Hi everyone,
Just thought I'd share my experience using a plastic Still Spirits Z Filter that I got as part of a kit (second hand admittedly). All the bits seemed to be included, fittings, washers, mesh etc. so I filled up the 3 columns using CB branded carbon, leaving about 10mm gap at the top of each column. Then I flushed it with water for about a minute. I cut out a double layer of coffee filter paper and put it in at the output end of the filter and the wire mesh at the input end. The hose was connected to the tap on a bucket containing 6 litres of 40% neutral.
The first few drops came out quickly - though it was mostly residual water from washing out the column. The next 200 ml of spirit came through at a steady trickle... And then the thing seemed to stop, taking about 3 hours to filter roughly 500ml of product. Fearing that the double filter paper was too thick, I pulled apart the bottom of the column and took out some paper. I probably shouldn't have touched it. Both of the top caps then began to leak and more spirit was coming out of the seals than out the tube at the bottom. Thinking there might be too much pressure on the caps, I then pulled out the remaining filter paper and swapped it with the wire mesh. It sure sped up the filtration, but it was now gushing out the end now. And my precious neutral was now a nice shade of cloudy grey.
This is where I reckon I went wrong:
I should have washed the carbon better. Apparently the mineral salts in the unwashed carbon will come out and make your product cloudy.
Impatience and not knowing how slow the filtration would be made me panic. Apparently this process can take up to 24 hours depending on your volume. I should have just let it go and do its thing.
Filtering it in the first place. Maybe the whole lot should have just gone through for a second distillation rather than a carbon filtration.
Happy stilling, hope this post helps someone!