Does coffee go bad overnight?

In this text, we will answer the question “does coffee go bad overnight?”. Also, we will explain the dangers of drinking reheated coffee. In addition, we are going to discuss the health benefits of moderate coffee consumption.

Does coffee go bad overnight?

Brewed coffee lasts 30 minutes at room temperature – so yes, coffee goes bad overnight. After 30 minutes the coffee is ready, its flavor is noticeably compromised.

Moderate consumption of coffee can be very good for your health. However, if coffee is consumed in excess, the excess of caffeine in the body, a substance present in the drink, can be harmful.

In the same way that it is recommended to grind the coffee beans when preparing them, prepare the drink with the right amount of powder and water, to extract the best from the beans, it is not recommended to reheat the coffee.

Although many people do this, this practice can be harmful to health in the short term.

Reheating causes the degradation of substances present in the coffee, responsible for the aroma and flavor of the beverage. In addition, the reheated coffee changes its original characteristics, leaving the drink with a bad taste, bitter in the mouth.

What happens to fresh coffee that is left out?

The coffee water can absorb aromas from the environment where it is to be left out for a long time, especially when this coffee is left in the refrigerator, where different types of aromas are found.

Coffee must be consumed within 20 minutes of its preparation. After that, the drink cools down and the drink’s oxidation process begins to occur, compromising its properties.

That’s why coffee tends to be much tastier in coffee shops. In addition to the coffee being freshly prepared and served, coffee shops often use freshly ground coffee beans and specialty coffee beans, which make a difference in their quality and in the complete flavor experience.

It is not recommended to heat the coffee in the microwave or on the fire, much less leave the kettle on top of the coffee maker’s “plate”. 

A very common thing is to store coffee for long hours in the thermos, this is not advisable. Although the drink is hot, its flavor will be affected, accelerating the drink’s oxidation process.

Even inside a tightly sealed thermos, the coffee should be completely oxidized within an hour. The reason this happens is because, at higher temperatures, coffee oxidizes faster. The beverage oxidizes twice as fast every 10°C above room temperature.

The best coffee is freshly prepared, using quality beans that are freshly ground, making the drink rich in flavor and aroma. Coffee beans must be stored in a well-sealed container to be away from air and insects, and the beverage must be brewed correctly. 

Furthermore, the coffee should be drunk as soon as the preparation is finished.

Why is fresh coffee good for your health?

Fresh coffee, freshly ground, is the best way to consume this drink and is good for your health. In addition to providing a complete and delicious experience of aroma and flavor, you can enjoy all the benefits it provides for your health, in addition to gaining that courage to face the routine.

Italian coffee makers and French presses are individually sized and both are some of the most popular and practical brewing methods to have around the house. 

We can also use the coffee machines in capsules – as they prepare different drinks, always made to order.

However, coffee consumption should be moderate, not exceeding four cups a day. Usually 3 to 4 cups of coffee a day show positive effects on the body. The cups should sum up to a maximum of 400 mg of caffeine/day.

Coffee also has potassium, zinc, iron, magnesium and several minerals in small amounts, in addition to caffeine, in its composition.

It also has amino acids, proteins, lipids, and small amounts of sugars and polysaccharides. In addition to all this, coffee has a huge amount of antioxidant polyphenols, called chlorogenic acids, which also help with weight loss.

In 2016, the World Health Organization – WHO – removed coffee from an extensive list of beverages that can cause cancer. In fact, some studies report that consumption of the grain can even inhibit tumors in the body, helping to prevent different types of disease, if consumed in moderation.

The bottom line

From what was described in the text, we can see that the coffee must be ground and prepared at the time of consumption, and that between 20 to 30 minutes after preparation, the process of degradation of substances that are responsible for the flavor and aroma characteristics of the drink begins.

In addition, freshly ground and brewed coffee has a better taste. The coffee that has been prepared and stored must remain in the teapot for a maximum of 1 hour.


In this text, we answered the question “does coffee go bad overnight?”. Also, we explained the dangers of drinking reheated coffee. In addition, we discussed the health benefits of moderate coffee consumption.


Hi, I am Charlotte, I love cooking and in my previous life, I was a chef. I bring some of my experience to the recipes on this hub and answer your food questions.