Is It Safe To Drink Leftover Coffee Left For A Long Time? This Is Expert Explanation

Coffee Illustration (Adrianna Calvo / Pexels)

JAKARTA - Coffee is the favorite drink of many people in the world, even coffee is often chosen as a drink to fill leisure time or be used as 'friends' when completing work.

Coffee can be served either warm or cold. But unfortunately in consuming it, many people are accustomed to not immediately finishing coffee.

Some people often leave the coffee cup on the table without finishing it immediately. It may also happen to those who enjoy coffee while talking or finishing work. From a health standpoint, is it safe?

Reported by Eat This, Not That !, Wednesday, February 3, drinking back coffee that has been on the table and is open for hours is not a cause for concern. However, this only applies to certain types of coffee.

From a microbial point of view, leftover coffee is relatively safe to drink again. But only pure black coffee without a mixture of sugar and milk like a glass of Espresso or Americano.

Even so, coffee can be overgrown with mildew or its derivatives. According to food researcher Bryan Quoc Le, PhD, this can affect a small number of individuals who do have an allergy sensitivity to mold.

When you leave coffee in the pot all day long, it's best to stop drinking it. Le noted it took several days for the coffee to grow mold.

Unlike black coffee, coffee with a mixture of sugar or milk is highly recommended for immediate consumption. In accordance with the CDC food safety guidelines, coffee with milk has a maximum time of 2 hours for consumption, after being served at room temperature.

Experts also don't recommend drinking leftover coffee again because the taste might change. One of the problems in coffee is that it is susceptible to oxidation and results in loss of aroma and changes in taste in coffee.

"The biggest problem with coffee residue is the taste. The taste, aroma, and oil molecules in coffee are susceptible to oxidation, wherein the oxygen in the air reacts with these compounds and forms plastic byproducts that affect the taste," says Dr. Le.

Not even certified barista Yurii Brown would recommend saving leftover coffee and enjoying it again. Even if the rest of the coffee is stored in the refrigerator.

"Maybe it will absorb odors from the kitchen or food in the refrigerator. As a result the coffee will taste and smell like a refrigerator," said Brown.

In addition, leftover coffee left for quite a long time also affects the health benefits it contains. The beneficial content in coffee turns out to be not effective when it has been exposed to air for a while.

"Ingredients such as antioxidants can protect against aging and many diseases can decrease over time due to oxidative stress," Brown continued.

But if you don't want the hassle of brewing coffee multiple times, there are easy ways to solve it. You can brew more coffee for 3 to 4 cups and then store it in the refrigerator.

Only serve enough to fill a cup without removing the large container at room temperature. Coffee that is always kept in the refrigerator is more likely to keep for 2 to 3 days.

"Storing coffee in cold temperatures allows to stop the growth of any bacteria and remains safe to store for several days," concluded Brown.