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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.

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    I'm a bit curious about what use you have for rancid coffee which isn't yet moldy. Given that leftover coffee at room temperature will be rancid within a couple hours (shorter if it's warm), what are you going to do with it, anyway?
    – FuzzyChef
    Aug 28, 2011 at 21:29
  • I'm curious too, considering a single pot of (any semi-normal) coffee isn't terribly expensive or difficult to make.
    – rfusca
    Aug 28, 2011 at 21:51
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    I can think of a couple of times when I wanted a cup of coffee and only had morning-brewed coffee available. Now, I wonder if you find the taste of coffee after a couple of hours intolerable or just a little spoiled, and whether you prefer 'rancid', but otherwise good quality brewed coffee, to bad instantaneous coffee ;). It is of course a situation to avoid; I just wanted to at least know, in case somebody did happen to be in comparable circumstances, the safety considerations to take into account.
    – Javier
    Aug 30, 2011 at 1:41
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    There are these coffee machines that drip coffee into the jug slowly, and keep the jug warm - if the demand for coffee is low, it can sit many hours, or a mix of fresh and old can be maintained for days.
    – SF.
    Mar 11, 2013 at 14:46
  • I've left a latte in the car for about 20 hours (with the car heated up by the sun in the afternoon). While drinking it was probably not a good idea, it didn't smell bad or give a stomachache, and still tasted good.
    – Muz
    Mar 13, 2013 at 3:38

9 Answers 9

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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.

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    It's probably the pasteurization, but single or double cream usually lasts several weeks here, on its own. No idea how long it lasts in coffee and I don't plan on finding out...
    – Aaronut
    Aug 28, 2011 at 20:44
  • @Aaronut Dairy left in a coffee mug on the counter is ... interesting after a few hours, nevermind days. No idea if it is safe to drink, but it starts to make pretty patterns. I'd think that it would be fine in the fridge, though.
    – Adam Lear
    Aug 29, 2011 at 3:17
  • @aaronut: Yea, they do a special type of pasteurization (UHT: Ultra High Temp pasteurization). Given the right sort of packaging, that stuff can sit on the counter for 6 months and be perfectly fine. Lot of times kid's lunch milk boxes are done like that, and cream, and high end organic milk are often done that way too (having your milk last a month is awesome. I can't remember the time I had milk go bad on me). Once it's open and on the counter though, it grows stuff almost as fast as regular milk (regular milk has a head start, so it wins, but they're both bacteria friendly). Aug 29, 2011 at 13:23
  • My understanding was that the lactobacillus in milk competes with (and wins against) most other bacteria, so if it's pasteurized and thus not initially contaminated with other bacteria, not much else can grow. I could be wrong, of course. I believe that milk is still safe even after it curdles and goes sour, it's just not very pleasant.
    – Aaronut
    Aug 29, 2011 at 22:22
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    @aaronut: Somebody call guinness...Aaronut is less cautious about leaving a food out than Satanicpuppy ;) I honestly have no idea; I just find sour/clotted milk to be yucky. Though I love yoghurt and sour cream. Aug 30, 2011 at 0:41
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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.

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  • Perfect! Mine's is a little bitter right now, but nothing impotable.
    – Aditya M P
    Nov 17, 2014 at 8:31
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    Don't worry piquet, I love you ;-) and a big +1 for "just like Dick Cheney's first heart"
    – Spike0xff
    Jun 15, 2015 at 16:18
  • You're my hero of the day who has made me feel better despite your unscientific answer.
    – gunit
    Dec 17, 2018 at 17:18
  • Yeh this is basically correct. I mainly make espresso milk drinks but after decades of making those, and storing green beans and roasted beans, I can tell you that coffee is not appealing to rats, cockroaches or bacteria at any point.
    – goboating
    Nov 18, 2019 at 19:36
  • @piquet, pre-diaryed meaning?
    – Pacerier
    Jun 11, 2020 at 14:41
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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.

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    what if we don't have any fridge? any idea on the optimum room temperature to keep coffee for a week?
    – iamgr007
    Aug 1, 2016 at 6:42
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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.

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    Just because a dog hasn't bit you yet, doesn't mean it won't bite you tomorrow if you continue to engage in risky behavior. While coffee is not especially perishable, over days it will mold.
    – SAJ14SAJ
    Sep 2, 2013 at 7:21
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    That particular dog has not bit me since roughly 1968 when I was in college and so broke that throwing out un-drunk coffee was a luxury.
    – piquet
    Jul 16, 2014 at 17:26
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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.

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  • Having a cup of brewed coffee and having a cup of water and coffee grounds are not really the same conditions. If you were to do the experiment, why not just use actual cups of brewed coffee?
    – Jay
    Mar 10, 2013 at 22:45
  • I've done this experiment many times, unintentionally. it takes about 7 days before mold starts to grow on brewed coffee, but then rapidly gets worse
    – TJ Ellis
    Jul 13, 2014 at 15:45
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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.

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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.

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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.

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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.

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