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I made a fantastic brewed coffee at home yesterday, then got utterly distracted playing TikTok with my daughter and ended up letting it sit for almost an hour.
This got me wondering – how long can coffee sit out before it either doesn’t taste as good or is no longer safe to drink?
I have the answer after speaking with professional baristas, researching medical facts online, and confirming with other coffee experts.
How Long Can Coffee Sit Out?
Most coffee experts agree that for maximum flavor and aroma, coffee can sit out for up to 30 minutes at room temperature before you drink it. After 30 minutes of sitting out, the coffee flavor will degrade due to oxidation processes, where aromatic compounds from coffee deteriorate due to exposure to oxygen.
Beyond the initial 30 minutes, the length of time brewed coffee can sit out depends on whether it is a black coffee, cold brew, or milk-based coffee, whether it was stored in a fridge or at room temperature, and whether it was stored in an airtight container.
| Coffee Type | Sit out at room temperature | Safe to drink | How long can coffee stay in the fridge? |
|---|---|---|---|
| Brewed coffee | 0 – 0.5 hrs | 0 – 24 hrs | 3 – 4 days |
| Brewed iced coffee | 1 – 2 hrs | 0 – 24 hrs | 3 – 14 days |
| Milk-based coffee drink | 0 – 0.5 hrs | 0 – 0.5 hrs | 0 – 2 days |
How Long Can Coffee With Milk Sit Out?
Coffee with milk should be consumed within 30 minutes of brewing for the complete flavor profile and within 1 to 2 hours of sitting at room temperature before the milk spoils and becomes unsafe to drink.
According to US Dairy, milk should not sit out of the fridge for more than 2 hours or one hour in hotter climates where the ambient temperature is at or above 90 degrees Fahrenheit. Beyond these 1 to 2 hours, bacteria can start to grow, and your coffee is no longer safe to drink.
You may also like: How Long Can Coffee Creamer Sit Out?
This free cheat sheet will improve your coffee brew by providing quick information on brew ratio, grind size, optimal brewing time, and more.
How Long Can Iced Coffee Sit Out?
Iced coffee can sit at room temperature for at least 2 to 3 hours after the coffee is brewed and still be safe to drink. If your cold brew coffee contains ice cubes, then consider that your coffee will be watery and not as tasty as the ice melts.
If your cold brew contains milk, you should consume it within 1 to 2 hours.
How Long Can Coffee Beans Sit Out?
For ultimate freshness and a thick, rich crema, coffee beans can sit out for up to 2 weeks at room temperature, after which the quality of the beans will begin to degrade.
If the coffee beans are stored in an airtight container or vacuum-packed, they can last up to 3 months without compromising the flavor profile.
Why Does Coffee Taste Stale After Sitting For a While?
Oxidizing causes the staleness in brewed coffee. The coffee’s signature flavors are formed from volatile aromatics, which can quickly oxidize if you let your coffee sit out exposed to oxygen.
In coffee making, the process starts with the beginning stage of an intricate chemical reaction. When hot water evaporates from your coffee, it releases a strong scent that fades the flavor of its oils and aroma.
That’s why the ideal water temperature for brewing coffee is between 195 – 205F. Boiling water will over-extract the coffee leaving a bitter brew.
Aromas will also fade rapidly at high temperatures as the oxidization process occurs faster. That means a cold brew concentrate, for example, will stay fresh for longer than a morning coffee made with a French press or coffee maker.
Is Day-Old Coffee Still Drinkable?
Day-old coffee is still drinkable; however, the brewed coffee will not smell as delicious as freshly brewed coffee and might leave a bitter taste on your tongue.
It should also be noted that this rule of thumb applies to black coffee drinks. Any coffee drink that includes milk should NOT be consumed if it has been left out for more than 2 hours at room temperature because bacteria will rapidly grow and would no longer be safe to drink.
Bad Milk
For safety, milk must stay at an average temperature of 4.3°C. Any increase in temperature in milk is likely to result in rapid bacteria reproduction. Once the bacteria reproduction has begun, consuming it can be dangerous for you and cause serious health consequences.
If milk has been added to your coffee drink, the maximum safe sitting time will be about a half-hour.
Based on USDA recommendations, the same rules apply to oat milk because the bacteria spread in the milk. This applies to refrigerated or shelf-stable oat milk once it has been opened.
The Mold Stage
When deciding if day-old leftover coffee is safe to drink, bacteria growth is an essential consideration. Fortunately, plain black coffee isn’t considered a particularly hazardous food,
After about a week of being left to sit out at room temperature, brewed coffee will start to grow mold. The mold development rate will be restricted because plain black coffee contains minimal protein or carbohydrates, so it can’t support rapid microorganisms growth.
A cup of day-old black coffee left to sit at room temperature is unlikely to grow mold, making it unsafe to drink. If the black coffee contained milk or sugar, then it would no longer be safe to drink it after a day of sitting out.
Every good barista should consider one final point on the subject of mold: the importance of regularly cleaning your coffee machine.
The bacteria Pseudomonas is frequently found inside coffee makers, presenting a hazard to anyone who drinks its coffee, and also, this particular bacteria can degrade the caffeine properties over time.
How to store Brewed Coffee?
By now, you should understand the different stages that your coffee drink goes through. Let’s recap those quickly:
- Brew an amazing coffee
- Coffee begins to degrade after approximately 30 minutes
- Over time the coffee will continue to lose its flavor and taste bitter
- Bacteria and mold will start to grow, and the drink is no longer safe to consume
It’s possible that you accidentally made way too many drinks. To maximize the life and taste of your leftover coffee, here are three steps you can take.
Don’t Put Dairy In It!
Adding any milk or coffee creamer to your drink will significantly reduce your coffee’s shelf life as milk expires much quicker. If you plan to store your coffee, do not add milk or creamer until you are ready to drink it.
Use an Airtight Container.
Using an airtight container is cost-effective and straightforward to prolong your coffee’s life. I always keep my coffee beans in a sealed container for maximum freshness.
Doing the same with your cold brew coffee or cup of coffee will help preserve it for longer and avoid contamination from other smells and viruses in the air.
Put It In The Refrigerator
Storing your leftover coffee in the fridge may further reduce the oxidization processes, making the coffee more durable.
Remember to keep your coffee in an enclosed container, so it will not contaminate any other foods in its refrigerator or become contaminated by other foods such as onions.
While you can safely store your coffee for up to a week in the fridge, the taste will be slightly impaired, and really there’s no good reason to do so when even a small coffee machine can make 12 cups of fresh coffee in minutes, so there’s no need to make the same amount of coffee each day.
The only exception to this rule will be if you make cold brew concentrate. When stored in an airtight container, cold brew can be kept in the fridge for up to two weeks and still taste delicious.
Related Questions
Is it okay to drink coffee left out overnight?
Drinking coffee left out overnight is okay if it contains only black coffee and no milk or milk-based ingredients.
While drinking black coffee left out overnight is safe, the flavor will deteriorate after 30 minutes due to the coffee oxidizing.
How long is brewed coffee good for when it sits out?
Brewed coffee is good for up to thirty minutes when it sits out. After thirty minutes, the coffee taste degrades due to contact with oxygen.
Coffee will taste bad after about 4 hours when the oils in the coffee start to go bad.
This free cheat sheet will improve your coffee brew by providing quick information on brew ratio, grind size, optimal brewing time, and more.
