Why Is My Coffee Machine Making Weak Coffee?

When it comes to getting your coffee just the way you like it, there’s nothing more convenient than a coffee machine at your home. It’s easy, it’s cheap, and it doesn’t require standing in a line every morning. However, what can you do if your machine suddenly starts making coffee that’s too weak for your taste? Step one is figuring out why.

Your coffee machine is making weak coffee because the coffee grounds have lost their intensity, or the brewing method isn’t extracting enough essence. This can happen if you’ve not stored the coffee grounds properly or the water supply is too cold for the coffee machine.

The above broadly covers the reasons your coffee machine is making weak coffee. In this article, you’ll learn more specifically what different factors might contribute to weaker caffeine content or poor extraction alongside different solutions to each possible issue.

Weak Coffee Grounds

Weaker coffee is more often the result of poor grounds than a poor machine. That’s why it is likely that your coffee grounds were exposed to humidity or weren’t stored well, which resulted in premature oxidation. To make sure that this was indeed the cause, you must ask yourself what you changed more recently. 

If your coffee machine was fine before you got a new batch of coffee grounds, then the problem is in the grounds. However, more often than not, people don’t attribute any problem to the grounds because they think that the grounds are the same as before. You may get the same brand, roast, and coarseness yet have weaker coffee if the coffee grounds are exposed to the environment.

To preserve grounds, you must store them in an opaque container like Veken Coffee Canister. This blocks the sunlight from affecting the coffee grounds. More importantly, you must make sure the grounds are stored in a dry environment as any exposure to humidity will destabilize the caffeine content, which might start getting released into the environment. 

Airtight containers and jam-packing your ground container, so there’s no room for air in it, are two ways to ensure that your coffee grounds are stored well.

Of course, there’s also the possibility of the problem not being with grounds. Still, being cautious and making sure your coffee grounds have the same density of coffee essence as intended by the producer helps offset the weakness of your coffee machine to some extent.

Poor Brewing Technique

It is also possible that the coffee grounds have just the right amount (and density) of coffee essence, but the brewing method is not able to extract the required content. Since there are two main factors in a brewing process that affect the caffeine and flavor output of coffee, let’s look at each possibility. 

The first is simply that you’re not using enough grounds. This can happen when you go from making coffee for a group of people to making it for one individual. Adjusting grounds or instant coffee in a coffee maker can be prone to miscalculations, and the easiest way to check if this truly is the cause of weaker brew is to simply load your coffee machine with more grounds and taste the result.

The second part of the brewing process is how long the coffee is brewed. If you’re switching from one method of brewing to another, you might retain the brewing time of the previous method. This is one of the most common reasons for coffee not coming out as strong as it should. 

An almost absurd example of this would be to use the french press brewing time in a cold brew. Since cold brew is processed at a very low temperature, you have to brew it for a whole day. French press, on the other hand, is hot enough not to require even half an hour to brew. 

Moving from a high-temperature brewing method to a lower temperature one might not always be as drastic as going from a french press to a cold brew. Still, it is worth brewing your cup a little longer just to see if the time increase results in a better cup.

Water Supply Too Cold

As covered above, the brewing time is linked to the temperature of the water in which the grounds sit. Most smart appliances automatically adjust for this by having thermostats that heat the water to a certain degree. This means the temperature of the water coming through the inlet is irrelevant as the heated result will be uniform.

However, if your machine isn’t temperature-sensitive and has a heating timer that assumes room temperature, then the water gets heated for the amount of time required to heat water that comes out of the faucet. And if the water that goes into the machine is colder, it will not get heated as much before the timer runs out.

To make sure that this is indeed the result of your coffee machine’s timer and resulting temperature, microwave a cup of water before pouring it in or connect the machine to an inlet with warmer water. If the resulting brew is stronger, you’ll have detected the problem and tested the solution.

Problems With the Coffee Grounds

Finally, there’s also the very real possibility that the coffee grounds are too coarse for the brewing method. Remember, what you consider “weak” coffee might be someone else’s “ideal” cup. People pick different roasts and grinding tiers to ensure a specific amount of essence in the resulting cup. 

The brewing method or the ground tier can be adjusted to get a stronger or weaker cup. If your machine serves the coffee it serves, you can make the cup more powerful by going for a finer grind. Put simply, the surface area of the bean increases with finer grinding, which makes sure that with all things kept the same, there’s more coffee essence in the resulting cup.

Then there’s also the option to get your coffee lightly roasted. Yes, a lighter roast will result in stronger coffee. Since we associate “dark” with “bitter,” it is easy to assume that darker roast equates to stronger coffee. Darker coffee loses a lot of its essence during the roasting process. Try a lighter roast and see if the resulting cup is up to your preference for strength.

Final Thoughts

Your coffee machine might be making weak coffee because of a few factors that have to do with the coffee beans, grounds, and water. These are discussed above and recapped below.

  • The coffee beans have environmental damage.
  • The grounds are too thick or heavily roasted
  • The water is too cold or not heated long enough

Tim S.

Tim loves roasting, brewing, and experimenting with coffee. After years of perfecting this craft, working as a barista, and owning a small coffee service in college, he has decided to share his knowledge with the world.

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