Food52's Leslie Stephens wondered herself if there were any risks to fighting the 4 p.m.



If you're merely seeking a caffeine injection, hours-old coffee will do the trick, though you probably don't want to wait more than a day — or more than two hours if there's unrefrigerated dairy involved.
If you're a coffee snob and will only drink the finest brews, however, your options are more limited, and you're better off brewing a new pot and drinking it within the first half hour.
As it turns out, the answer is more complicated than we thought, hinging on factors such as how old the coffee is and what was added to it.
I've done my best to distill all the information out there, both from Stephens' exploration and my own, into a handy guide on when to drink leftover coffee — but since I'm generally pro-coffee and anti-waste, my short answer is, yes. But hey, if leftovers are not your thing, brewing a new pot is also OK, because the general consensus is that coffee is good for you — and in some cases, the more you drink, the better (within reason).
One occurs at the age of 30 minutes, when the coffee cools and loses flavor.
The next is after about four hours, when the oils go bad and the coffee becomes more acidic.Ah, the age-old question: Is it okay to drink leftover coffee?Most regular coffee pots are way too big for one person to drink one morning alone, so it's bound to come up.For a collector who prefers to search and buy items out of the traditional - and sometimes expensive - antique retailer shops, a valid alternative way is to collect as much informations as possible about the style evolutions and patterns of the object he intends to buy.Furthermore it is necessary to adopt a rigorous and pragmatic approach, trying to avoid emotional factors which may affect the correct evaluation of the item.As an example we'll try to verify the authenticity of one of the most important pieces of my collection: an English George II Coffee pot dating 1745.