Originally By Tony Ackland
Methods of Polishing SpiritsI do a two stage polishing process. Firstly i soak my alcohol with carbon for a couple of weeks - eg just pour the carbon into the storage container, swirl it around, then let it sit, giving it a shake every so often. When it has sat long enough, I then pass it through a second filter. This is a longish tube with a small hole in the base of it. I pack a little filter/tissue paper into it, then fill it with finer/secondary carbon. I attach a softdrink bottle of the spirit upside down to the top of the column, and let the alcohol slowly drip through - about one drip per second. (Actually, to be honest, I quite often dont do the second step - simply decant the clean alcohol out of the container while all the primary carbon is still sitting on the bottom. Tastes just as good.)
There are products available to help you do this easier. One is a container which you mount on the wall, which is plumbed with a valve and hose sticking out the bottom of it. Attached to the hose is an inline filter (the sort used for garden hoses). The filter is packed with the secondary carbon. When the spirit has had enough primary polishing, simply open the valve, and run it out through the inline filter. Simple.
Glenns set-up is very similar ...
When you have finished filtering your spirit, do a final filter using say 250-500mL of water. This will flush the remaining alcohol which is wetting the carbon, and save you from throwing it away. Put this back in with the next wash you distill.
Kez has optimised this ...
So yesterday I put in a litre of hot tap water instead of cold.
This told me 2 things.....
1. I could feel in the tube where the water was and it told me that all the carbon was being used in the filtration.
2. When the water was about to come thru cutting down on about 18 tastes, YES!
To celebrate my new knowledge I had a couple of scotches. I love it when a plan comes together.
To remove any of the very small carbon carbon particles left in the spirit, you can pass it through very fine filter material - down to 1 micron pore size. This will leave it crystal clear and clean.
From Cheryl (Victoria, Canada)...(posted on http://groups.yahoo.com/group/Distillers)
Simply make a pure sugar mash, using turbo yeast or whatever else you have handy. Ferment it out and distill it to 95% (or the best of your stills' capability). Dilute the spirit down to 40 to 50% and age it for a month on some uncharred American oak chips. About 2 tablespoons per gallon. Let this sit a month, until a nice oak flavor can be tasted in the spirit ( I try for Glenmorangie Scotch/gold in color), almost like a bland, one-dimensional, failed bourbon whiskey. THEN filter out the oak chips, add your carbon, and treat it as you normally would any sugar vodka. I have tried this with a small test batch, I am now soaking oak chips in ALL my vodka- even the stuff already carbon polished (I'll just re-polish it). After carbon treatment, there is no color and no wood flavor. The taste, however, is markedly improved. It tastes just like the wonderfull once-a-year-distill-all-the-remnants-I've-never-gotten-around-to-bottling batches people come up with now and then, but it can be done consistantly now! Appearantly the acid and tannin content in the oak mellows the spirit out through various chemical alterations/combinations, and these beneficial changes are noticable even when the flavoring compounds they form have been removed by carbon. Your sugar vodka will be the best in the neighborhood after this-and just as water-clear. Give it a try!
Jack agrees ...
AuntyEthyl describes his setup ...
Secondly I apologise for the drawings, when it comes to Artistic, I'm all Autistic.
1 x 500mm long 50mm diameter upvc pipe
1 x 50mm end cap
1 x 50mm threaded adapter
1 x 50mm threaded end cap with O ring
1 x poly pipe barbed adapter (see drawing/see text)
1 x Caulking gun glue tube nozzle
1 x Aquarium air tap
1 x 1 meter+ of silicon aquarium air hose
20ltr drum with tap
Container to collect treated spirit (I use a fermenter)
Some coffee filter paper
Some untreated spirit
After studying my ordinary drawings, drill a hole in the centre of the end cap to suit the nozzle. This can be glued into position with silicon, from the outside. The end cap can then be glued onto the end of the main pipe. The barbs on the poly pipe fitting need to be filed down flush with the outside of the fitting, then a suitable hole drilled into the centre of threaded cap, and the poly pipe fitting glued into place. The threaded adapter can be glued onto the other end of the pipe.
With the main filter unit built, all you need is a short piece of plastic tubing to fit over the barbed poly pipe fitting, then other end fits over the end of a standard drum tape (not the cobra/flip type tap)
To the caulking gun nozzle attach a short peice of silicon tube. The other end is attached to the air tap. A longer peice of silicon tube is used from the tap, leading into the collection container.
When you are ready to use...
You could even set up a recirculating system to do the filtering .... Jan asked about this ..
This produces a vastly superior product in a fraction of the time. Using a 2 or 3 stage process like this can lead to vastly shortened treatment times with each stage in the treatment process optimised.
In the vessel mentioned above I have a tyre valve fitted into the stainless steel lid and by using a bicycle tyre pump together with a precise pressure guage I can quickly pressurise the setup to about 2 psi which seems to be about the ideal pressure and which allows me to final polish 1 litre of spirit in about 1/2 hour. The final product is as fine treated product as you will find being crystal clear and even when left for weeks has absolutely no settlement or sediment. When left to just decant by itself (everything running downhill and thus gravity controlled) it took 24 hours + previously to filter the same volume. In this setup as stated I found 2 psi to be the best pressure although you may find it varies a bit with your own setup. Exceeding this pressure quickly led to possibly channeling with the alcohol being forced through too fast and some very minor carbon settlement resulting.
At the end of the day I found treatment and filtering rates were largely determined by the type and degree of fineness of the filter material used. Constant circulation led to shorter treatment times and ultra fine filtering led to a superior product. The main things are not to be too frugal with the carbon or to expect too long a life out of the filters. If using this method I suggest you do your own trials and tests especially of settlement and sediment. Even the clearest alcohol initially when left for some time will show very minor settlement. It is this aspect that with experience and patience you can gradually get perfect.
Jan writes about freezing when filtering ...
The 1982 US Bureau of Alcohol, Tobacco and Firearms (BATF) regulations define vodka as neutral spirit so distilled or so treated after distillation, with charcoal or other materials, as to be without distinctive character, aroma, taste or color. The use of charcoal filtration is now optional, whereas in earlier regulations it was mandatory and even the time and amounts of fresh charcoal to be used were specified. This change is in recognition of the relatively recent improvements in the quality of neutral spirits. Vodka is generally taken to be odorless, tasteless and colorless ethanol, but in the past in Eastern Europe vodka was lightly flavored with grasses or herbal extracts.
It should be stressed that not only is the charcoal treatment nonessential, it is also not particularly effective and will not make a poor quality, improperly rectified neutral spirit into a good quality vodka. Neutral spirit should be diluted to about 55% before charcoal filtration. The old BATF regulations (1961) specified dilution to between 55% and 40% at a minimum contact time of 8hrs with 10% of the charcoal replaced every 40hrs to give a minimum usage of 6 lbs of new charcoal per 100 gallons of spirit treated.
This was usually achieved by passing the diluted spirit through a series of eight or nine cylindrical charcoal filtration beds in a slow, continuous flow with one of the beds changed every day. The fresh bed would be connected last in the series. This meant that the beds were constantly being rotated; so the preferred arrangement was to set the beds in a circle to facilitate the changing. A simple alternative treatment method is to add charcoal to diluted neutral spirit in a tank and agitate or circulate it through a pump for a suitable length of time.
The water used in the initial and final dilutions should be clean, odorless and preferably demineralized. The demineralization is generally for aesthetic purposes as consumers do not like to see a white film of salts around the side of a bottle or glass if the vodka has been allowed to evaporate.
In countries where laws require that all spirits be aged in wooden barrels, it may be necessary to add a small amount of sugar and/or glycerin to be able to classify vodka as a liqueur or a compound spirit rather than as an immature spirit. The amount of sugar or glycerin used is normally the minimum required to provide proof obscuration. This occurs when there is sufficient dissolved material to cause the apparent proof obtained by direct testing to differ fractionally from the real proof obtained by distilling the ethanol from a sample in a laboratory still and retesting after redilution to the original sample volume.
Great care should be taken in the bottling of vodka to prevent contamination with residues of other odorous products. The tanks and bottling systems should be washed thoroughly if previously used for other products. However, some bottlers prefer to keep a set of tanks and a bottling line dedicated solely to handling vodka. For further reading on vodka processing seethe reviews by Simpson (1977) and Clutton(1979).