Spirit Cloudiness --- A Quick Effective Fix
Posted: Thu Dec 07, 2017 7:31 pm
The following is a description of how I cleared my white spirit of the watering-down cloudiness; technically, emulsification, or sapponification. The answer is plain facial tissues, Kleenex, snot rags, etc; unscented and of course unused. White coffee papers should work well too. Carbon granules are good at removing off smells and flavors, but do not reduce the haze. As shown below, there is no need to treat cloudiness when the final product is aged with oak chips. It is necessary when making say gin or other clear botanicals. These methods clear the haze at room temperature, although my G&Ts do stay clear even when icy cold.
The haze is caused by a small amount of yeast lipids (mostly triglycerides), fatty acids, and sterol-esters transferring from wash to distillate. These are only created in the wash, but other undesirable products such as acetates and simple esters can appear after distillation. The fats are fully dissolved in 60% alcohol but will start to accumulate in microscopic droplets (micelles) as the alcohol is reduced to 45% and lower. This is emulsification, which appears as a mild but annoying haze. If enough hydroxls are present the droplets may be converted to soap (sapponification) and the spirit will look like milk.
My white spirit, produced by double runs with a pot still, always developed an undesirable level of cloudiness after watering down to 40%. No matter what precautions taken the haze always came back, taking up to 2 days to fully develop. (Note that bicarb alone does not prevent haze.) Most of the spirit goes into making whisky, using toasted oak chips, but I also make gin and triple sec. The gin and sec always stay cloudy, but the whisky magically clears no more than 48 hours after adding the oak chips. I figured that the hardwood chips are fine grained and have very small capillary tubes that attract and store the lipids. I have a mounting pile of used oak and it seems a shame to throw the lot away.
Starting with 2-liters of hazy 40% spirit, I added 6g of depleted French oak which had been soaked for 3 weeks, and then soaked in hot clean water. The haze was gone in 24rs but there was a feint color and taste of burnt whisky. After the second distillation run the whisky aroma was just discernible, and carbon granules did no clear it. Mild botanicals like triple sec (triple distilled) and pear schnapps demand a very clean spirit.
Facial tissues are usually made from pulped and bleached hardwood, and also white coffee papers. (Australian tissues and toilet paper are made from 2000 year old Tasmanian hardwood forest trees, so should be perfect.) I added one tissue to 600ml of very cloudy gin. The gin was fully cleared within 24hrs. Even better, the gin flavor and aroma was not discernibly affected. In a further test, two tissues were added to 4L of cloudy spirit and it cleared after 2 days.
Adding gin essence to cleared spirit does add a tiny bit of haze, but nothing as cloudy as emulsification. A half tissue was very effective at removing the gin botanical haze from a 1L bottle without affecting the flavor at all. The tissues can be filtered out of the spirit by passing it through a funnel with a small tuft of cotton wool in the neck. Bleached coffee papers are tougher and may be removed with tweezers, and squeezed dry. Coffee papers can be used to filter particles, and a ribbed funnel is essential.
Cotton wool, while also cellulose, does not have the tiny capillary tubes of hardwoods, and it had no effect on cloudiness. Cotton wool is very good for filtering out tiny particles though; the continuous roll or ripple types work well. Pinch off a piece larger that the funnel neck and put it at the bottom, but not pushed in tightly. Run th alcohol through the funnel.
The bicarbonate of soda treatment, mentioned in the HD Stripping article, is very effective at converting ethyl acetate in the wash. Straight sugar washes will typically have up to 500ppm of this chemical which has a very low taste and smell threshold ... like acetone but stronger. The article recommends adding bicarbonate of soda to the distillate to convert the highly objectionable ethyl acetate. Acetates and simple esters mixed with water can sometimes produce a haze, but it's temperature dependent.
After some experimentation I found nearly all the acetate mass originates in the wash. Adding a modest amount of sodium bicarbonate (3g/L) to the finished wash 2 days prior to distilling is very effective at cleaning up the pesky acetate. Adding 1 or 2 desert spoons of dissolved bentonite to the wash also helps to clear yeast products, although it's less effective here than when it's used in wine. Needs stirring thrice in 24hrs. Setting the pH near neutral also inhibits further ester production.
--Summary--
My experimentation is not yet done. Presently I do the following to clear the haze:
1. Add bicarb and bentonite to the wash and stir 3x before distilling.
2. Do a stripping run to get 58% spirit. Optionally, soak one tissue per 2L overnight. If the pH is lower than 6.5, add a bit of bicarb, 1-2g/L.
Prevents new acetates forming. Untreated, the first run often has a pH of 5.5.
3. Do a second distillation run to produce 73% spirit.
4. Water down to 40% and add 1 or 2 tissues per 3L, and a pinch of carbon granules. Leave a week or so. Watering down should be done
first as it allows the max amount of lipids/fats to be removed.
The haze is caused by a small amount of yeast lipids (mostly triglycerides), fatty acids, and sterol-esters transferring from wash to distillate. These are only created in the wash, but other undesirable products such as acetates and simple esters can appear after distillation. The fats are fully dissolved in 60% alcohol but will start to accumulate in microscopic droplets (micelles) as the alcohol is reduced to 45% and lower. This is emulsification, which appears as a mild but annoying haze. If enough hydroxls are present the droplets may be converted to soap (sapponification) and the spirit will look like milk.
My white spirit, produced by double runs with a pot still, always developed an undesirable level of cloudiness after watering down to 40%. No matter what precautions taken the haze always came back, taking up to 2 days to fully develop. (Note that bicarb alone does not prevent haze.) Most of the spirit goes into making whisky, using toasted oak chips, but I also make gin and triple sec. The gin and sec always stay cloudy, but the whisky magically clears no more than 48 hours after adding the oak chips. I figured that the hardwood chips are fine grained and have very small capillary tubes that attract and store the lipids. I have a mounting pile of used oak and it seems a shame to throw the lot away.
Starting with 2-liters of hazy 40% spirit, I added 6g of depleted French oak which had been soaked for 3 weeks, and then soaked in hot clean water. The haze was gone in 24rs but there was a feint color and taste of burnt whisky. After the second distillation run the whisky aroma was just discernible, and carbon granules did no clear it. Mild botanicals like triple sec (triple distilled) and pear schnapps demand a very clean spirit.
Facial tissues are usually made from pulped and bleached hardwood, and also white coffee papers. (Australian tissues and toilet paper are made from 2000 year old Tasmanian hardwood forest trees, so should be perfect.) I added one tissue to 600ml of very cloudy gin. The gin was fully cleared within 24hrs. Even better, the gin flavor and aroma was not discernibly affected. In a further test, two tissues were added to 4L of cloudy spirit and it cleared after 2 days.
Adding gin essence to cleared spirit does add a tiny bit of haze, but nothing as cloudy as emulsification. A half tissue was very effective at removing the gin botanical haze from a 1L bottle without affecting the flavor at all. The tissues can be filtered out of the spirit by passing it through a funnel with a small tuft of cotton wool in the neck. Bleached coffee papers are tougher and may be removed with tweezers, and squeezed dry. Coffee papers can be used to filter particles, and a ribbed funnel is essential.
Cotton wool, while also cellulose, does not have the tiny capillary tubes of hardwoods, and it had no effect on cloudiness. Cotton wool is very good for filtering out tiny particles though; the continuous roll or ripple types work well. Pinch off a piece larger that the funnel neck and put it at the bottom, but not pushed in tightly. Run th alcohol through the funnel.
The bicarbonate of soda treatment, mentioned in the HD Stripping article, is very effective at converting ethyl acetate in the wash. Straight sugar washes will typically have up to 500ppm of this chemical which has a very low taste and smell threshold ... like acetone but stronger. The article recommends adding bicarbonate of soda to the distillate to convert the highly objectionable ethyl acetate. Acetates and simple esters mixed with water can sometimes produce a haze, but it's temperature dependent.
After some experimentation I found nearly all the acetate mass originates in the wash. Adding a modest amount of sodium bicarbonate (3g/L) to the finished wash 2 days prior to distilling is very effective at cleaning up the pesky acetate. Adding 1 or 2 desert spoons of dissolved bentonite to the wash also helps to clear yeast products, although it's less effective here than when it's used in wine. Needs stirring thrice in 24hrs. Setting the pH near neutral also inhibits further ester production.
--Summary--
My experimentation is not yet done. Presently I do the following to clear the haze:
1. Add bicarb and bentonite to the wash and stir 3x before distilling.
2. Do a stripping run to get 58% spirit. Optionally, soak one tissue per 2L overnight. If the pH is lower than 6.5, add a bit of bicarb, 1-2g/L.
Prevents new acetates forming. Untreated, the first run often has a pH of 5.5.
3. Do a second distillation run to produce 73% spirit.
4. Water down to 40% and add 1 or 2 tissues per 3L, and a pinch of carbon granules. Leave a week or so. Watering down should be done
first as it allows the max amount of lipids/fats to be removed.