A question for those who carbon filter.

[confederatecondenser]

I have not been carbon filtering but started experimenting with it. I have ran two test samples thru my gravity filter and in both cases the hooch tested half the alcohol content when it came out as it was going in. In one case 60% dropped to 35%, the other 85% dropped to 43%. Thats 85%, tested w/ a hydrometer before filtering, and testing 43% after filtering.
Every thing I have read on this denies that activated carbon will filter (remove) alcohol from liquid. I have in my life drank about the same amount of hooch as it would take to float a battle ship. I know what alcohol taste like, and it taste like it is not there. The hydrometer says half of its gone. I am having a hard time convincing myself that its not half gone. Thanks to anyone that can shed some light on this subject.

I am filtering with a 48 inch stick of 2 inch pyrex tubing stood upright on a make shift stand. The bottom end is covered with a section of material cut from a filter bag secured w/ a zip tie. Inside the tube several coffee filters are packed in the bottom against the filter bag covering the end. The rest of the tube is filled with activated charcoal pellets. Some were crushed into smaller pieces and put in first then topped off with the regular sized pellets. I pour it in the top and it drains out the bottom.

The properties of the charcoal pellets are as follows:

BITUMINOUS ACTIVATED CARBON CHARCOAL
Total Surface Area (BET), m2/gm= 1050-1150
Iodine Number, mg/gm= 950-1000
Apparent Density g/cc= .50-.52
Apparent Density lb/ft cubed=31-
Hardness Minimum=98.5
Particle Size=4mm
Moisture Max=3%
Low Ash Content
No Coconut
Uniform grain size

[flip]

I used carbon of 1mm cranials size or less , spike 1.5m high,carbon must be cooked and saturated with water, no air in it before alcohol is added to water ,drain until you taste alcohol then you start collecting.and alcohol percentage at start be at 50 percent,mine dripped very slowly.

well i did not test the percentage thereafter so ,sorry but it surely softened the taste
i dont do it any more ,carbon is scarce here and is expensive to ordering, i come right without it
a spesific procedure is to be followd ,otherwise one will have trouble .

[kiwistiller]

did you prime your carbon with alcohol or water before using?

[confederatecondenser]

Kiwistiller, I washed the charcoal with water, the 20 oz. or so that I crushed into fine pieces had to be wrapped in a cheese cloth type material to wash free of dust without loosing what was needed. The larger pellets were just rinsed in water several times and loaded into the filter on top of the finer grains.
As far as priming, I ran water thru the filter prior to the hooch but there was air in between the two.
I am happy with the way the filter is smoothing out the hooch but I am confused about the drop in alcohol content. I just ran a sample thru that came off the second run at 73 % with a bit of a lingering bite to it, I
cut it to 60 % with filtered water. I then ran the 60% thru the filter and it ran out of the filter at 35% or 70 proof. You don't get a drop in purity when you filter? I am trying to put the pieces together here. Thanks for the help. CC

[kiwistiller]

the drop will most likely be from dilution with the water you've put through it. keep feeding it booze and the proof will rise.

Also, I'm fairly certain that carbon filters aren't so great over 50%? I don't use one much anymore, but they're bloody useful for cleaning up mistakes. I checked mine the other day and it's gone mouldy, damn it.

[father william]

How much distillate are you running through that column? If it's not a lot, I agree with Kiwi: you're leaching water out of the carbon and diluting your shine.

Another thought is that your covering at the bottom of the funnel is so tight that the water can't drain out before you're pouring your distillate through, but eventually comes out with the (diluted) distillate as it progresses through the column.

I use a funnel with a coffee filter in it, 5" diameter, 5" tall, opening is about 5/8" across at the narrow end. Fill it about 2/3 of the way up with carbon. Not a whole lot of carbon, but it works fine for polishing.

I microwave some tap water until it's hot but not boiling, then pour that through the funnel several times while my stock pot is warming up. Hot water is far superior to room temp in making the carbon absorbent. Also, after wetting it and letting it drain, I pick up the funnel and give it some up-and-down shakes over the sink. That gets any excess water out of the funnel so that it's damp/wet but there's no standing water in the funnel, and it's all packed down into the bottom.

That's been working for me great. It removes any grain oils, removes copper salts that the acidity of the wash bring through the condenser into my collection vessel, and extends the run into the tails a little bit, without sacrificing much flavor.

[confederatecondenser]

F.W. you may be on to something. As I mentioned earlier I ran just over a liter thru at 60% that came out 35%. Well I just ran another liter of the same batch of 60% and it came out 45%. So the proof may be increasing as the water is washed out. I don't have any water collecting in the bottom of the filter but I am using a lot more coal in my filter than you are so there may be ample water contained in the coal itself to reduce the proof of the product. If you are getting good polishing results from a funnel full of coal then I may need to reduce the amount in my filter. This would lessen the amount of water it could hold and reduce the diluting effect I am getting. This would also free up more tube at the top to hold the hooch poured in reducing the trips to refill the tube. C.C.

[confederatecondenser]

Just bringing a little closure to this one. I have to believe you guys were on the right track when you suggested the carbon may have been holding water from the "flushing" of the filter prior to running the hooch thru and releasing some water into the hooch causing the drop in alc. content. I say this after running several liters thru the carbon with no water in between and the purity of the out put is closer to that of the input with each run. This sounds all as if it has been solved , until you think about the many folks who run water thru their filter and back it up with hooch. Why is it that they are not getting the same effect as I was.

[Dnderhead]

even useing charcoal you will loose about 5%.i believe some is absorbed into the carbon and not released.

[father william]

even useing charcoal you will loose about 5%.i believe some is absorbed into the carbon and not released.

Ethanol is electrostatically neutral relative to activated carbon, as is water.

Imagine a child's balloon, inflated and rubbed on your hair, then held above the carpet. It will pick up dust and stuff via static electricity.

Activated carbon works like that. It doesn't work like a sponge.

I'd guesstimate losses in the 1-2% range if you allow the carbon to drain well beyond when the last distillate is poured through it. There's some evaporative loss, but it's acceptable.

[Dnderhead]

I know that, but that stuff is porous, and holds water, if it holds water it will hold alcohol. now witch will go into those microscopic holes easier water or alcohol? so unless you rinse it after some alcohol will stay in it,
now ,,what Im saying you rinsed the charcoal, now it is full of water, then you add alcohol, the alcohol displaces the water,, now you have alcohol in the charcoal,and the water it displaced is diluting the product, now if you continue to use it it whould not dilute any further.

[father william]

I know that, but that stuff is porous, and holds water, if it holds water it will hold alcohol. now witch will go into those microscopic holes easier water or alcohol? so unless you rinse it after some alcohol will stay in it,
now ,,what Im saying you rinsed the charcoal, now it is full of water, then you add alcohol, the alcohol displaces the water,, now you have alcohol in the charcoal,and the water it displaced is diluting the product, now if you continue to use it it whould not dilute any further.

Considering the fact that a molecule of ethanol is much larger and more complex than a molecule of water (one of the smallest and simplest in nature), I don't see why ethanol would necessarily displace water in the wetted carbon.

[Dnderhead]

that is easy enough to prove or disprove, put activated carbon into a jar,, add a measured amount of alcohol,cap as not to loose by evaporation. what a day or so ,then pore off alcohol to see if you git it all back.

[father william]

As long as the carbon is already wetted before the experiment, I agree, it would solve the issue.

If it's dry when it goes in the jar, it wouldn't prove anything.

[Dnderhead]

That should not make any difference, I was just told that alcohol whould not go into the charcoal. that alcohol molecules are to larg .so none should be absorbed even if put in dry.
Now my idea is you soak/boil the carbon. then it is full of water,, then the water dilutes your product.
if the water comes out to dilute . then something has to replace the water or the pores has to shrink . that is why I believe that it does both,, the water is diluting your product, but also some alcohol is in the charcoal. there is another way of testing.
to see if alcohol is in the charcoal, put some used charcoal in a pan, heat and see if the vapors ignites. if it does it has alcohol.if not then water.

[pistachio_nut]

I was dreaming up a carbon filter tonight on the way home from work, I'd like your feedback on the idea.

I was thinking about putting together an inline carbon filter for the output of my still. The product comes out of the spout, through a hose to the carbon filter, and drips out into a collection container. The carbon filter would be a three inch diameter stainless steel pipe in three one-foot sections. Each one foot section would be topped by a funnel three inches in diameter. The purpose of the funnel is to collect the product from the sides of the pipe and redirect the flow into the center of the carbon. The bottom funnel would be fitted with a needle drip valve that would direct the flow into the collection container.

The procedure would be to hot water activate the carbon before the run by pouring boiling water into the top funnel until the carbon filter has soaked in boiling water for ten minutes. After the water has mostly drained off, the flow from the still would be directed into the carbon filter.

I would then cut the first liter or two to run through the still in the next batch. I do a lot of fruit macerations, so having a higher ABV is important to me. If I use a 180 proof product, I probably wind up with an 70-90 proof final product because so much water comes out of the fruit.

What do you think? Anybody have experience with this kind of a thing?

[Ayay]

Hi p_n, It's a waste of time to carbon the heads and tails. Re-stilling them and making good cuts will do much more purifying than carbon can. Better to only filter the hearts after making the cuts...but good cuts and good hearts don't need carbon!
- Carbon removes neither foreshots nor heads, only a little tails stink or unwanted smells/tastes that sometimes get in.
- Carbon will take out the fruit flavours.
- The only hose for high-proof output is a copper hose.

[rad14701]

Carbon won't change the composition of what you have for foreshots, heads, hearts, and tails... The best advice we can give is to learn to make clean washes that will produce clean spirits... Higher or lower alcohols will not be chemically altered by carbon filtering, they will just be clean higher and lower alcohols... Properly distilled ethanol, with proper cuts and blending, shouldn't require carbon filtering...

[blanikdog]

... Properly distilled ethanol, with proper cuts and blending, shouldn't require carbon filtering...

Yep rad. There's no easy way or shortcuts. Attention to the entire process is the answer. IMHO anyway.

blanik

[confederatecondenser]

Carbon won't change the composition of what you have for foreshots, heads, hearts, and tails... The best advice we can give is to learn to make clean washes that will produce clean spirits... Higher or lower alcohols will not be chemically altered by carbon filtering, they will just be clean higher and lower alcohols... Properly distilled ethanol, with proper cuts and blending, shouldn't require carbon filtering...

I agree fully with you on making proper cuts as the only right way to get a clean tasting spirit. But I will add that every time I have carbon filtered, according to my hydrometer, I lost abv.. I can't explain it but it is what it is and I have gone back to making shallower cuts and running the rest again on another day.

[diesel4ever]

I carbon filter all my neutrals because it removes any trace impurities and makes my 100 proof vodka taste like 30 proof vodka. YUMMM! I never prewash my carbon and 100 proof comes out 99 proof. If you use a fine stainless screen in your output end of your filter and cover the mouth of your collection jar with an unbleached coffee filter, your final product will be very clean. Edit: as rad and others have said though proper fermentation of your wash and being picky on your cuts is really important also.

[rad14701]

confederatecondenser, you aren't the first person to notice a drop in %ABV after running spirits through activated carbon... It's entirely possible that the carbon is trapping a bit of alcohol across the range from low to high... If your spirits are coming out clean then just consider the drop to the the angels share...

[confederatecondenser]

Angels gotta get by on something. You know from the first batch of hooch I made, I have not had a bad one. Some better than others but its all been better than most I have tried from other stills. I do say most because I have tried some corn hooch that was indescribably great. I may never be able to reproduce what was in that jar and may be no-one can. It was a one time thing from being at the right place - right time and it was a flavor I will never forget. A law man I knew gave it to me and said it was seized from an old man when they followed up on a tip he was cooking. The guy told me it was to damn good to destroy when he handed me a quart jar of it. I did not cook then but looking back I wish I had bailed that guy out so he would owe me a favor. My point is no matter how good yours is, its an ongoing thing to always make it better and before I started trying to perfect my hooch I did not have an understanding of the value of the knowledge that some of these old timers have taken to the grave. I wonder if they did.