee they’re drinking, it’s hard intense harshly brewed coffee which is how some people like it but it’s not what we’re about here at this blog.
I’d personally leave coffee unrefrigerated overnight and drink it instead of keeping it refrigerated overnight and having it then.
In my opinion, it just tastes better.
But the debate rages on about the best way to store coffee and a lot of it comes down to personal taste.
How To Reheat Cold Coffee
We have a whole separate article on reheating coffee but I’ll give you the best 3 options you have here:
1. In The Coffee Pot
If you have a pot of coffee that’s been sitting out overnight, absolutely nothing wrong with just turning it back and letting it heat up in the pot.
It will taste darker, a little harsher, and more bitter, but overall it’s absolutely fine and it’s just so simple to do.
If it gets to the 2-day mark, I’d cut your losses and make a fresh pot, however.
2. In The Microwave
Again tried and tested. A lot of coffee snobs freak out at the thought of microwaving coffee, but there’s nothing wrong with it if you know what you’re getting in.
A pro tip, however, is to go 15 seconds at a time and stir it between each blast to make sure it doesn’t get overheated.
Not the end of the world if it does accidentally come to the boil but keep your chances high of having a halfway decent cup of coffee and nuke it gently.
3. In a Saucepan
This is the best option when it comes to heating coffee because you have the most control and can heat it without burning it.
There’s also something that makes the coffee nicer compared to a microwave that I can’t quite place…
But the main bonus is you don’t end up with a boiling hot mug that you can barely handle!
What Happens To Coffee That’s Left Out
There is basically a 3-step process that happens from the moment your coffee is brewed, starting with it touching the air.
Phase 1 – Oxidation
From the minute coffee comes into contact with the air it is under threat from its environment.
The air begins a process of oxidation in the coffee which is similar to why metals start to rust, the oxygen oxidates the coffee aroma, oils, and flavor compounds, degrading and destroying them.
This happens from the minute coffee is brewed which is why it’s always better fresh, but most people won’t start to notice for about 30 minutes.
Phase 2 – Flavors start to flatten
With this process of oxidation comes a slow flattening of the flavors, first the subtle flavors disappear, then the major flavors disappear and before you know it you’ve got a cup of diner coffee.
Which has its place but it’s so easy to make better than diner coffee at home.
And this process pretty much continues until the coffee drinks. But obviously, it won’t just taste like water at the end, it will always have a general coffee flavor, it just won’t necessarily have a nice coffee flavor.
Phase 3 – Mold
And after a long enough time has passed, 1-2 weeks of sitting on the counter usually, you’ll start to get mold appearing on the surface of your coffee. And it’s gross.
Just pour it all away, clean it thoroughly and start again.
How Long Can Coffee Beans Sit Out
It’s one thing to talk about how long brewed coffee can last, but what about roasted coffee beans?
Well, there is a ton of debate about this but…
Generally, you can let coffee beans sit out for 2 weeks before you notice a change in taste, but they will still taste good for 3 months.
If you are a self-proclaimed coffee connoisseur and you’ve developed a coffee palate that can distinguish the subtle flavors in a cup of coffee, then yes after 2 weeks you will notice a difference in the quality of the coffee.
But if you like coffee, or you love coffee and you like to make yourself a good cup then you can happily drink coffee for 3 months from the roast date and you won’t notice a huge difference.
I bought a 1kg bag of my favorite coffee beans 1 month ago today and I’m still happily drinking them. I opened up the bag and split it into smaller Tupperware that I leave unopened till I’m ready to start grinding at they taste great.
this is whole bean coffee, ground coffee will lose its taste faster but the proper snobs claim that happens 20 minutes after its ground…
So I’d stick to a max of 1 month for ground coffee and 3 months for whole bean coffee if you want to make your coffee last but still have it taste good.
But if it’s stored properly you could technically still drink it a year from when it’s roasted, just don’t expect it to taste very good!
If you find yourself too often in the position of picking up a cold cup of coffee then you’ve got a couple of options.
Cold Brew Coffee
If you find yourself with a cold coffee, then why not try out cold brew coffee instead? It can stay in the fridge once it’s brewed for 2-3 weeks and you can leave it out all day and still pick it up and drink it anytime.
It will taste nicer fresh when it’s poured but it keeps its flavor for longer compared to hot coffee. So while a fresh coffee is always preferred you might consider making cold brew, and at the very least you’ll have fun learning a new way to make coffee.
Get A Different Coffee Maker
Your other choice is to get a coffee maker specifically designed to keep coffee hot for longer, I’ve reviewed all the top choices here.
But basically, you want a drip machine that has a very well insulated carafe, if you’re used to making coffee in a French Press then you’re more stuck, you’ll just have to get better at making the right amounts each time you drink it!
So there you have it, there isn’t a set expiration date the way there is with the likes of coffee creamer but coffee can and will go bad if it’s left to sit out for too long.
But if you have day-old coffee and need a quick wake-me-up in the morning then you can go ahead and reheat it, I would and I run a coffee blog!
Do Coffee Beans Go Bad? (Here’s How To Tell)
Can You Freeze Coffee Beans and Grounds (Here’s How You Should)
Heavy Cream In Coffee (Let Me Convert You)
Can You Froth Creamer?
How To Make Black Coffee Less Bitter (Tips And Tricks To A Better Brew)
How Long Does Cold Brew Coffee Last?
How Long Does Coffee Last in the Fridge?