After months of use, the metal filter used in my French press coffeemaker now has small traces of coffee grounds stuck between the mesh fibers which cannot be removed by brushing either side. Seeing the advice in How do I effectively clean a metal Chemex filter?, soaked the filter in 5% vinegar for multiple nights, but unfortunately the grounds remained embedded in the mesh.

Before trying alternative methods in the linked post, I wanted to check with folks here to see if any were particularly effective, especially before applying any of them method to clean a metal, cylindrical cold brew filter, which would be more difficult to replace if damaged than the metal mesh of a French press:

  1. Soak filter in vinegar (acetic acid) solution
    • The recommendation seems to use a solution of 1 part vinegar, 1 part water. Any drawbacks to using pure vinegar (which itself has low acidity, 5% in my case)?
  2. Soak filter in lemon juice (citric acid) solution
  3. Soak in bleach
    • Any concerns about damaging filter?
  4. Soak filter in baking soda
    • Any advantage to combining baking soda with vinegar for the soaking solution?
  5. Boil filter in water
    • For cleaning a cold brew metal filter which is not designed to withstand temperatures that high, any concerns about the metal deforming or joints coming loose?
  6. Boil filter in vinegar
  7. Boil filter in water with teaspoon of Urnex coffee equipment cleaning powder
  8. Massage soap through filter
  9. Use an ultrasonic cleaner
  10. Use a high-pressure water stream, such as from a Waterpik, to force the coffee grounds out of filter holes
  • 2
    "Any advantage to combining baking soda with vinegar?" — The fizzing makes it look like it's doing something, and it's slightly possible that the mechanical action of the bubbles might dislodge something. But otherwise, combining vinegar and baking soda is less than useless as far as cleaning is concerned (in general, not only for this case). The acid and the base combine chemically and neutralize each other resulting in a very weak solution of whichever one there was too much of, plus sodium acetate. Apr 24, 2023 at 13:34

4 Answers 4


I'm not a chemist, but I'm confident that you won't be able to dissolve coffee dust using conventional cleaning methods. I think the chemical solutions you describe are primarily aimed at dissolving oily residue.

If fine grounds are stuck in the filter, I'd try to remove them mechanically. In this case, I think air pressure from a compressor could push them out.


It is possible to completely dissolve coffee grounds while cleaning a metal filter?

It is not necessary, Take it apart and clean it if you need to.

Just unscrew the filters from the stem and separate everything so you can clear all of the old grounds out. Put it back together the SAME WAY it was.

I found this video on how to clean a french press.

(note: I do not like the Starbucks roast, it was just the best video I could find)

I only rinse mine while tapping on the side of the sink, daily, and only take it apart once in a great while. I do not have bunch of grinds that get in and are not able to be dislodged and I don't care if few are left in the filter. Is your grind coarse enough?

  • 1
    Definitely a good point. For the French press, I had indeed disassembled the press and isolated the mesh filter before trying the vinegar soak. And you're spot-on with the grind observation, for in laziness the grind used here is on the finer side.
    – mxxk
    Dec 9, 2020 at 0:14

Caustic cleaners such as PBW, along with hot water help to break down organic compounds (oils, coffee dust, etc). Baking soda works in the same manner, but you may need a heavier duty cleaner.


Soak well in vinegar or acetic acid and then poke at it with a fine brass wire brush having separated the wires a bit. Mine is completely clean now using this.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.