Slime in chiller water bath


I’m currently servicing our beer engines, and have discovered black slime in the water jackets which also blocked the silicon hose waterways.

On checking the chiller in the cellar, there are signs of a creamy coloured slime in the water as well. I assume it’s the same thing.

Before I reconnect the clean beer engines, I shall empty the chiller water bath and give it a good clean.

This is the only chiller affected, so I hope it’s a one-off, but are there any recommendations for an additive to the water, to prevent this kind of thing?

I seem to remember someone saying Milton fluid [basically bleach], but I think that this could have an adverse effect on the copper coils.

Any suggestions?


  1. Hi Querty, You would be surprised how often this happens in remote coolers. I wouldn’t recommend adding anything other than water to the water bath as it could compromise the stainless steel coils and affect the circulation pump. I have seen some baths absolutely clogged with slime. The point is this bacterial goo can form an affective insulation around the chilling coils and can cause fobbing problems with lagers and ciders. So like yourself if you know how to do it lift the lid and coils out of the bath and clean off any slime, otherwise give your tech services a call and get them to service your remote.

  2. Thanks for the info.

    I’ve already given the chiller a good clean and pressure washed it. There are no stainless coils in this one, just the copper pipes that carry the refrigerant.

    I believe that something like Milton or equivalent [which contains a small amount of bleach], would eventually turn the copper black and probably cause corrosion. Perhaps a very weak solution might be OK, but I’m inclined to leave it out for the time being, at least.

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