Carbon

[Kenster]

I found this info, which i thought might help some misguided souls...

What is activated carbon?
Contrary to what many people believe, activated carbon is not charcoal. Several terms are thrown around by people who are referring to the same thing, but in reality they are thinking of entirely different products. The most commonly misused terms that people use when they mean to refer to activated carbon are carbon and charcoal. Carbon is actually a chemical element, found on the periodic table. Charcoal is essentially a porous form of carbon that is the result of burning a product, such as wood, in the absence of air. This may sound like nitpicking, but to avoid confusion and ensure that you have the correct product for filtering your spirits, it is important that the correct term be used. Some flavored spirits, most notably some whiskies, are actually filtered through charred wood. This filtering will not strip a substantial amount of flavor, but it does pull out some of the more harsh congeners, resulting in a smoother product that still contains the desired flavor. If this same product was filtered through activated carbon, it would strip most of the character and flavor, resulting in a very upset head distiller. Hopefully you now understand the importance of using the correct term, and if in any doubt, clarifying what you are referring to so that you obtain the correct product. Activated charcoal is another term that is often used when referring to activated carbon, but this term is technically correct. Note that the key word in all of this is the word “activated.” Activated carbon is produced from many different products through a combination of carbonization and chemical activation to create a carbon with many tiny pores of different sizes.
There are literally hundreds of types of activated carbon available, of which only a few are suitable for the filtering of spirits. It should go without saying that you should use only food-grade activated carbon. There are many types of activated carbon that are not intended for use in human food applications, so do not assume that all activated carbon is human food grade. Beyond simply being food-grade, there are other factors that affect the ability of any given activated carbon to strip congeners from your spirit, resulting in a clean, neutral product. Choosing an inappropriate activated carbon will not simply be less effective, but it can actually reduce the quality of your spirits by leaching deposits from the carbon that will end up in your finished product.
The type of material that the activated carbon is manufactured from, along with the exact activation method, will result in an activated carbon with different pore structures. Not all activated carbon is suitable for alcohol filtration, or even liquid filtration, for that matter. The optimal end use for the activated carbon depends greatly on the pore structure within the grains of carbon, as well as the format of the carbon. The basic formats for activated carbon are powdered, pelletized, and granular. Powdered carbon is not a usable format for most liquid filtration as it will quickly pack, forming a mud-like product that will not allow liquid to pass through it in a manner that is conducive to spirit filtration. Pelletized carbon, which is formed using powdered carbon under high pressure, is often used in water filtration (e.g., fish aquariums), where the water will be continuously circulated through the carbon or otherwise has an extended contact time with the carbon. It does not offer a large surface area or provide good access to the carbon pores when using standard spirit filtration methods. While both powdered and pelletized activated carbon have many uses, neither of these types is suitable for alcohol filtration.
Now you know that you are limited to granular-activated carbon, but there are still many types to choose from. So how do you know which is best? Ultimately, the “best” carbon depends on exactly what is to be removed from the liquid and how you intend to go about the filtering process. What we do know is that a larger percentage of the molecules that we wish to remove from our spirit measure between 2 nanmeters and 10 nanometers in size. These molecules will become trapped in the pores of the carbon, which is a process known as adsorption (not to be confused with absorption). This brings us back to the pore structure of the activated carbon. To trap these molecules, we will need to have an appropriate pore structure in the carbon. There are three types of pores created in the carbon during the activation process: macro pores (larger than 25nm), meso pores (1nm to 25nm), and micro pores (smaller than 1nm). Given the size of the molecules that we need to trap, the macro pores will have little effect on our spirit, as most of the compounds can flow right through without becoming trapped. At the opposite end of the spectrum are micro pores, which are too small to allow most of the compounds to even enter the pore. Meso pores, on the other hand, are of great value. The percentage of each pore type within the activated carbon is controlled by the selection of base material used and the activation process employed in making the activated carbon.
The two methods of making activated carbon are chemical activation and steam activation. Because most chemically activated carbon is wood-based and usually ground into powdered form, it need not be discussed at length. Steam activation is employed for most of the materials that are used in spirit filtration. The most common materials used for activated carbon intended for alcohol filtration are peat, stone coal, and coconut shell.
Peat-based activated carbon has primarily micro pores and meso pores, making it ideal for alcohol filtration. Unfortunately, it is difficult to obtain for the average hobby distiller, and because it is a relatively soft form of activated carbon, it does not hold up well to regeneration (the cleaning of activated carbon for reuse).
Stone coal–based activated carbon is similar to peat-based activated carbon in that it has a high percentage of micro pores and meso pores. This type of activated carbon is much more widely available than peat-based activated carbon and comes in a variety of grain sizes. Being a much harder carbon it is also better suited for regeneration, which can reduce the cost by allowing use of the same carbon multiple times.
Coconut shell–based activated carbon contains almost exclusively micro pores, but it can be extremely effective in alcohol filtration because the extremely large number of micro pores in the carbon can trap molecules at the entrance to the pores. This is only effective with very slow filtration, but it can make coconut shell–activated carbon among the best choices for alcohol filtration as a result. Coconut shell–activated carbon is also a physically hard carbon, making it suitable for regeneration.
Grain size is another consideration that you must give thought to when selecting your activated carbon. Grain size is often expressed either as mesh size range (e.g., 20x40) or the physical size of the granules (e.g., 0.4mm to 0.85mm). Both of these refer to the same thing, that being the size of the carbon granules. Mesh size refers to the size of the openings in a mesh screen. For example, No. 20 mesh has openings that are approximately 0.841mm in size, and No. 40 mesh has openings of approximately 0.42mm. This means that all particles 0.841mm and smaller are able to pass through the No. 20 screen, while larger particles are unable to pass through it. If the particles that pass through the No. 20 mesh are further separated using a No. 40 mesh, then all particles 0.42mm in size and smaller will pass through the screen. The granules that passed through the No. 20 mesh but could not pass through the No. 40 mesh will therefore fall between roughly 0.42mm and 0.84mm. Figures for this carbon are usually rounded to 0.4mm to 0.85mm when describing the granule size. The common mesh/granule sizes used in spirit filtration are 20x40 (0.4 to 0.85mm) and 14x40 (0.4 to 1.4mm). Most wood or peat carbon are of smaller granule size, commonly 18x60 (0.25 to 1mm).
Although the size of the grain does not affect the pore structure, it does affect how we must go about filtering to get the best possible results from filtration. A larger grain size, such as 0.4mm to 1.4mm versus 0.4 to 0.85, can do an excellent job of filtering and is more suitable for in-home regeneration, where the granules may get broken into smaller pieces. However, filtration must be done more slowly to be highly effective. Generally a smaller grain size will allow for faster filtration, but as the size of the activated carbon decreases, you can increase the risk of the filter becoming clogged, just as you will with powdered carbon. 0.4mm to 0.85mm (20x40 mesh) is a good middle ground, where the risk of the filter becoming blocked is minimal, speed of filtration is good, and it is widely accessible inexpensively.
Cleaning the Carbon
Once food-grade carbon has been activated, it is acid washed and then rinsed with water to remove water soluble minerals remaining in the carbon. It is not uncommon for the carbon to be poorly rinsed, especially with activated carbon made from base materials such as coconut shell, which can be more difficult to rinse. This can result in a deposit remaining in the activated carbon that will end up in your filtered product if the carbon is not properly rinsed prior to use. This is best done using a two-step process: first soaking the activated carbon in water, followed by rinsing.
These instructions are for a standard hobby-size package of carbon (approximately 104in3, 1.7L). If you are using a different volume of carbon, you should adjust all measurements accordingly.
Start by putting your dry activated carbon into a large container, such as a mixing bowl. Be sure to allow room for a few quarts of water to be added to the bowl along with the carbon. Bring approximately three quarts (about 3L) of water to a simmer and pour the water into the bowl. Stir the carbon gently and allow it to rest for a few minutes. You will likely notice an oily film on top of the water. Once the carbon has settled, pour the water off the carbon, being careful not to pour the carbon out with the water. Repeat this process at least three to four more times. This process will clean much of the deposit from the carbon while also saturating the activated carbon with water. By fully saturating the carbon, you will improve the efficiency of the filtration, as more of the distillate will be forced through the carbon instead of simply running around the carbon granules. You can further improve the saturation and resulting efficiency by adding simmering water after your final rinse and allowing it to sit undisturbed for 24 hours.
Although it is not necessary to follow the entire rinsing procedure with properly regenerated carbon, it is still necessary to add simmering water and allow the carbon to become saturated prior to the filtration process. Failing to do this will dramatically reduce the efficiency and effectiveness of the activated carbon filtration.
Secondary rinsing is done as part of the startup process for the spirit filtration, as outlined below.
Alcohol Filtration
The most effective method for activated carbon filtration is the one that allows you to force the maximum amount of liquid through the pores in the carbon so that the largest number of contaminants are trapped inside the granules of carbon. As discussed, activated carbon does not use ionic charge to remove contaminants. Activated carbon works by trapping molecules within the carbon itself, so to be effective, we must find a way to force the liquid through the carbon as opposed to just channeling it around the grains of carbon. Wetting the carbon during the rinsing process lays the groundwork, but we still must employ a method that encourages the liquid to channel through the carbon and not around it. Always remember that most particles are lazy, so they will take the path of least resistance as they make their way through your filter system. That path is usually around the carbon, unless you set up your activated carbon bed appropriately. This is precisely why tossing carbon into a container with your spirits will do very little. While a small amount of spirit will flow through the carbon’s pores this way, the overwhelming percentage will not. Most of the spirit is quite happy to just flow around the granules of carbon as they settle to the bottom of the container. You may hear that shaking the container regularly to rouse the carbon will help. Indeed, each time the carbon settles, some of the liquid will flow through the carbon instead of around it. However, what about the liquid that flows through the pores in the opposite direction from the previous time? It can dislodge molecules that were previously trapped in the carbon, releasing them back into the spirit. To use activated carbon to efficiently and effectively remove the residual flavor and aroma compounds remaining in the spirit after distillation, you must force the maximum amount of liquid through the carbon so that the congeners are trapped and removed from your product. The best way to do this is by creating a long filter bed that maximizes the liquid’s contact with the activated carbon.
Another consideration that we must take into account is the proof of the spirit that you will filter. In most cases, if you attempt to filter undiluted spirit, say 90%abv or more, your filtration attempt will prove unsuccessful. The high-proof spirit has a lower density, and as a result this thinner consistency liquid will usually channel around the carbon granules, resulting in negligible improvement. To ensure consistent, effective results, you should dilute your spirits to no more than 55%abv prior to filtration. While you can dilute your distillate further, there is no reason to do so at this point, as it simply increases the volume of liquid, and therefore the time involved to filter. You can further dilute your filtered spirits to the desired proof later. This also allows for the small amount of dilution that will take place during the filtration process.
To obtain the maximum contact time and liquid interaction with the activated carbon, it is best to employ a long, narrow tube that you will fill with your activated carbon. This creates the greatest likelihood of spirit flowing through the pores of the carbon, where the contaminants will be trapped. The result is the cleanest possible finished product.
In commercial distilleries, it is common to use a pump to pump the spirit up the column as opposed to using gravity to feed the distillate. This allows a greater level of control over the speed of flow, as well as being optimal for steam regeneration, as pressurized steam can be fed from the top of the filter column, forcing many of the contaminants in the carbon out of the pores, vaporizing them, and carrying them out to a drain. This is not economically feasible in a hobby-level activated carbon filter system. Instead, we use a gravity feed system and try to regulate the flow rate either by the number of filter papers used (to control resistance) or with a valve on the output.


A basic activated carbon filter system is both simple and inexpensive to build. There are also several commercial filter systems available, ranging from low-cost plastic systems to high-end stainless-steel filters. If building or purchasing a plastic filter system, be sure to use only food-grade, alcohol-tolerant parts. The most common types of tubing for hobby distillation filtering systems are PVC and ABS. If given the option, you should select ABS plastic, as it is more tolerant to ethanol than is PVC. This is important even at the reduced strength involved during filtration.
Shape and size of the filter is of paramount concern. A square filter—or any filter shape with distinct corners—creates far too many void spaces that are not filled by the carbon. As a result, the spirit will channel through these void areas and not be forced through the carbon, or even between the grains of carbon. If the filter is too narrow, then the spirit will often channel down the walls of the filter, bypassing almost all interaction with the activated carbon. In both instances, the result is that there will be no substantial improvement to your spirits. Always opt for a round tube with a minimum inside diameter of 1.5 inches (40mm). An optimal volume of activated carbon for two to three gallons of spirit (a common volume of 50%abv spirit resulting from a six-gallon distillation) is around 100 to 110in3 (1.6 to 1.8L). To obtain this volume using a 1.5-inch-inside-diameter tube, you will need the length to be approximately 60 inches:
Volume = πr2h
Volume = 3.14159 x 0.75”2 x 60”
Volume = 106in3
Using a larger-diameter filter tube will allow you to reduce the length of the tube in relation, as it will still provide the same amount of contact time with the carbon. Similar to distillation, increasing the diameter of your filter column can allow for an increase in the speed of filtration, but only if the overall volume of activated carbon being used increases accordingly. This is how commercial distilleries are able to filter a large volume of spirits relatively quickly. Just as with distillation, patience will pay off, as filtration is far more effective when done slowly. A good filtration speed using a 105in3 carbon filter is 1 quart (946ml) per hour, although up to 2 quarts (1.89L) per hour is generally very effective.


Building your own carbon filter is very simple and cost-effective. You already know that a 1.5-inch (40mm) tube that is 60 inches (1.5m) long will act as a very effective filter tube. As luck would have it, 1.5-inch food-grade PVC tubing is available at virtually all home building supply stores and for just a few dollars.
On top of the filter, you need some form of reservoir, unless you are willing to stand beside the filter and constantly add your unfiltered spirit. I didn’t think so. A great, low-cost option is a large, food-grade plastic funnel. You may find a suitable funnel at a department store, but in all likelihood you will need to go to your local homebrew store for this item. There is no magical perfect size, but the larger your funnel, the less often you will have to check on it or top it up. Next you will need some way to seal the funnel to your filter tube. If the connection between the funnel and filter tube is not sealed, then liquid will seep out through the connection. There are many options for this step, from silicone gaskets to permanently connecting the two parts with food-grade adhesive.
You now have a filter tube with reservoir, but you still need something to hold the activated carbon inside the filter tube, control flow rate, and filter the tiny particles of carbon from the filtered spirits. All three of these tasks can be handled by affixing filter paper(s) to the bottom of the filter tube. This is most easily done by wrapping the filter paper(s) around the bottom of the tube and holding them tightly in place with a large stainless-steel hose clamp. The number of filter papers to use will depend on the type of filter paper that you have selected. While two to three commercial filter papers will usually be sufficient, if you decide to use coffee filter papers, you will require considerably more to avoid tearing and to decrease the speed of filtration. Now you just need to decide how you will suspend the filter above your collection container (hint, standing the filter in a colander that is situated above your collection container works very well).
Congratulations! Your filter system is built and ready to use.
The filtration of spirits is considered by many people to be a slow process, but it does not need to be annoying or a hassle. You have already prepared your activated carbon, and your filter system is built and ready to go. Filtration, unlike distillation, is not a process that you need to be constantly present for. Providing you remember to top up your reservoir before it is completely empty, this can be a relatively painless but very worthwhile process.
It is now time to move your wet carbon into the filter. Because the wet carbon tends to fall down the tube in heavy clumps, it is best to support the bottom of the tube by balancing it on a solid surface to avoid tearing the papers. Add approximately 1 pint (473ml) to the filter tube to slow the descent of the carbon and help build a consistent filter bed. Begin transferring your carbon to the filter using a serving spoon or ladle. After each addition, tap the side of the filter tube lightly to reduce gaps in the carbon. Once all the carbon has been added to your filter you can start the secondary rinsing, followed by the spirit filtration.
The secondary rinsing serves two purposes. First, it rinses away the last of the deposits in the carbon that may not have been removed during the previous rinsing and wetting procedure. Second, it helps to reduce any air gaps between the carbon granules, which reduces the channeling of liquid around the carbon and maximizes the flow through the carbon. To perform this step add approximately one gallon (3.78L) of hot water to the reservoir. The reason to use hot water will be evident in a moment.
When the water in the reservoir has nearly disappeared below the top of the carbon, start adding your unfiltered spirits. DO NOT LET THE WATER OR SPIRIT LEVEL DROP BELOW THE TOP OF THE CARBON! Doing so will allow air to enter into the system and require you to reset your filter by running at least a gallon of water through the system to rid it of air. Always start adding your spirits before the water has completely drained from the reservoir. Yes, this will result in a very small amount of dilution, but that is to be expected during the filtration process and is one of the reasons to filter at a higher proof than is meant for consumption. There will not be any dilution in the filter column, as both the water and spirit are moving down the tube at the same rate of speed.
Collect the liquid that is dripping from the filter, keeping a second container ready to start collecting your spirits separately when they begin to emerge. This is the reason for starting the filter using hot water. Your spirits will be cool—likely around room temperature—so by touching the filter column you will be able to actually feel where the water and alcohol are located as they move down the filter tube. When the alcohol has nearly reached the bottom of the filter tube, change your collection container to begin collecting your filtered spirits. Discard the water in the other container. Feel free to smell and taste the filtered product and note the difference between it and your unfiltered distillate. There should be a marked reduction in smell, flavor, and even the amount of “burn” on the tongue.
Continue adding your spirit to the filter reservoir. When the last of your unfiltered spirits have been added to the reservoir, it is time to start preparing for the final stage of filtration by heating a gallon (3.78L) of water. Just as you started adding spirits to your reservoir just before the last of the prep water disappeared below the top of the activated carbon, add the hot water to the reservoir before your alcohol has disappeared from sight. This water will help to push the alcohol through the system, leaving primarily water in the spent carbon and not wasting your valuable spirits. You can again feel on the filter tube where the alcohol and hot water meet as they progress down the filter column. Once the water has reached the bottom of the filter, you should replace the collection container with another container. Your alcohol is now ready to be further diluted and aged, flavored, or used as it is.
How to Know If Your Carbon Has Reached Its Capacity
As molecules become trapped in the pores of the carbon, they also begin to block those pores, rendering that portion of the carbon unusable. At the start of filtration, the carbon near the top of the filter will be actively removing the contaminants, and as it becomes used to its full capacity, the active area of filtration will slowly move down the filter column. The pores will gradually all become blocked by molecules that have been trapped, and the only way for the liquid to flow is by channeling around the carbon. When all the carbon has been used to its capacity, any further spirit will simply pass through the system unfiltered. The goal, especially for those who do not regenerate their carbon (which is the vast majority of home distillers), is to utilize the carbon to its full capacity without going beyond that point and simply passing their spirits through the filter needlessly. This is the most economical use of the carbon. Unfortunately, there is no magic number for gallons of spirit to volume of activated carbon. The purity of the distillate (i.e., how many congeners remain after distillation), the type of carbon selected, the filtration process, and the speed of filtration all play vital roles in this equation. As a rough rule of thumb, you can expect to effectively filter two to four gallons (7.56 to 15.1L) of relatively clean distilled spirit at 50%abv through 100in3 of good quality, appropriately selected activated carbon.


Regenerating Your Carbon
Once you have used the carbon you may choose to discard it, or you may decide to regenerate the carbon so that you can reuse it for future filtrations. Commercially activated carbon is most often regenerated and used many times, but this is far less common among hobbyists. This is in great part because of the cost factor of activated carbon. Commercial distilleries have to be far more concerned with cost than the hobby distiller. That is not to say that cost is not of concern to hobbyists, but they are not driven by cost the way that a for-profit distillery is. By regenerating and reusing their activated carbon many times, a distillery is able to make the activated carbon cost negligible. So why is this process less common among hobby distillers? Simply put, regeneration can be a hassle on a small scale. Commercial distilleries will put up the capital cost to be able to regenerate the carbon, knowing that it will dramatically reduce the cost impact versus replacing the carbon once it has been used. It is certainly feasible to build the same type of equipment on a small scale, but the cost is not justified unless volume is substantial. It is difficult for the hobbyist to justify spending a few hundred dollars just to enable him or her to regenerate the activated carbon that costs under $10 per batch, but much easier for a commercial distillery to justify a cost of a few thousand dollars for the same purpose given that they will reuse the same carbon up to 100 times or more.
With that said, it is not entirely unreasonable for the hobby distiller to regenerate activated carbon for at least a second or third use. The reason that commercial distilleries are able to reuse their carbon so many times while the hobbyist is much more limited is because of the way that the carbon is regenerated. While the distillery will use steam to regenerate the carbon, the hobby distiller generally must employ a combination of boiling and drying. The process can be a hassle and also dangerous if proper care is not taken. This is why most hobby distillers simply discard the used carbon and buy new carbon for each batch.
Note: Regenerating your carbon can be dangerous! Many of the contaminants in the carbon are extremely flammable. Never attempt to regenerate activated carbon with a gas stove or oven. Always have a fan running to disperse the air to dilute the flammable vapors and keep a fire extinguisher handy. Never leave the carbon unattended. These instructions are for informational purposes only. Regenerating activated carbon is not suggested and is done at your own risk.
If you decide that you are going to reuse your carbon, you will start by emptying the carbon from your filter column into a mesh sieve. Using a standard kitchen colander will not work, as the holes are larger than the carbon granules and they will simply flow through and down the drain. Rinse the carbon extremely well with hot tap water. Next, place the carbon in a large pot on the stove and add at least twice the amount of liquid. Bring the water to a boil and allow it to continue to boil for a minimum of 15 minutes. You will literally smell the contaminants that are being removed. Continue to boil until there is no longer a noticeable smell in the vapor. The boiling process breaks the carbon down slightly, so the granules will generally be slightly smaller after boiling. This is the main reason why the carbon can only be reused once or twice. As the carbon breaks into smaller pieces with each boiling, it quickly becomes too small to be used in a carbon filter tube without causing a blockage in the flow of the liquid.
At this point you have removed most of the contaminants with a boiling point of 212° F (100° C) or less. However, there are still fusel oils with a higher boiling point that remain in the carbon. To remove the remainder of the contaminants you need to dry the carbon in an electric oven. Never attempt to dry the carbon in a gas oven, as some of the contaminants remaining in the carbon are highly flammable and can ignite in a gas oven. Heat the oven to 300° F (150° C). Place the carbon on a cookie sheet or other shallow baking pan and allow to regenerate for approximately three hours.
It is important not to rush the process by increasing the temperature of the oven. Most of the impurities remaining after boiling have a vaporization point below 285° F (140° F), but as the temperature in the oven increases, so does the possibility of vapors (or even the carbon itself) igniting, so never exceed 300° F (150° C) when regenerating your activated carbon.

[Zak Griffin]

Very interesting and informative stuff, just disregard the bit about making a carbon filter out of PVC pipe with a plastic funnel :handgestures-thumbupleft:

[Kenster]

Hey Zak, does that mean i have to throw away my PVC pipe and plastic funnel now?
Great read, i thought... except for that bit... should clear up some repetitive questions on this site.
Cheers...Ken

[Sam.]

. should clear up some repetitive questions on this site.
Cheers...Ken

:laughing-rolling: :laughing-rolling: :laughing-rolling: :laughing-rolling: sorry, found that pretty funny :laughing-rolling:

[Kenster]

Hey Sam i get it... some things arent that obvious... guess i am still a bit naive at 62.

[Sam.]

Hey Sam i get it... some things arent that obvious... guess i am still a bit naive at 62.

It was no dig at you mate, we have a fairly comprehensive newbie corner on the forum that only a small percentage read on signing up here ;-)

[gad]

to dry the carbon in an electric oven. Never attempt to dry the carbon in a gas oven, as some of the contaminants remaining in the carbon are highly flammable and can ignite in a gas oven.

Any suggestions if you only have a gas oven ?

[Kenster]

gad, i am not the expert, i just borrowed the text to share... BUT if you want my opinion on it...NOT IN A GAS OVEN...dont even think about it.
It is cheaper to buy n replace store bought carbon than blow you/your oven up.

[Nino]

Would a mini toaster oven work? You might be able to get one of those cheaply. Just throwing it out there maybe some can confirm or refute it.

[Undertaker]

In the weber maybe???

Cheers Phil

[Kenster]

Phil, dunno if a gas weber would be any good...same as inside oven i think(naked flame), we use a 'charcoal' one, too much smoke n shit, would not clean it.
Nino, i thought the same thing, one of those toaster oven things may well be the go if they could keep that sort of heat going for a while.
Besides, if it blew up , they are pretty cheap...lol (i cant do those smiley/laughy things)

[gad]

Sure glad I read this thread.
I'd previously read a thread about it, that Doc had had a fair bit of input into.
This is a part I'd recorded from that thread:
"You can re-activate it and re-use it forever, by simply boiling it for an hour, .... if you can no longer smell any funky off smells you are done ...., rinse with cold water, then put it on a tray (covered in ordinary baking foil (saves rusting the tray!)) into the oven at 220 degrees C for an hour and a half. Take out, put into filter ...run water through it to get rid of any voids and pack it in and you are ready to go ... repeat this process regularly."
No mention about not using gas ovens.
Luckily, so far, on the few occasions I've needed to filter, I've been using knew activated carbon, changing it regularly, waiting until I had enough to do this with.

Could have been disastrous :o

[Nino]

Phil, dunno if a gas weber would be any good...same as inside oven i think(naked flame), we use a 'charcoal' one, too much smoke n shit, would not clean it.
Nino, i thought the same thing, one of those toaster oven things may well be the go if they could keep that sort of heat going for a while.
Besides, if it blew up , they are pretty cheap...lol (i cant do those smiley/laughy things)

My toaster oven has a timer of 90mins and can heat up to 250C if you get one like that you could pre warm it for say 15mins then put the carbon in and reset it for 90 mins and away you go.

[Kenster]

Hey Gad... glad u r getting serious about what we should and shouldnt do... in terms of safety... good stuff.
Guess what i am sayin though is... Get with the TPW (or if you are into dark spirit, CFW...Zaks gear...) read up about the REAL need to use carbon...do good cuts...monitor run speed... type of unit(still)... and FUCKING FORGET CARBON...buddy....many here dont even go there...
not trying to sound like a prick...but i (as with many) havent used carbon for ages as (all of the above) help reduce yet another tedious/costly process in the whole 'lets make some DECENT booze' which we are all aspiring to produce...
good luck buddy...
If , however, you MUST use carbon as a final cleanser, and thats all good, try the Ninos mini oven...

[WTDist]

I dont carbon filter my white spirit due to coat but i much prefer the flavour of it after i filter it