Why are filter baskets hard to clean?

in Brewing Coffee, Coffee Maintenance

Question: “Why do manufacturers put ribs inside the filter baskets? This makes them very hard to clean.” – Ron Varley

Answer: Excellent question, Ron.  Who doesn’t hate trying to clean between the ribs of a drip brewer filter basket. As we go over in the site’s section on Coffee Maintenance, you want to make sure you’ve cleaned all residue from everything that coffee touches.  Coffee is oily and attaches itself to whatever it is left on.  It is also perishable, so that even the residue will go stale in time and affect the flavor of coffee you make later on.

So why the ribs on the inside of the filter baskets?  To figure it out, I found myself looking at all kinds of design patents for filter baskets and then the answer jumped off the page.  It’s not the ribs that are important, but the space between them.  As hot water passes through the coffee and filter, it needs to flow to the center of the basket to drip out into the pot.

If you used a paper filter and those ribs were not built into the basket, then it would take the coffee longer to “canal” its way to the center of the basket and drip through.  Instead, the space between ribs is the area where brewed coffee travels from the filter through to the drip-hole, and into the pot. I’m not an engineer and sometimes lousy at explaining these types of things, so I hope that makes sense.

My advice on cleaning it is to rinse it as soon as possible right after the coffee is brewed.  That way, none of the residue will set.  Otherwise, a dish-cleaning sponge will get into ribs to clean them out better than a cloth. A dish brush is best of all. I confess that since I use a mesh filter instead of paper filters that I don’t clean the filter basket as often as I should.  So it is probably collecting residue from the previous pots I’ve brewed and leaving me with less than optimal coffee flavor.  Something to remember, so thanks again for the question.


  1. My question is how do you remove coffee stains from the plastic filter cup that you pour your coffee into. The plastic is permanently stained dark brown and bleach, cleanser, etc. don’t work. I also can’t find a replacement filter/cup for my coffee pot. Very frustrating.

    Comment by Margaret Buzzanca — January 16, 2016 @ 5:29 pm

  2. I don’t know if it can be cleaned short of replacement. The good news is that it shouldn’t be imparting flavor into your coffee. However if you are finding that’s not the case, the manufacturer should have a spare parts list from which you can order a replacement. It sounds like you’ve tried that though. If you do find a replacement, the occasional (monthly) vinegar/water cycle through your drip brewer will provide a gentle but regular cleaning.

    Comment by Marc Wortman — January 17, 2016 @ 6:36 pm

  3. I followed directions on bottle of”CLR” today. Drip basket is stained darkly and seems to smell of stale coffee. I’m not sure what would help neutralize smells. (I use baking soda and vinegar too, maybe 2-3 times a week.) Any ideas?


    Comment by Jane — November 30, 2017 @ 10:34 pm

  4. Jane, I hate to say it, but I wonder if you should replace the basket. The vinegar rinse should’ve done the job and CLR most definitely should clean the surface. Your brewer should have come with a list of replacement parts.

    Comment by Marc Wortman — December 5, 2017 @ 2:12 am

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