In general, coffee shouldn’t be consumed more than 48 hours after it has been made (although this varies based on the beans and their roast date), but you might be wondering, “Can you drink day old coffee?”
It’s not actually harmful to drink day old coffee if you are okay with the taste and smell of stale coffee. That said, if you don’t like the taste or smell of stale coffee, it’s probably better to just make a fresh pot.
Can You Drink Day Old Coffee FAQ
There is no specific rule of thumb that says you have to waste your coffee. The truth is, the taste will probably not be much worse than the day before. As long as you do not store it for more than a few days and it is in a sealed container, most people will enjoy it.
However, there are some exceptions when it comes to re-heating your coffee that can produce a less than desirable taste. Beans that were used to make espresso, for example, should never be reheated because they could potentially taste bitter.
Another common exception is if you use milk in your coffee. If you can’t finish all of your coffee and need to store some for later, it needs to be refrigerated if you want to drink it the next day. Otherwise, the flavor will change dramatically after a single use.
For example, if you make an Americano with milk, you have about 1 hour to drink it. After that time, your best bet is to just pour yourself another cup.
Related: Coffee Tastes Metallic? Here’s why and what to do
Is it OK to Drink Coffee Left Out Overnight?
While it’s definitely not recommended, if you let a cup of cold coffee sit on your counter overnight (as long as there is no milk in it), it is safe to drink. Because coffee contains caffeine, which is highly water-soluble, most of it will have left your drink by now.
Even though some caffeine may still be present in an older brew—coffee beans and grounds start releasing their aromatic oils as soon as they are exposed to oxygen and light—the concentration should be significantly lower than when you first made it.
Unless you’re highly sensitive to caffeine, drinking coffee that’s been sitting out for several hours probably won’t cause any noticeable side effects. That said, if your stomach is sensitive or if you’re trying to avoid consuming unnecessary calories, toss out your day old coffee and make a new pot!
Related: Best 5 Cup Coffee Makers
Can Drinking Old Coffee Make You Sick?
If you leave coffee sitting for more than 48 hours, it could potentially make you sick. The sooner you drink your coffee after it’s been brewed, the better.
While there is nothing bad in sipping on a cup of day old coffee (unless it tastes off), we’re not always as sensitive to temperature changes and odor as others are.
So if your home smells like day old coffee and people come over to hang out with you, they might get a little queasy because their sense of smell is so strong. We also don’t recommend leaving your coffee for more than two days after brewing because mold can start to grow inside the container it was stored in. And, no one wants to drink mold.
A lot of people think that since coffee grounds are porous, they absorb bacteria from other foods or drinks left in them. That might be true if you leave a mug out overnight after adding milk or cream—but if your leftover black coffee is sitting there in a day old coffee pot it should be fine until tomorrow.
Re-brewing Coffee Beans or Grounds From the Day Before
There are three stages in brewing coffee – oxidation/blooming phase, solubilization phase, and emulsification phase – each of which contributes to different parts of taste. These phases occur when hot water is poured over grounds (grinds), soaking them and then extracting flavor from them.
During that time, there’s a lot going on chemically between your coffee grounds and water. In fact, it takes only 15 seconds for your coffee to start losing its flavor! That’s why it’s so important to brew your coffee immediately after grinding it. The longer you wait after grinding before brewing, the more flavor you lose during those first 15 seconds.
Steps for Re-brewing Coffee Beans
That being said, it is possible to re-brew coffee if you do it right. Here are some tips:
If your freshly brewed coffee is already cold by the time you get around to drinking it (or if you have leftovers), don’t throw out those grounds or beans! You can re-brew them into a fresh cup of hot java if you follow these steps:
- First, use an airtight container like a mason jar or Tupperware to store any leftover coffee in an airtight container. This will prevent oxygen from getting to your brew and oxidizing it.
- Next, add more water than you normally would when brewing coffee so that you dilute some of that stale flavor with fresh water.
- Lastly, add about one teaspoon per every two tablespoons of ground coffee and brew away!
While re-brewing might not produce as great a taste as that first cup did when everything was still fresh, there are ways to improve its flavor – especially if you know what’s going on during each stage of brewing and how best to manipulate them for better results.
The biggest tip we can give is don’t wait too long! As soon as possible after grinding your beans should be poured over hot water for optimal taste results.
Why Does Coffee Taste Stale After Sitting For a While?
Most coffee lovers know that a good cup of coffee only tastes as good as it smells. That amazing aroma is brought on by a chemical process called oxidation, which occurs in freshly brewed coffee within a few minutes after grinding, pouring, and brewing.
Oxidation also happens to cause staleness—hence why your morning cup doesn’t taste quite right after sitting on your desk for a few hours. While oxidation is good in coffee, too much oxidation can lead to stale flavors and flat-tasting coffee.
At its core, staleness is caused by compounds called phenols and ketones that form when proteins in coffee break down during exposure to oxygen. That explains why old or stale coffee often tastes stale: Those compounds are produced by proteins such as lactones, which are present in most coffees.
To avoid staleness, many specialty roasters employ strategies like using nitrogen gas packaging or sealing bags with one-way valves that release gases over time instead of letting them escape into the air. And while these methods do help slow down flavor loss, they don’t completely eliminate it.
To extend coffee’s shelf life, some people recommend storing beans in an airtight container in a cool and dry place away from direct sunlight and heat. That said, oxidation is unavoidable—and actually beneficial—when it comes to coffee’s complex flavors.
One thing you can do to mitigate staleness is to buy only as much coffee as you need for a week at a time (or less). If you want to keep your beans fresh longer than that, store them in an opaque container with a one-way valve so gases can escape but oxygen cannot get in.
Why Does Coffee Turn Bitter?
There are many theories as to why coffee turns bitter when left overnight, with most of them rooted in science. Many people believe that it has to do with sugar and carbohydrates—both natural components of coffee. When you brew a pot of coffee, you’re extracting all of these sugars and carbs from your beans.
The longer those sugars sit in your cup (especially if they’re exposed to air), they begin to ferment. Fermentation is what makes wine taste sour or beer taste bitter, and it also affects our morning coffee!
How to Tell If Your Cup of Coffee Has Gone Bad
If you’re working with hot coffee and don’t have time to drink it all at once, there are a few ways to tell if your cup of joe has gone bad. The first thing you need to look out for is a sour or bitter smell. If your coffee smells like spoiled milk or cream, then it’s best to throw it away.
Next, you should also check for mold and other unpleasant particles in your java—you can easily do so by making sure none of these things are floating in your cup of joe! Once you pour out any liquid that looks suspect, check the bottom of your cup—if it looks oily or grimy, be glad you didn’t take a sip!
Related: How Long Should You Percolate Coffee?
How to Properly Store Your Coffee Overnight
There’s nothing better than a cup of fresh coffee that has been stored in an airtight container and refrigerated, except maybe a fresh cup of coffee. If you don’t want to finish your cup right away, you can store it in your refrigerator until you are ready to drink it again.
When properly stored, coffee will stay fresher for longer than if left at room temperature. Many people feel that as long as it is still hot when served and not over-brewed, coffee is safe to drink after 24 hours in the refrigerator. Still, other people feel that 24 hours is too long because the flavor begins to change more quickly than that. Some say that if you store your coffee in an airtight container, then it can last up to two weeks before you need to throw any of it away.
How Long is Brewed Coffee Good For in the Fridge?
Brewed coffee will stay good in your fridge for about 48 hours. It’s fine to drink a cup or two days after it was brewed, but not any longer than that. After 48 hours, it starts to taste bad and it could be unsafe to drink at that point.
If you need to keep some coffee around for more than 2 days, freeze it in an airtight container instead of keeping it in your fridge. This will prevent any off-flavors from developing and ensure that your coffee stays fresh-tasting for up to a month.
If you want to store brewed coffee at room temperature longer than 48 hours, use a thermos or vacuum insulated travel mug instead of leaving it out on your countertop or in a regular glass or ceramic mug. These types of containers are designed to keep hot things hot and cold things cold without letting them get warm enough to spoil (which is what happens when they’re left out).
To be extra safe, make sure that if you leave brewed coffee at room temperature overnight that you put it into one of these containers first so there’s no chance that bacteria can grow on top of it and make you sick.
Related: Does Coffee Mate Need to be Refrigerated?
How Long Does Brewed Coffee Stay Fresh at Room Temperature?
If you leave a cup of coffee on your desk for more than 20 minutes, it’s already lost most of its freshness. The truth is there are lots of factors involved—like what kind of coffee you brewed, what kind of coffee maker you use, and if there is an added milk or cream—so your mileage may vary. But generally speaking, freshly-brewed coffee tastes best within 20 minutes of being made.