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Coffee Tips

Why Does Microwaved Coffee Taste Bad?

You probably are familiar with this. You brew your cup of coffee, set it beside you as you fire up your laptop, and start working. Before you know, your cuppa is cold. You are too busy or lazy to brew another cup. Your quick and easy option is to stick it into your microwave and reheat it. One sip afterward, it tastes so bad. You expected the flavor to be the same but, it is the opposite. Why does your microwaved coffee taste so bad? How can you make your coffee taste better?

coffee in a microwave

Why Does Your Microwaved Coffee Taste Bad?

When you reheat your cold coffee, it will taste bitter. Here is why.

Unroasted green coffee beans contain acids that are bitter when heated up. Green unroasted beans contain chlorogenic acid that breaks down to quinic and caffeic acids during the roasting process.

The two acids produced also have a bitter taste. However, when you brew your coffee, the bitterness is balanced by sweetness in the coffee. This makes your coffee delicious.

When you reheat your cold coffee, the quinic and caffeic acids continue to break down and produce more bitterness. Here is why. You’re trying to extract more flavors from the coffee than you should. This explains why dark roast coffee is bitter compared to light and medium roast. Dark roast coffee takes more time and heat to roast the beans during the process.   It’s just like putting a baked cake back in the oven. The flavor and texture will automatically change.

When you microwave your coffee, you expect it to taste like the freshly brewed one, but the opposite happens.

How to Make Your Coffee Taste Better

You can brew a fresh cup of coffee or enjoy some iced coffee. It’s still delicious, especially during summer.

Still, do not leave your coffee in the carafe or any brewer to keep it warm. The brewers continue with the brewing process, and this will make your coffee bitter.

Instead, if you want to keep your coffee warm, you can use a thermal flask or insulated cup to insulate and maintain your coffee’s temperature.

Brew small amounts of coffee at a go especially, if you’re working from home. Give yourself some coffee breaks and take the time to brew some coffee for yourself. Through this, you will enjoy the rich in flavor and aroma cup of coffee that you want.

Reheat your coffee using a stovetop and at a low temperature. Low temperature will help retain some of the flavors in your coffee. Ensure you apply some patience here. This is how to reheat your coffee using a stovetop.

  1. Pour your coffee in a pot.
  2. Place the pot on a stovetop
  3. Lower the heat.
  4. Stir your coffee.
  5. Keep on checking your temperature.
  6. 135F is a safe temperature to avoid burns. However, the ideal temperature for coffee depends on you.
  7. Serve and enjoy your cup of coffee.

Preheat your thermal flask or insulated cup to maintain the high temperature. You can do this by pouring some hot water into the insulator then emptying the water. Do this before pouring your hot coffee into the insulating cup or thermal flask.

The decision to reheat your coffee depends on you. For some, the change in taste caused by microwaving coffee doesn’t affect them. For others, they don’t care about the taste. This all sums up your opinion.

If you still insist on microwaving your coffee, here is how to do it.

  1. Lower the heat in your microwave.
  2. Choose a microwave mug and fill your coffee. Leave some room in case the coffee boils. 1/4 space is enough.
  3. Cover your mug with a paper towel.
  4. Microwave your coffee for 30 seconds.
  5. Stir to find out whether it is at the temperature you want. If not, microwave it for 10 more seconds.
  6. Add flavor to your coffee if you don’t like the way it tastes. A cream will do the trick.
  7. Enjoy your coffee.


  1. If you’re using instant coffee or pour over method, bring your water to boil first. Leave it for 10 minutes then pour over your coffee. This will help you adjust your coffee’s temperature. However, most coffee in cafes is served at a temperature between 160-180F.
  2. While reheating your coffee, do not bring it to boil or heat it for too long. This will interfere with flavor and can cause burns
  3. Avoid reheating your cup of coffee if it has milk and creamers in it. This is because, milk easily spoils.