Why is the flavor of my coffee inconsistent?

by James
(Imperial Beach, CA)

QUESTION:

The coffee that I make in my drip coffee maker is very inconsistent in flavor. Sometimes it's wonderful, and others it is horribly bitter. I buy whole beans and grind them in a good burr grinder. I use one table spoon of grinds per cup. Could it be I just need a new coffee maker (it a Black and Decker, fairly cheap).

ANSWER:

That's quite a puzzle. If you use the same coffee, grind it at the same setting with your burr grinder and then use the same quantities of grinds and water each time you make coffee...there's no obvious reason why your coffee should be inconsistent in taste.

One thing you didn't mention is how long you leave the coffee in the carafe. I'm assuming your brewer has a glass carafe which sits on a hotplate to keep the coffee hot.

One thing is for sure. If you leave coffee on a hotplate for more than 30 minutes or so, it does start to take on a bitter flavour. Hence the popularity of thermal carafe coffee makers.

The only other thing I can think of is that your coffee maker might need descaling. If the water lines are being narrowed by a build up of scale, then it will take longer for the water to get through. This means that some of the water will be spending more time in contact with the coffee grinds before the full brewing process is complete – which can also lead to that slightly bitter taste. I can't see this making a huge difference, but it could make a small one.

If you do decide to get a new brewer, read our page on choosing the best coffee maker.