A QUESTION I’m often asked is about the importance of carbon filtration in the distilling process, so I found an article which covers it pretty well.
The short answer is, if you’re using turbo yeasts, you’ll need it; if you’re using Global Express Fast & Clean distillers yeast, you don’t need to.
Turbo yeasts are garbage… and they need extra processing because of their impurities, after a wash has completed.
They need this extra processing to get them even close to drinkable.
Global Express Fast & Clean is the only yeast worldwide that has been specifically bred for sugar washes.
About Carbon Filtration
Turbo Carbon – Specifically designed for use during fermentation. It absorbs impurities as they are being formed by yeast in the wash.
This is then dropped to the bottom with the yeast after the addition of turbo clear, vastly reducing the impurity level going into the boiler and increasing the efficiency of your filter carbon for a purer, cleaner and smoother spirit.
NOT ALL CARBON WORKS ON SPIRIT – there are only a few grades of carbon which are suitable for filtering spirit washes or finished spirit.
Water filter carbon doesn’t do the job – at all.
The size and number as well as the structure of the pores, Meso, Macro and Micro pores as well as the craggy structures around those pores will determine whether a carbon is effective in removing the impurities found in alcohol.
You won’t get ANY improvement by filtering through the carbon used in water treatment or most of the other commonly available types. Use the right stuff.
There is something you can do at each stage to reduce the load on your carbon. Most commonly this is caused by turbo yeasts, inferior brewing sugars and failing to clear your wash prior to distilling.
KNOWING THE LIMITS: There’s a limit to what carbon can do to improve spirit quality.
Pushing the run too far (trying to collect too much) and too fast and you are ringing the neck of the beast and collecting additional unwanted fusels.
Always remember that towards the end of the run, unwanted fusels also test as alcohol, so don’t push your run too far.
IMPORTANT NOTE: Distilling at home isn’t entirely about finding the cheapest way possible to collect the largest quantity possible. For most, it’s about having pride in quality and thus quantity becomes a secondary consideration. Once you grasp the following few points, it’ll make a lot more sense:
A spirit wash, regardless of it’s composition, is only capable of producing around 1 to1.1litre of spirit at 40% for each kilogram of fermentable sugar whether it be Dextrose, Cane Sugar, Castor Sugar or anything else.
Everything beyond that magic 1.1 Litre/kg mark detracts from the purity of what is collected.
If you collect say, for instance, 4 litres of spirit at 80% purity from a 6kg batch of ANY sugar, then you’ll effectively end up with 8 Litres of 40%… way beyond what is recommended.
Just because a dumb float (Alcoholmeter) says it’s 40% Alcohol, doesn’t mean it’s 40% ethanol. Your batch will have quite a large amount of other poor quality alcohols making up the rest of that volume. Some of these aren’t exactly good for you over the long term.
A word on alcometers. Alcometers (alcoholmeters) are manufactured to exacting specifications and are designed to measure ethanol at a set temperature at sea level.
Look at the side of your alcometer and it will have a temperature stamp on it. This is the only temperature that your meter will be accurate at.
Other things also affect how it reads… like altitude above sea level and even atmospheric pressure.
We can’t cover everything here, but we can make the biggest adjustment to get the most accurate reading possible – when you’re trying to read the alcohol percentage get the spirit to the correct temperature by adjusting the measurement sample in either a fridge or by warming with your hands until it’s at the calibration temperature of 20°C.
Dilute before filtering – Water down to 50% or less (40% is best) before carbon treatment.
The reason for doing this is that unwanted flavour compounds are dissolved by high strength alcohol and are difficult for the carbon to remove over 50%. If you water down to 40% first you save the later step, to dilute to final 40% ABV.
Mineral Salts – Mineral salts are present in the raw materials used to make activated carbon.
When spirit runs over activated carbon, mineral salts can be absorbed into the spirit. Later these minerals start to become insoluble in the spirit and after a few days forms a fine haze which eventually drops to the bottom of the bottle as sediment.
These mineral salts are 100% safe but you don’t want them in your spirit.
This is why we recommend flushing the carbon with clean water (4-5 Litres of water per 100g of carbon) prior to adding to your spirit. If you notice this effect in your spirit you can decant it off after it settles.
As a rule, you will get better filtration through carbon which has been thoroughly wet with water first
Reusing Carbon – Don’t! Carbon can only be used once.
A used batch of carbon contains all the junk you took out of the previous batch. Carbon works by micropore absorption, once these sites have been filled, contaminates will pass straight through to poison you!
To reactivate carbon simply isn’t worth it. It requires that you heat it to 500°C in an anoxic (oxygen added at this stage would cause an explosion) environment (such as an autoclave) and injecting with steam.
Even if you could do this at home it is still cheaper to use a new batch!
Soaking / Polishing – Often used as a pre-treatment for filtering and, used this way, produces a very good result.
Use this process if you have plenty of time on your hands – it’s rather inefficient if not done properly, but can be effective, especially when used in conjunction with normal filtering.
The process of polishing your spirit is done by applying 10g of high activity carbon per litre of spirit in a vessel of suitable size.
It’s then agitated several times a day for 2 days. It’s then agitated daily/twice daily for the next 2 weeks.
The correct carbon to use for polishing is commonly known as “High Activity Carbon”. It’s an acid washed carbon in the activation process and should be first washed thoroughly, then soaked in clean water (1 litre per 100 g of carbon is sufficient) for 24 hours before use in spirits.
Double filtering? – A single pass through the filter should be enough to remove all odours and tastes from a batch of your spirit. If it is still present review your process and ingredients.
Or dump your turbo yeast and go with Global Express Fast & Clean!
Until next time… Happy Distilling!