Last Updated on June 27, 2023 by Barry Gray
Have you ever gone ahead and brewed a bit too much coffee at the one time? Having some coffee sitting there in the pot just waiting for you to drink is something I think most people have done at some point.
But it has led me to think about something I feel is important.
Just how long will that pot of coffee stay fresh?
I recommend drinking it within 30 minutes of brewing. Around the 30-minute mark, coffee will begin to oxidize, impacting the taste and your overall experience. It can turn a tasty coffee bean into one you would rather just throw away, so it doesn’t stay fresh for as long as most people expect.
I know I was surprised when I found this out. I’ve left coffee in a pot for substantially longer than that before returning to reheat it.
Honestly, I think after what I discovered during my research that I will be looking at that pot of coffee in a different light from now on.
Is it Safe to Drink Coffee Brewed Hours Ago?
I will go into what’s happening with your coffee later, but let me deal with any worries you have about drinking that coffee brewed a couple of hours ago.
I know almost every single individual reading this has probably had some coffee that they know was brewed at least an hour earlier. Some may have pushed this time out to several hours.
But here’s an important point.
Coffee that was brewed several hours earlier is still safe to drink. It won’t make you ill.
Actually, the only problem you may encounter is that it just won’t taste that good. However, at least it won’t give you food poisoning or anything like that.
Basically, don’t worry. So many people have consumed old coffee that we would have heard it was bad for us before now.
How Long Does Coffee Stay Fresh?
Now, there’s a whole debate about how long it’s safe to keep coffee in the pot, but that’s a different discussion from how long your coffee will stay fresh. So, I will focus on the question of freshness first.
This is where that 30-minute mark comes into play. However, I do know some people feel that even 30 minutes is too long.
For them, 20 minutes is long enough before coffee starts losing some freshness.
Honestly, it comes down to personal taste and preference here. I’ve tried coffee that I’ve left for 20 minutes, 30 minutes, and 40 minutes with minimal differences in taste.
But I get it. You might hate the taste of coffee after 30 minutes but remember it’s still completely safe to drink.
What Happens to Coffee After Brewing?
I was intrigued about what happens to coffee once you begin brewing. Why does it start to experience a change in flavor in under an hour?
It’s all down to a chemical change that occurs when you brew coffee, and there’s not much you can do to stop it.
The problem is with oxygen. When you brew coffee, it’s exposed to oxygen, and the two things are not best buddies.
What happens is that solubles contained within the coffee start to oxidize when exposed to oxygen. This, in turn, leads to a degradation of the coffee, and it tends to focus on two key areas: taste and aroma.
Now, I know both taste and aroma are kind of important things when it comes to coffee. Still, I do notice one particular thing when coffee is left alone for some time after brewing: it becomes stale.
But then, the idea of coffee going stale like this is not a surprise. During the chemical reaction of those solubles oxidizing, one thing happens to the coffee: the pH rises slightly.
I am talking about the pH only changing slightly, but it’s enough to make a difference to the taste of the coffee. It takes on more of a bitter taste when left alone for some time, and you will notice the difference even if you love bitter coffee.
And yet, here’s another interesting thing I discovered. The heat of the coffee changes how long it will stay fresh.
The reason for that difference is simple. This oxidization process is slowed when the temperature of the coffee is cooler. It needs heat to really get the process moving along, so colder-brewed coffee should end up tasting the same for an extended period.
But then, not everyone likes the idea of cold-brewed coffee, and I cannot blame them for that. It’s not a personal favorite of mine either.
What Does the Coffee Taste Like?
The coffee’s taste will vary depending on the beans used, but that’s not what I’m talking about here. After all, that’s a very long discussion all on its own.
Instead, I’m talking about my own experience of tasting coffee that has been left in a pot for some time.
What I found was a gradual decline in the quality of the coffee. I admit I had to make quite a large pot and then only take a small drop at a time to experience the coffee as time progressed.
However, it was still enough for me to draw some conclusions.
After 30 Minutes
After brewing, I sampled the coffee and waited 30 minutes to see the difference. Seriously, I didn’t get anything too different.
If there was a change in the taste, it was very subtle, but it still came across as pretty much the same cup of coffee as what I’d experienced at the outset.
After 45 Minutes
By the 45-minute mark, I felt the aroma was not quite as it was before. It was almost as if the aroma had been diluted.
Now, you experience coffee by using more than just your sense of taste, so I was more apprehensive when it came to tasting the coffee.
It turned out that I was quite right to feel this way.
It became clear in almost the first sip that something had changed with the coffee. The taste was different because the coffee had a slightly more tart flavor.
This was not something I had really encountered before. I know the coffee had a bitter taste to it from the outset, but this was different.
After 60 Minutes
By 60 minutes, the coffee had just followed that downward trajectory I had started experiencing at 45 minutes.
My experience was the aroma had really died, and so had the taste.
I do love quite bitter coffee, but it’s almost as if my brain remembered what the coffee tasted like just an hour earlier, and it couldn’t make sense of what it was now encountering.
It was not the worst coffee I’d ever tasted. However, the difference I experienced was something that was very prominent.
I know you would experience the exact same thing if you conducted this experiment.
What Happens if You Keep the Pot Warm?
Filter coffee may come with the option for the pot of coffee to be kept warm, and people think this will help maintain the coffee’s taste for longer. Well, it’s a nice theory, but it does not work.
Instead, you are increasing the chances of turning a decent cup of coffee into one that tastes horrible. I will explain why that’s the case.
The first thing to consider is the point regarding oxygen and oxidization and how heat plays a role. So, keeping the pot warm will only serve to increase the oxidization, and that’s not something you want to happen.
Also, I find coffee ends up tasting as if you have managed to burn it when you keep the pot warm. That’s not a taste you want to experience, so I would prefer to let it cool naturally and then reheat it when I’m ready to drink it.
Won’t Coffee Taste Stronger if Left to Stand?
People make the mistake of thinking that coffee left to stand will actually taste stronger. Well, that’s not the case.
This is something that is impossible. The strength of the coffee comes from the water coming into contact with the ground coffee.
But when you have made the coffee, that interaction between water and ground coffee can no longer exist. After all, the ground coffee is not there.
Yet I know some people still swear by the coffee tasting stronger after it has been left in the pot for some time. So, let me explain this to you.
What is actually going on is the coffee is becoming more bitter as it stands. It’s because of that oxidization process I’ve mentioned several times.
This change in the taste of coffee is the one thing that is then giving the impression that the coffee is stronger. But the reality is that this is not the case.
Can You Store Brewed Coffee for Hours?
If you intend to keep coffee for longer, then you could store brewed coffee for 24 hours. However, you need to use the fridge to achieve this.
Storing coffee in the fridge is the best option. However, do allow the coffee to cool on its own before you put it in the fridge.
Also, keep it in a sealed container. A flask is perfect. Although you could keep it in the pot, but that stops you from using the pot the following morning, so it’s hardly the ideal solution.
But the main point is it’s completely safe to do this, even if the coffee won’t taste the same.
My Recap on How Long Coffee Will Stay Fresh in the Pot
Several key points stand out regarding how long coffee can stay fresh in the pot.
- It’s safe to drink coffee hours after it has been made
- The aroma does degrade as time passes
- The taste degrades as time passes
- Around 30 minutes is prime time before coffee begins to taste stale
- It will become more bitter as time progresses
- Your coffee will not taste stronger the longer you leave it
- You can store it in the fridge, as it will help preserve some of the taste
Overall, I would only make enough coffee that I know will be polished off within 60 minutes. Even pushing it to 60 minutes will not always work out too well.
But then, it also depends on your own personal preference regarding the taste. If you love the taste of bitter coffee, then it may not be too bad.
If you plan on brewing a big pot of coffee, I suggest you drink it within 30 minutes to still have the chance to savor the full-on taste. However, I also feel up to 45 minutes will also mean the coffee tastes pretty good.
But don’t worry if it does go past that time. It’s still safe even though your experience won’t be the same due to the difference in taste.