IN OUR 13th Beginner's Gems for Home Distillers, we take a look at Carbon Filtering.
Our previous Beginners’ Gems posts containing helpful hints, tips and techniques for home distillers, include the following:
- Beginners’ Gems #1: Basic Knowledge to Help Home Distiller Beginners
- Beginners’ Gems #2: More Basics to Help Home Distiller Beginners
- BEGINNERS’ GEMS #3: The Finer Points of Fermentation Temperature
- BEGINNERS’ GEMS #4: Solutions for Fermentation Problems
- BEGINNERS’ GEMS #5: Even More Solutions for Fermentation Problems
- BEGINNERS’ GEMS #6: Finally Taming the Yeast Beast
Do we really need it? Depends on the quality of your yeast!
How does carbon cartridge filtering work?
Good quality carbon filters use a specially formulated solid activated carbon cartridge to remove unwanted flavours from distilled alcohol.
The cartridge’s porous design allows the spirit to pass through and the unwanted flavours to be absorbed by the activated carbon.
The cartridge eliminates the need to handle powdered or granulated carbons.
How do I accurately water my spirit down to 40% before filtering?
Using a test tube float a Spirit Hydrometer in a sample of the distillate that spirit to measure the alcohol content.
Alcohol is thinner than water so the higher in strength the alcohol is, the further down the hydrometer floats.
Read the line where the level of the spirit cuts across the hydrometer, this is your alcohol %. Additives such as flavouring will distort the hydrometer readings.
Spirit hydrometers should only be used to test spirit at the calibrated temperature.
Spirit Hydrometers are calibrated at a temperature of 20°C (68°F) if the spirit is a different temperature to this then you'll need to refer to a Temperature Correction Chart.
How does activated Carbon work? How does it help purify alcohol?
Activated carbon is are prepared in a manner which causes the carbon crystals to become porous and develop a very large surface area.
One gram of activated carbon may have 500 – 1500 square meters of internal surface area. This large surface area and the many internal pores in the carbon are able to absorb many different chemical compounds including those which cause unwanted flavours in your spirit.
The absorption process is very complex and depends on concentrations, molecular weight etc.
In the case of alcoholic spirit the process works best if the alcohol concentration is 50% or less. This is why we recommend adjusting the alcohol level before purification.
Do I need to flush my carbon with water before running spirit through it?
Mineral salts are present in the ingredients used for manufacturing activated carbon.
If these are not flushed out they can be absorbed into the spirit.
Later these salts can become insoluble in the spirit, especially at lower temperatures, and can form a fine sediment or haze.
Until next time... Happy Distilling!