Is Drinking Day Old Coffee Bad for You

Is drinking day old coffee bad for you? Does coffee go bad overnight? How long can a coffee sit out before it goes bad? Or should I dump the leftover coffee? Maybe all of you have faced such questions. Then what are the right answers for these questions? 

The answer is complicated. What’s in your coffee, your taste buds, and your level of desperation for caffeine all matters.  Below are some factors to consider.

1. What’s in your coffee?

If you’ve already added dairy and just left the coffee sit unrefrigerated overnight, you should dump it. Why? Dairy goes bad for more than two hours at room temperature. If your coffee has dairy in it, just drink it fresh. 

2. What if it is refrigerated?

If it’s refrigerated, it’ll last for at least a week, as long as you didn’t pre-dairy it. But if you’ve already added dairy, then you are dealing with that dairy shelf-life, and that isn’t very long at all. As to the day-old coffee with dairy added,  it’s potential to accumulate mold.

3. How old is the coffee? Is the flavor affected?

Just as coffee beans will go bad, so does coffee. Then how long can a coffee sit out before it goes bad? There are two milestones in the lifetime of a cup of coffee. It start to taste bad after about 30 minutes when it gets cooled and loses flavor. The next is about 4 hours – when the coffee oil goes bad and its flavor loses. So, as to the day-old coffee, it may become more acidic. 

4. Can I reheat it in Microwave?

Why not reheat the cold coffee in Microwave? Unfortunately, reheating coffee in the microwave won’t reverse the deterioration in taste. Also, if you try to kill some of the bacteria by microwaving it, you are out of luck. So you’re better off leaving your day old coffee alone.

So, is drinking day old coffee bad for you? The answer depends. Day old black coffee is safe to drink as long as it’s  refrigerated. But it probably won’t taste all that good. If your coffee has dairy in it, make a fresh pot instead.  All in all, it’s best for you to drink fresh coffee. If there are some circumstances that you have some leftover coffee, you’d better get it refrigerated. And drink it as soon as possible. Or you can make some coffee ice cubes with the leftover coffee.