How long is it safe to drink coffee after brewed?
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.
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?
I'm curious too, considering a single pot of (any semi-normal) coffee isn't terribly expensive or difficult to make.
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.
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.
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.
If you don't want to drink leftover brewed coffee, water your plants with it. They will love it!
Regarding the flavor, and how long you have before it is ruined, that depends on a number of factors, such as the beans you are using (both what type and their roasting), the grind and the brewing methond, to mention but a few.
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.
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 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.
@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).
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: 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.
@Satanicpuppy: Milk that goes sour can sit for many days in moderate cool (until it gets moldy), just covered against insects - that's how it was kept drinkable in times before refrigerators. The taste is quite nice, similar to Kefir - note you MUST start with fresh, non-pasteurized milk (pasteurized develops some different, quite horrible kind of bacteria). Of course it's quite unsuitable for mixing with coffee - the taste, while pleasant, clashes with coffee badly, the two really don't go together well.
Agreed with this. We use a french press for our coffee, and whatever doesn't get drank gets poured into a large vessel and refrigerated to be used later as iced coffee. We've had it sit for more than 2 weeks with no issues at all.
I have a gut feeling that coffee actually helps preserving milk. That is, leave a glass of milk, and a cup of coffee with milk on the table, and the coffee with milk will stay drinkable longer. To say it another way, I'd feel comfortable drinking morning coffee left on the table when I get back home, but if it was milk, not so much.
It depends on if you have a heated or thermal caraffe. It the coffee sits on a heater, it will break down and become bitter. I read this somewhere, but can't remember when. A thermal caraffe will not have this same effect, so reheating the coffee in the microwave later in the day won't affect the taste too much. By the next day though, I always just brew a fresh batch.