If it's refrigerated, it'll last for at least a week, as long as you didn't pre-dairy it.
Unrefrigerated, I wouldn't trust it for more than a day.
Coffee is a crappy growth medium and it should start out the next best thing to sterile, but, even covered, its going to start to get moldy.
Obviously if you add dairy, then you're dealing with that dairy shelf-life, and that isn't very long at all.
cooking.stackexchange.com/users/218/Satanicpuppy
Oh dear.
I wish I could answer this more anonymously.
I am notorious among my friends and family for drinking old coffee left in the mug in the center console of the car,often for a week or more.
Coffee is safe to drink, as far as I am concerned, as long as there are no fuzzy things growing on it .Today is Wednesday.
At present, I am drinking a mug of room temperature coffee from a pot I made Monday afternoon.
I make my coffee medium strength.
It tastes acidic although I have never run a pH test on it.
I use Chock Full O'Nuts brand when I can find it.
I don't use any additive, flavors or sweeteners.
I like it cold and black.
Nothing bad has happened to me that I can attribute to old coffee; I have been doing this for perhaps 40 years since college.
It was a habit I developed when I was very broke and never lost.
cooking.stackexchange.com/users/25802/piquet
I keep post-brewed coffee in the fridge in a big glass container.
It lasts for a long time; weeks!
My buddy is a chef, and at his restaurant they make liquor/coffee/martinis--the bar keeps black coffee in the fridge for weeks.
He insists it won't go bad for a month.
cooking.stackexchange.com/users/20550/Francois Balboa
I've drank coffee I've left out for a few days without any noticeable consequence.
It's always black, so I don't have any other components that go bad.
cooking.stackexchange.com/users/19984/Anon
coffee doesnt grow mold for quite some time..
try it youself; saturate some coffee beans and some grounds and let them sit out..
normally 4-5 days until mold grows on the grounds
.. 3 in warm conditions and since its diluted with all the water..
the first signs of mold I've actually seen are around 7 days in the pot.
cooking.stackexchange.com/users/17200/Joe
We have always kept coffee outside for a week, no problem.
No difference in taste.
But, now that the idea of keeping in the fridge has been planted in my ears, I will do that.
cooking.stackexchange.com/users/20822/TheMenace
If you freeze and make it as cubes then it will last very long.
In fact, I am gonna do this.
It's been a hassle to brew coffee every morning for a single person.
cooking.stackexchange.com/users/20900/Mimi
I brew a whole pot for myself and then refrigerate it (I drink it black).
It usually takes me about 5 days to finish the pot.
If I stretch it to 6 days, sometimes the last cup tastes "tinny" (metallic) and I don't enjoy it very much.
Funny thing is, the freshly brewed (first day)
cup is "just okay" as it tastes more tannic than the cups I have on day 2 through 5.
Having it "mellow" in the refrigerator seems to make it taste smoother to me and I enjoy it more.
I heat a single cup of it up in the microwave each morning.
From reading other's comments, I can see I'm not with the crowd as most people detect a negative taste from coffee after just a few hours from brewing.
Frankly, I like coffee most ways.
I like the $6 hand-poured stuff where you can really taste the beans, and I'm fine with most diner coffee too (as long as its not too watery).
I just feel its a waste to throw away coffee that's been brewed just because its not "fresh.
"
In my opinion, it just tastes different, but not "bad." To answer the actual question; I don't really know how long its safe, but almost all food is safe in the refrigerator for several days (as long as its not been sitting out too long) and in my years of experience with coffee, I feel comfortable with keeping it up to a week.
cooking.stackexchange.com/users/22668/lavenderchartreuse
I believe that the process that you use in brewing and storing your coffee can make a difference.
I have a coffee maker that you load with whole bean coffee and clear, cold water.
Press a button and the coffee is ground and water drips through it and a filter into a vacuum bottle type container.
It stays warm for hours, and when it is no longer hot enough for me
I place a cup full in the microwave to heat up.
It lasts for days with no deterioration.
If I forget to dump the filter with the ground coffee in it, after a few days it will begin to develop mold.
I also found that if I want to you have cold coffee.
I can store the brewed coffee in a glass closed container in the refrigerator and simply add half-and-half and ice cubes to it when I'm ready to drink by the glass.
cooking.stackexchange.com/users/26879/BEN
How many hours/days would you recommend to drink coffee (after brewed) and consider it safe? (For example if you don't want to waste it). What is the difference if it is refrigerated or not?  The question is not about flavor since (I think) it is probably ruined after at most a couple of hours.
How long is it safe to drink coffee after brewed?
cooking.stackexchange.com
<food-safety><storage-lifetime><coffee>
cooking.stackexchange.com/questions/17225
cooking.stackexchange.com/users/7214/Javier
Plain black coffee can last for a week or more in the fridge, or longer in the freezer, but is less durable when left out. It will grow mould after some time, but usually not for a few days at least. You can keep coffee in or out of the fridge for several days without any problem.
In the fridge it will last for a week or more without any deterioration. It will last for many days without growing any mold.