StillSmart

I was just thinking about filtering.......
I usually distill the spirit twice then filter it maybe 2-4 times before drinking.

I have read posts about distilling then filtering straight away and repeating distill then filter.
Any comments about either process?

Anyone tired both?

Do you think it would matter either way?
The only single disadvantage of distill>filter i can think of is maybe the carbon will used faster with the spirit getting filtered earlier?
Anyhow......comments anyone???

I thought that too, the carbon would expire quicker. Plus the time required to filter it. They say you should not reuse the carbon more than once, I do and not had a problem though.

They say a lot of things
I have heard its best to: chill before filtering, use carbon once, don\'t let any air in filter between batches, filter at low (40%) alch.

all of which I have tried and IMO have found makes little to no difference.
re: the carbon use I go by smell, after the spirit if filtered if it smells filter again or change the carbon. If it smells good then your cabon is fine

I only filter once and use the carbon once but I use the Z filter with a difference I slow it down with a piece of wet cotton wool in a bit of siphon tube at the end which forces all the liquid to sit on the carbon for hours, my last lot was about 8 litres and took just under 40 hours to filter but as it’s a set it up and forget it, its not a problem.
If you re-use carbon I think I read that it’s a good idea to soak in boiling water or even boil it for a bit to clean it up.

As far as I understand it (courtesy of Gert Strands free ebook) is that the more you use a batch of carbon, the further down it the impurities go i.e. if you have one of his home made filter designs, say a pipe of 3ft long, pinched off to reduce the flow to a minimum, then initially the impurities will all stay in the top 6 inches of carbon after the first run.
If you then use the same carbon again, the contaminated area moves down further, for example from 6 to 12 inches in the batch of carbon, etc etc.
Though he does point out that if you then rinse the carbon in boiling water 4 or 5 times it\'s fine to re-use (I then dry mine out in the oven on a baking tray). The filtering ability of the carbon after rinsing like that is restored to about 80% from new, then you only have to replace small amounts where some of the particles have broken up during the washing process.
I can see value in using bluecaps idea about limiting the flow through the carbon, though I\'m not so sure that it needs to be that slow, but there must be an optimum flow rate through the carbon to remove as many impurities as it\'s capable of - I wonder if it\'s written down somewhere......Damn, now where did I put that print off of GS\'s carbon book ??

DO NOT DRY OUT USED CARBON IN THE OVEN IF YOU HAVE A GAS COOKER! Not unless you want to be picking pieces of it out of your forehead. Electric is supposed to be OK, but to be honest it\'s cheap enough not to bother in my opinion.
My view on carbon is that it is for polishing off the spirit when you\'ve finished distilling - that\'s not to say that it\'s the only way of doing things, but to my mind it is no substitute for a quality fermentation and careful distillation. It just cleans things up at the end, but doing it more often shouldn\'t hurt (when making a neutral spirit of course).

DO NOT DRY OUT USED CARBON IN THE OVEN IF YOU HAVE A GAS COOKER! Not unless you want to be picking pieces of it out of your forehead

Why not ? I\'d rinsed mine through with boiling water about 5 or 6 times. Then spread it out thinly on a baking sheet and put the oven on a very low gas just to basically drive the water out of the carbon.
It worked a treat.
So what is the likely explosion hazard ?

In theory, there will still be alcohol suspended in the pores - if you\'ve done all you said then it\'s very unlikely to have any effect, but I didn\'t want anyone mis-reading it and just chucking some in the oven, you never know! Perhaps me just being over-cautious, I just don\'t like the thought of someone coming a cropper because of something they read on a site I\'m supposed to look after! I don\'t mean to imply that you don\'t know what you\'re doing Phantom, sorry if I seem picky!

Da nada Jimmy.
The whole point of rinsing it 5 or 6 times is to remove as much of the absorbed impurities as possible - I just spread it out and dried it in the oven as I didn\'t want to have a tray of black sludgey pellet hanging around to dry.
One of our cats would have probably tried to crap in it!
The lowest oven setting dried it out in about 2 hours just nicely - but I think that you\'re right to mention the potential hazard of not rinsing the carbon enough....

I\'ve been thinking about this carbon filtering thing, if the object is to bring the spirit into as much suface contact as posible. Why can\'t we just bung a quantity of carbon into the spirit, agitate it for a few days and then filter it of?

Theres probably a good reason why you can\'t but I just wondered if it was a viable experiment.
Opus

The section in \"Gert\'s\" ebook points out that, say you run a batch down a \"straight pipe\" type filter (metre long for example), then the impurities will stay in the top X amount of carbon. The next batch increases the amount of impurities held in the carbon and the \"impurity margin\" moves down the carbon, etc etc until the carbon can\'t hold any more.
That\'s when I use Gerts suggestion about rinsing the carbon pellets in boiling water half a dozen or so times and then final rinse and dry out.....

I\'ve been thinking about this carbon filtering thing, if the object is to bring the spirit into as much suface contact as posible. Why can\'t we just bung a quantity of carbon into the spirit, agitate it for a few days and then filter it of?

Theres probably a good reason why you can\'t but I just wondered if it was a viable experiment.

Opus
I\'ve tried it without much success, i think you\'d need to put a lot of carbon in the bottle?

I divided the amount i use to filter one batch by the amount of bottles and put that amount a single bottle, left it for over a week, still it smelled awful.
I think what phantom is refering too is that with the pipe metod the impurities get trapped in the filter pipe where as leaving it to soak the spirit is still in contact with the impurities? Well thats my guess
*Pipe filter is the way to go IMO