Biofilm in water reservoir - Page 2

Water analysis, treatment, and mineral recipes for optimum taste and equipment health.
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#11: Post by yakster »

Bleach will pit stainless steel, it's really quite harsh on materials so I'd probably stick with vinegar unless it's specifically called for. I have a water cooler that calls for a diluted bleach rinse as periodic maintenance.

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#12: Post by baldheadracing »

For future reference, you might be interested in this sterilizer for water reservoirs from Quick Mill. I'm linking just to show the idea - plenty of UV light sterilizers on Amazon, etc.
The video is 1:27 long

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#13: Post by Smo »

Vinegar causes protein coagulation, kills fungi and bacteria. But the protein becomes less soluble. Therefore mechanical cleaning is required.
Add vinegar to the raw egg white and see what happens.


#14: Post by Smo »

Silicone tubes come in different diameters.
Can be cleaned by inserting one into the other.
Alternatively, a blood transfusion system in a pharmacy.

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#15: Post by homeburrero »

I know very little about biofilms but this thread has got me interested and reading what I can find online. Fascinating subject!

elkayem wrote:I strictly use Crystal Geyser water from Weed, CA. After convincing myself this is safe, non-scaling water, I opted not to use the tank filter (though maybe I should rethink this).
I'm confident that's not the source of your biofilm - most likely it got into your machine and will stay and spread even if you were to use use perfectly sterilized water. The CG Weed water needs no softening and so you are wise to ditch the LeLit softening filter. It's of no help with soft water and may harbor biofilm flora.

The Weed water should be fine, but If you switch to something purer (water made from minerals, like R Pavlis water) take care to sanitize the containers you use to make and store the water and keep the made wqater in a cool dark place. I think I might avoid any recipe or water that includes calcium citrate (just because of citrate being a theoretical source of food for the biofilm).

To sanitize the reservoir with bleach I think you would want a stronger solution, around 1-2 cups of household bleach per gallon. Scrub the reservoir with detergent then give it 15 minutes or so of contact with the bleach solution, then let it air dry, then give it a final scrub and good rinse. The bleach solution would be corrosive to the metals in your machine. (per ... leach-use/ ) so you don't want to use that routinely through the machine. For the tubing I think I'd just replace them where feasible. And definitely toss out that resin filter.

Keep us informed. This is an interesting case.
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#16: Post by elkayem (original poster) »

Thanks for all the tips. I have cleaned out the reservoir, but given that this film coats the tube leading from the reservoir to the pump, I predict it won't be long before it returns. I haven't figured out exactly what I'll do yet, but leaning toward trying the vinegar option. The hard part is finding a day or two I can live without my morning espresso so I can do the cleaning.

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#17: Post by yakster »

That's one of the selling points of the Behmor BraZen brewer and the Robot espresso machine, no tubes for biofilm to accumulate, easy to clean. The use of filtered water which remove chlorine and chlorimides allows biofilm growth.

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#18: Post by PeetsFan »

This is the problem with using filtered water.
Municipal water treatment adds chlorine to water for a good reason! It kills bacteria. Filter the chlorine out, and now the bacteria can grow.

This happened to a Brita water pitcher I left on a countertop for a week. All I had to do was discard the filter and wash the pitcher in a dishwasher, but it was a valuable lesson.

One way to destroy the growth internally may be to clean your reservoir, then run unfiltered tap water in the machine for a week or two. The chlorine will so its work.