If you also reduce the temp of the beer in kegs, before you send it thru the Jockey box this will help maintain even temps. If you are wanting to cool a large volume constantly and quickly.
Stand kegs in water with a towel can help, or place kegs in a bin with water and ice.
I would be also checking all your other equipment. Jugs, spoons anything with threads and blind corners. Hose that you use, all of these things will contribute to your infection.
Here is the link to KL phosphoric acid
https://www.kegland.com.au/products/pure-phosphoric-acid-85-500ml
At the start of brew day I soak and pump the Phos Acid on all parts and vessels that I will use. Then I just start the day as per normal.
It is probably not needed but it kills germs from...
The phosphoric acid I have used is 96% and I bought it from KL, I believe they sell 85% now.
I personal didn't use the KK as it was one more part to wash, the Krausen scum line is easily cleaned when moist. I did not like to disturb the C02 blanket on the beer. Air after the start of...
Sad day and frustrating having to dump beer. I used the cooper fermenters for many years. Very easy to look after, 2 pieces and a tap.
I did change out the taps a few times as insurance.
I moved away from this type of fermenter for the pressure type as I went from bottling to corny kegs.
I recently put this style fermenter back into use after being in storage for 4 years. It has literally sat on the ground in a garden shed.
I put the tap parts in pre boiled water and treated as per fermenter.
I first poured boiling water on it. I then used oxiclean. I then used phosphoric acid...
If you are using the two-piece tap (Snap Cap) with the double Oring.
The Orings and the internals are an infection point.
The lever side has the rubber cover, pull the rubber back from the housing and inspect the internals. This is the biggest issue with these taps.
Transfer completed and no green apple for me.
So far it does taste different to my usual yeast choice, but not unfavorable. It will need to lager for a few days a will taste again.
My process at the end of boil is to add yeast nutrient.
I have used Lallemand life O yeast nutrient the last few...