Does Coffee Get Stronger the Longer It Sits?


Do you hate strong, bitter coffee and want to know if letting your drink sit out will make it more bitter? Or, maybe you love bitter coffee and want to make it more bitter by leaving it to sit longer. Either way, we have the answers for you.

The longer ground coffee is allowed to sit, the stronger and more bitter it will become. Coffee will typically start to become bitter after about 30 minutes of sitting out. This is because the coffee grounds and the water pulling the solubles from the ground, oxidizing the coffee.

Want to know specifically why this happens and how to stop this from happening? Keep reading! We have the information you need about your coffee!

Why Does This Happen?

If you made some fresh coffee, and the coffee grounds are still in the cup or the coffee pitcher, the coffee in fact WILL get stronger and more bitter. Wondering why this is? Well, keep reading!

Business Insider tells us why this happens. They say “But as the boiling water pulls out the solubles from the grounds, they continue to oxidize yet again, giving hot coffee more of a sour and bitter taste. This process begins to happen the moment any water hits the beans, and it gets more intense the longer the coffee sits after you brew it.” This explains why coffee gets more bitter when it sits to brew.

When it comes to the temperature of the room, this can help make or break the coffee staying better for longer. Coffee that is left out in extreme heat or cold won’t taste as good to drink, which is why room temperatures are best for coffee.

How to Stop It from Happening?

Do you dislike bitter coffee and want to know how to stop this from happening? Here are some dos and don’ts for you!

Drink It All

If you don’t want your coffee to become bitter, consider drinking all of it! This is the best way to ensure that your coffee will not get bitter. Make sure to drink it within around 30 minutes. Coffee that has been sitting for longer than 30 minutes will start to go bad and the flavor will begin to change.

Avoid Putting It in Fridge or Freezer

If you are wondering if you can put coffee in the fridge or freezer to make it stay better for longer, doing so won’t help. Putting your coffee in the fridge or freezer to try to make it less bitter and give it a longer life span, will not help the coffee at all.

It may seem like it will keep it better for longer, but it will not. If you want your coffee to stay cool, go ahead and put it in the fridge, but don’t leave it in there for too long. It most likely won’t help much, except for keeping the coffee colder for longer periods of time.

Add Sugar or Cream to the Coffee

There is a super quick and easy solution to coffee that has been sitting out for too long and has become bitter, and that solution is to add sugar and/or cream. Adding sugar or cream to your coffee will make it less bitter. If you let it sit out for a while and it becomes too strong and bitter, consider adding some cream or sugar to help decrease the intense taste of the coffee.

What About Coffee without Grounds?

What about coffee that sits out without coffee grounds? Well, this coffee most likely will not get stronger or bitter. This is because the coffee beans aren’t there to intensify the flavors. There is a chance that the flavor will begin to decrease if it is left out too long. If you put cream and sugar in the coffee and it sits out without grounds, then the sugar and cream may decrease in potency, so the coffee might become stronger and more bitter.

Will Adding Milk Make It Last Longer?

If you are curious if putting milk in your coffee will help it stay better and less bitter for a longer amount of time, we are here to tell you that it will not.

It may help to add cream to your coffee and make it less bitter for the first bit of time while drinking it, but as milk sits in coffee, it begins to go bad. The milk will begin to curdle and rot as it sits in your hot coffee. This is why you should drink the coffee instead of letting it sit out, as you never want to drink a cup of coffee that has curdled milk in it.

How Long Can Coffee Technically Sit Out?

Coffee can sit out however long you want without it going “bad” unless it has milk or cream. If you don’t like bitter, strong coffee, I wouldn’t leave it out for longer than 30 minutes to 1 hour. I’ve seen people leave it out for hours and still drink it, so it all just depends on how you like your coffee.

If it doesn’t have milk or cream and you like it bitter and strong, leave it out for hours if you wish. It technically is still okay to drink, but we will touch on that a bit more in the paragraph below.

Is Left Out Coffee Bad For You?

As mentioned above, left-out coffee can be bad if the milk or cream is sitting in the left-out coffee for too long. This is because it begins to curdle in the hot coffee. Now, you may be wondering if there is anything else you should worry about when drinking left-out coffee, and luckily for you, there is not. It is safe to drink left-out coffee unless it has milk or cream in it. It probably will not taste as good, but it is 100% safe.

Does Left Out Coffee Taste Bad?

Whether or not coffee that you left out for a few hours tastes bad depends on your taste in coffee! If you like bitter coffee, you may like it! If you don’t like bitter, strong coffee, you may dislike the taste of it. Just be watchful of any coffee you make and don’t let it sit out for too long if you don’t like the taste of bitter coffee or coffee that loses its flavor.

Good luck and happy coffee drinking!

Charlie McFarlane

Specialty Coffee Enthusiast. Hungry for knowledge in the art and science behind specialty coffee and decided to document my journey, sharing it with the public. +10 baristas interviewed. +20 farms toured across 5 countries. +75 Coffee Shops throughout 10 countries.

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