Grounds in coffee from filtering?


New member
Feb 8, 2005
Cortland, OH
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We've had grounds in our coffee once in a while and complained to our coffee supplier who provides our brewers. They've changed the baskets and just now installed a new brewer. They said out of 500 clients we are the only ones with grounds in the coffee and he blamed our reverse osmosis filtering system for providing too low of pressure when the reservoir tank gets low. He said we don't need to filter unless the water is really bad, which it isn't.

We've read that filtering the water is important and we wanted the best quality possible. We probably should upgrade our reservoir tank but we've been getting along by bypassing the filtering system when we notice the pressure dropping.

Is anyone else filtering their water?

Does anyone else get grounds in their airpots?

Could low pressure cause brewers to overflow?

One thought is that we may have the brewer setting setup for the lower pressure of the filter, and when we bypass then the pressure is too high for the brew basket to keep up. I'll start tracking when the problem occurs compared to the bypass status.


New member
Apr 17, 2005
Modesto, CA
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We've Had this Problem

and so did a family member of mine in the business too. the family member got them to grind the coffee a little differently and all was fine...either finer or less fine I don't know which way they went.

ours was fixed with a different "jet" sprayer or whatever you call it on the Brunn brewer. Underneath where the water comes out into the basket...once we changed this we eliminated the problem except on decaf....we still get grounds in our decaf which I use a tea filter to eliminate...


Active member
Aug 11, 2004
Des Moines, Iowa
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Hate to break it to you but RO water is only good for two things, and that’s to drink it or for tea. Coffee requires some dissolved minerals in the water to make a perfect cup. If you take them out you won't properly extract your coffee, which will leave with less than a perfect cup.

Here is how the SCAA defines a perfect cup.

RO is hard on espresso equipment, in the long run it will eat it up over time. Plus if you take your water all the way down to where there is no mineral content left anything that uses a fill probe won't work properly either. Water with no mineral content is not conductive. There for your fill probe system won't work.

On top of that how much water is your system throwing away to make 1 gallon of drinking water? A good system (not the cheap ones) tend to dump around 2 to 2.5 gallons of water to make 1 gallon of drinking water. The home units and a few oddball systems throw away between 3 to 4 gallons. I find that a bit excessive for water usage.

I'm not trying to be negative, I just wanted to make sure you had all the facts on RO! :grin: