Potential health problems from old coffee

Risks of old coffee Source: Unsplash.com

Coffee is a morning ritual for many, a comforting hot drink that helps you wake up and start your day. But what happens when your coffee is old? Can it affect your health? The answer may surprise you. Old coffee, especially if not stored properly, can cause several health problems.

Coffee that has been left for too long and has not been stored properly will of course deteriorate considerably in taste, but any milk can also spoil (very quickly!) and the coffee oils can become rancid. In addition, the antioxidants in old coffee can decrease, reducing coffee's health benefits . It is therefore advisable to consume coffee within a reasonable time after preparation and store excess coffee properly to avoid possible health problems.

Let's delve deeper into some of these potential health concerns of old coffee. But most of all, I would like to point out and advise you to only prepare the amount of coffee that you will actually drink within 30 minutes. This is much tastier, much safer for your health and less hassle.

Increased risk of bacterial growth

When coffee is not stored properly, it can lead to an increased risk of bacteria growth. In particular, old coffee that is not properly covered or stored airtight can become an ideal environment for bacteria to multiply.

Bacteria thrive in moist and warm conditions, and this also applies to old coffee. If coffee is not stored properly, moisture can enter the environment and promote the growth of bacteria. Additionally, exposure to air can cause bacteria to spread and multiply.

Consuming old coffee with high levels of bacteria can pose several health risks. Bacteria can cause food poisoning, resulting in symptoms such as nausea, vomiting, abdominal pain and diarrhea. People with weakened immune systems may be at even greater risk of complications from bacterial contamination.

To reduce the risk of bacteria growth in old coffee, it is important to store the coffee properly. This includes storing coffee in an airtight container in a cool, dry place, away from moisture and heat sources. It is also important not to store coffee for too long and to regularly check the expiration date .

Mold and mycotoxin formation in old coffee

Mold Source: Unsplash.com

If you leave black coffee at room temperature for a few days, mold can develop. Mycotoxins are fungi that can usually arise during the harvest and storage of coffee beans. Specialty Coffee is generally not affected by this because the coffee beans are stored correctly and mycotoxins therefore have no chance. If the coffee beans are contaminated with mycotoxins , this can have harmful effects on health.

Mycotoxins are not good for your health, especially if you ingest a lot of them. It can make you feel nauseous, give you a stomach ache, become dizzy and can even damage your liver if you are exposed to it for a long time.

To prevent mold and mycotoxins from developing in old coffee, you must ensure good hygiene. This applies during the harvest and storage of the coffee, but also certainly at home. Regularly clean and dry the coffee pot and other coffee equipment. Store your coffee beans in a cool and dry place, preferably in an airtight container. The bag of our coffee beans is a very suitable container, if you pack it airtight again after opening!

It is also wise to drink your coffee within a reasonable time and not to consume old coffee. By regularly making fresh coffee and avoiding old coffee, you reduce the risk of mold and mycotoxins.

Be aware of the potential dangers of mold and mycotoxins in old coffee. By practicing good hygiene and not drinking old coffee, you can enjoy a safe and tasty cup of coffee.

“Oxidation… This process causes a chemical reaction that causes the coffee to lose its freshness and flavor.”

Oxidation and Rancidity

Oxidation and rancidity are two common problems with old coffee that has been left to sit for too long. When coffee comes into contact with oxygen, oxidation occurs. This process causes a chemical reaction in which the coffee loses its freshness and flavor. The aromas and oils present in the coffee beans are affected, giving the coffee a stale and dull taste.

Rancidity is another consequence of prolonged exposure to oxygen. The fats in the coffee beans oxidize and become rancid. This results in an unpleasant odor and taste. The coffee can even get a bitter and spoiled taste.

To prevent oxidation and rancidity, it is important to use proper storage methods. Store the coffee in a cool, dry place, preferably in an airtight container. Avoid exposure to light and heat, as these factors accelerate the oxidation process.

In addition, it is wise to only grind coffee beans just before you start using them, because ground coffee oxidizes more quickly. It is also advisable to brew small amounts of coffee, so that you can always drink fresh coffee and do not have to throw away old coffee.

Understanding oxidation and rancidity is essential for coffee lovers to get the best quality and flavor from their coffee. By using proper storage and preparation methods, you can enjoy freshly brewed coffee without the unpleasant effects of oxidation and rancidity.

Possible negative effects on the digestive system and overall well-being

In this chapter we will discuss the possible negative effects of consuming stale coffee on the digestive system and overall well-being. Although coffee is often loved for its caffeine boost and delicious taste, drinking stale coffee can have some unwanted effects on our health. Let's look at the possible effects and how best to deal with old coffee.

Effects on the digestive system:

  1. Stomach complaints: Stale coffee can cause increased acidity, which can lead to stomach complaints such as heartburn, stomach pain and bloating. It is important to know how your body reacts to older coffee and, if necessary, take measures to reduce these discomforts.
  2. Disruption of intestinal flora: Regularly consuming old coffee can disrupt the balance of good bacteria in the intestines. This can lead to digestive problems, such as diarrhea or irregular bowel movements. It is important to strive for healthy intestinal flora by consuming fresh coffee and maintaining a balanced diet.

Effects on overall well-being:

  1. Reduced energy and alertness: Old coffee can lose its strength and therefore contain less caffeine. This can lead to reduced energy and alertness, making you feel less productive and less focused. It is important to choose fresh coffee to take full advantage of its energizing effects.
  2. Poor tasting experience: Old coffee can have a bitter and stale taste, which can negatively affect the overall coffee experience. Drinking fresh coffee provides a better taste experience and more enjoyment while drinking.


In conclusion, we can conclude that old coffee can have several unwanted effects on both our digestive system and our overall well-being. It can lead to stomach complaints, disruption of intestinal flora, reduced energy, and an unsatisfactory taste experience.

To minimize these possible negative effects, it is wise to consume fresh coffee and maintain a balanced diet. Let's not underestimate the value of fresh coffee and ensure better health and a more pleasant coffee experience.