The Shelf Life Of Your Morning Coffee May Surprise You

Photographed by Rockie Nolan.
By Leslie Stephens

It happens every afternoon: Around 4 p.m., I start to fade and begin considering my caffeine options, always landing on the abandoned, half-consumed coffee at my desk. Every morning, I brew a cup, put a splash of milk in it, take a sip or two, and then get distracted by my to-do list (looming deadlines are more effective motivators than caffeine, I've found). And, later on every day, I wonder, Can I still drink that? At what point does the potential risk outweigh the promise of caffeine? I turned to Google to find an (unofficial, but workable) answer:

What if the coffee has milk in it?
When properly stored and refrigerated, milk can last for up to a week past its expiration date, but milk should not be left at room temperature for more than two hours. So if your coffee has milk in it, play it safe and drink it while it's fresh.

Related: This Flow Chart Can Predict Your Coffee Order

Is the flavor of the coffee affected?
Just as coffee beans go rancid after about two weeks, brewed coffee can start to taste bad after about 30 minutes, or the time it takes for the coffee to cool. Then you have about a four-hour window before the oils in the coffee start to go bad, which further alters the taste. We'd like to state, for the record, that Oliver Strand — coffee writer and guest on our Burnt Toast episode about coffee — would not condone our drinking of cooled coffee. Our product manager Michael Hoffman, on the other hand, confesses to drinking day-old cups during the same episode.

Will microwaving the coffee kill bacteria?
While microwaves can kill pockets of bacteria, because they heat from the outside in, they often leave pockets of cold in the middle of food and drinks where bacteria can thrive. So they shouldn't be relied upon to kill whatever might be living in that cup.

Does the water in the coffee spoil?
Water can absorb flavors from its environment (especially if it's left in a particularly pungent place, like the refrigerator), but glasses of water are drinkable for weeks after they're poured. Unless water has something living in it, like flowers, it's difficult for bacteria to survive in it. Drink up.

So, is coffee safe to drink after several hours?
Black coffee should be safe to drink, though it probably won't taste all that good. If it has milk in it, make a fresh pot instead — but if you're determined to still drink it (as I often am), make sure to microwave it all the way through for an extra-safe 4 p.m. pick-me-up.
Advertisement

More from Food & Drinks

While some people might be trying to get you to delete your Instagram food pics, there are many, many more tinkering around in their high-tech laboratories...
Growing up, your parents may have told you to be grateful for your food, because some people are starving. Now, your own meals can actually help other ...
Coffee lovers of the world, get ready. We have news that might make even a die-hard caffeine addict à la Lorelai Gilmore jump up and down in excitement. ...
These out of this world doughnuts are topped with a vanilla galaxy. Oh, and did we mention that they only have two ingredients
DIY cotton candy ice cream that doesn't require an ice cream maker? Winning
Whether you're brunching or, uh, dinnering, etiquette is of the utmost importance when dining out. And no, we don't mean keeping your elbows off the table...
Once in college, I had a friend Google "how to make a grilled cheese," and I remember being completely baffled that someone would need a step-by-step ...
(Paid Content) Scrambled eggs for breakfast? Yawn. Standard-issue pancakes? Predictable. To effectively get us out of bed in the a.m., we prefer a morning ...
Once the vegetable our moms would have to beg us to try ("just a bite!"), today, we can't get enough of cauliflower. It practically defines the word ...
Great drinks, a perfect soundtrack, the perfect lighting: all these things can make a party good. But what makes a get-together memorable? The food. Once ...
A few months back, Zoe Bain went boldly where neither of us had gone before: She completely barred herself from anything takeout (yes, even coffee) for two...
Every time we log into Amazon, it feels like everything — movies, tech gadgets, and random articles of clothing — is competing for our attention. But, ...
S'mores are a messy dessert favorite. But why not skip the sticky situation and enjoy yours in a cone
This may be news to you, but living in New York is kind of expensive. But, while it may always be the land of $17 cocktails and unmentionable rents, the ...