Still Smart

I’ve seen a few articles recently where people have mentioned using Brita water filtering jugs to purify vodka, and I’ve also seen information about refilling your own Brita filter cartridges. I thought it would be a good opportunity to explore this area in a little more detail, and explain the science behind what is happening.

Can you make premium grade vodka from a cheap bottle of no-name spirit? Is it worth the effort and expense of buying the filter jug and cartridges? Is the process safe? I decided to find out whether a Brita jug has any place in the home distillers toolkit, or if it should remain the preserve of cheapskate student types and those who have too much time on their hands.

There seem to be a number of people online who claim that using a Brita style filter jug improves the quality of cheaper bottles of vodka – here is one example, and here is another. The US TV series ‘Mythbusters’ included this subject in one of their shows, and concluded that the filtration works to some extent, but doesn’t make a bad vodka into a good one. So how does a Brita filter actually work, and what is it designed to filter?

NOTE : Throughout this article I make reference to using a ‘Brita filter’ – this is merely because Brita are the market leaders in this field. The information applies equally to all filter jugs which share characteristics with them, such as the Morphy Richards jug that I own. There may be some differences in the filter components so if in doubt, check with your manufacturer before use.

What’s inside one of these things anyway?

I did some research, and found that a Brita cartridge is basically filled with activated carbon – this is the same stuff that you can buy from your local homebrew shop. There is a great document about activated carbon for home distillation use available here (highly recommended reading if you distill your own spirits), but thinking more along the Brita front, there is a page here from the City of Ottawa which states that :

Granular activated carbon filters can be effective in removing colour, taste, odours and some chemicals (certain types of organic chemicals and pesticides) if they are present in the water. These units can also remove some types of chlorine. Its effectiveness of this type of filter depends on its size and the length of time the water is in contact with the carbon. The larger the filter and the longer the contact time, the more effective it will be at removing these substances. The American Water Works Association has described small cartridge units that attach to the tap as “totally useless”, because of their size and the brief exposure time. Granular activated carbon filters by themselves will not remove lead and other heavy metals and will not soften the water.

WARNING: A granular activated carbon filter must be properly maintained. Once the filter becomes clogged, it will not operate properly. It may even release some previously filtered material back into the water, possibly in higher concentrations than was present in the source water. In addition, the presence of organic nutrients in carbon filters can promote bacterial growth, as quickly as overnight.

That last paragraph makes a very important point – considering the size of a Brita filter, this means that the described practice of running vodka through a filter jug several times will only work up to a point, and then your spirit will actually contain MORE of the nasty bits. Gert Strand says pretty much the same in his article here – there is only so much that carbon can remove before it loses its efficiency.

If you’re filtering store bought vodka, it should already be fairly pure anyway (at least in a relative sense; people drink the stuff so it can’t be too harmful as it is) and this is less of a problem than if you’re filtering something you’ve distilled yourself which could saturate the filter quite quickly if it’s not that pure. The bacterial issue should be less important with alcohol as it should kill many of them off anyway, but if you chop and change between using your jug for water and alcohol then it could be relevant.

TIP : You should only filter neutral spirits (such as vodka) with activated carbon, as it will also filter out some of the colour and flavour of other spirits such as whiskey, rum, etc. Unless that’s your bag of course, in which case go ahead!

Ion, like a lion, in Zion? Er, no… afraid not.

After that brief diversion, it’s back to the inner workings of the Brita filters. The cartridges also contain ion exchange resin beads; some people online have incorrectly assumed these to be filler material, added by Brita to lower costs. What these actually do is trap harmful metals from the water, and exchange them for another material – in the case of Brita filters, this would be hydrogen ions. Here comes the science bit!

As the metallic ions in the water affix themselves to the exchange material, the latter releases its hydrogen ions on a chemically equivalent basis. A sodium ion (Na+) displaces one hydrogen ion (H+) from the exchanger; a calcium ion (Ca++) displaces two hydrogen ions; a ferric ion (Fe+++) displaces three hydrogen ions, etc. (Recall that home softeners also release two sodium ions for every calcium or magnesium ion they attract.)

This exchange of the hydrogen ions for metallic ions on an equivalent basis is chemical necessity that permits the exchange material to maintain a balance of electrical charges.

Or to put it into layman’s terms, the metals are exchanged for hydrogen which is part of water anyway – again this process will eventually exhaust the ion resin beads in the filter, requiring a replacement cartridge.

When talking about drinking water, this replacement is obviously a good thing – you don’t want to be drinking those kind of nasty elements! However, those metals should not be present in a distilled spirit, because distillation itself is a method for removing them. There are a tiny number of heavy metals that could theoretically be present, as they have a vapour weight which is lighter than that of water. However, the chances of them being present in your water supply (and hence your distillate) is minimal, and even so the activated carbon should remove them.

The Brita’s Empire

To confirm all of this, I emailed Brita themselves and asked them about filtering alcohol using their filter jugs; specifically as to whether the ion resin beads would have any noticeable effect. Their reply was as follows :

BRITA have been asked about filtering alcohol before and our understanding (although we do not run tests on this) is that there may be a very slight reduction in alcohol content if filtered through a BRITA cartridge but the ion exchange resin will not have an effect on alcohol.

The ion exchange resin selectively removes certain metal ions such as copper, lead, calcium and aluminium from the water and as a weak acid cation exchanger ions removed are replaced with hydrogen ions, which combine with other ions and eventually form H20 and C02.

I hope this answers your query.

Yours sincerely

Rachel Laycock
BRITACare Manager
Brita Water Filter Systems Ltd

The one thing that confuses me about this reply is the part about the ‘reduction in alcohol content’. I’m no master scientist, but logically speaking if that is the case then it must be going somewhere or else something else is being added to dilute it.

Makes sense, right?

Hypothetically speaking, if something is being removed by the ion exchange resin and replaced by hydrogen (which then forms H20) then this would water the solution down – however, the ion exchange only removes metals (which shouldn’t be there in the first place) and they wouldn’t affect the alcohol content anyway! Perhaps this is just a result of hearsay; like she says, they haven’t specifically tested in this way, so it’s probably based on word of mouth. Some people may think that they have lost a little alcohol because some has been retained inside the filter, or else they’ve previously saturated the carbon with water and this has come out first into the collection chamber, diluting the product? That’s the best I can come up with, if anyone has any other ideas, please let me know!

So, to sum up then, the story so far : a Brita filter is made from activated carbon and ion exchange resin beads. Filtering alcohol with one of these WILL help to purify the alcohol – but only if it is contaminated with chlorine, Volatile Organic Compounds, heavy metals, or general contaminants such as dust or residue from not completely sterile storage containers or suchlike. What it will NOT do is turn a cheap vodka into a good one, but providing you change the filter regularly it will most likely contain less of those materials than the original spirit, if any were indeed present at all.

Job done then, case closed?

Not exactly. First of all, why bother using a Brita jug at all? You can buy activated carbon from any homebrew shop at a fraction of the price of replacement Brita cartridges. Yes, this means that you will have to use your initiative and make some kind of device to hold the carbon – this could be as simple as a coffee filter in a funnel, but many home distillers use a piece of sterile water piping cut to a length of maybe 3 feet, with a coffee filter at one end, held in place with a jubilee clip. The example below shows a ready made pipe for just such a purpose.

It doesn’t take a genius to work out that filtering through 3 feet of carbon is going to work better than through the small quantity in a Brita filter, and it will work out far cheaper too. The only downside is the fact that this much carbon must be prepared and saturated with water before use, otherwise it will soak up some of your alcohol and it won’t filter so effectively. As a consequence of this, the first liquid to come out of the bottom will be water and you’ll need to work out when to switch collection vessels once your spirit starts to come through.

It’s not that difficult, but I can see why people would prefer a small scale option when they’re just trying to filter one bottle rather than a full batch of distilled spirits. This is still a good option for the home distiller though, or for anyone who has a big party planned and was dreading having to sit there and run ten bottles of Tesco Value Vodka through a Brita jug – to be honest, they probably deserve all the misery they can get for buying that stuff.

TIP : Use activated carbon from your local homebrew supplier, NOT from the local aquarium store. That fishtank stuff is not food grade material, and can sometimes contaminate your spirits. It won’t kill you, but it’s not the best material for the job, and the good stuff won’t break the bank – especially not compared to Brita refill cartridges!

A second option is to introduce the carbon into the spirit itself – i.e. to take your bottle of cheap vodka, add a few spoonfuls of activated carbon, shake it thoroughly and then run through a coffee filter to remove the carbon granules. For my money, this is a better idea than using a Brita jug, as it will save you a lot of money and uses fresh carbon each time so you’ll get the maximum benefit for the minimum effort expended. If you add it a few days beforehand and shake it every now and again, it’ll work even better.

TIP : Activated carbon will filter spirits most effectively if they are in the region of 40% ABV (80% proof). Stronger spirits are not filtered as efficiently, so make sure you do your final filtering (polishing off) your spirits AFTER they have been diluted to a drinkable strength. This will also filter the water you’ve diluted with, so it’s all good!

Plastic fantastic? Far from it!

There is another good reason not to use a Brita filter for alcohol – it is made of plastic. Home distillers are almost fanatical in their hatred of plastics in any part of the distillation and storage of spirits, but why is this? Are they just being snobby or is there a genuine problem? More on this subject in an upcoming article. For now, just know that most people would say that plastic and alcohol do not mix, and that you could be risking your health if you choose to do so.

Final words

I hope that you have enjoyed reading this article, and that it has proved useful. If you have any comments or points to raise, why not stop by the forums or leave a comment below?