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Feb 17, 2021
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I recently read a thread regarding freeze distillation. It was a 2012 thread, old , yeah, but I couldn't help but find the thread very humorous. Not an attorney, but it reminded me of watching Senate hearings, they squabble over wording and definitions constantly. Anyway, the thread argued the difference between distilling, reducing, and concentrating. The concept, as I see it is to improve the quality and ABV that we desire in our beverage pursuits. Correct me if I'm wrong, but doesn't that simply mean seperating water from the targeted solution that we desire. In other words, dehydrating the beverage at hand. The outcome is not the intent to create liqour, which requires a license, and there are no laws written that addresses dehydration. So, I will introduce an alternative process that is 100% legal by the ATF, TTB, and LCB, it employs the use of molecular seives. These little sweethearts soak up water in most any liquid solution leaving behind the rest. This does not change any of the properties of the solution other than removing the smallest molecules of liquid, H2O. Check it out. It works well for me. I have fortified many batches of wine and beer in this process. It's still beer and wine, just better.

I now see how it can be done. The water molecules pass through, the other molecules do not.

Not a real alternative to distillation if you get all alcohol fractions in your final product. An alternative to distillation if you can selectively filter certain molecules and get rid of "fusel oils", or "head fractions".

This would be very interesting for distillers, especially in the quest to obtain the perfect "neutral", keeping only ethanol and leaving behind all the rest. It is worth investigating and discussing for sure.
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Granted molecular sieves do not necessarily remove alcohol fractions.
Molecular sieve, a porous solid, usually a synthetic or a natural zeolite, that separates particles of molecular dimension. Zeolites are hydrated metal aluminosilicate compounds with well-defined crystalline structures. The silicate and aluminate groupings form three-dimensional crystal lattices surrounding cavities in which the metal ions and the water molecules are loosely held. Channels run through the entire crystal, interconnecting the cavities and terminating at the crystal surface. Upon heating, the zeolites lose their water content with little or no change in their crystal structure. The dehydrated zeolite can reversibly absorb water or other molecules that are small enough to pass through the channels or pores. The metal ions are also readily replaceable by other ionic units of similar charge and size.
Molecular sieves are used for drying gases and liquids and for separating molecules on the basis of their sizes and shapes. When two molecules are equally small and can enter the pores, separation is based on the polarity (charge separation) of the molecule, the more polar molecule being preferentially adsorbed. Water is a "polar" molecule, meaning that there is an uneven distribution of electron density. Water has a partial negative charge ( ) near the oxygen atom due the unshared pairs of electrons, and partial positive charges ( ) near the hydrogen atoms. Furthermore, An ethanol molecule is about 4 × 10-8 m across, while a water molecule is only 1.7 × 10-8 m across.
Yes Fusel's are a problem I have yet to rectify completely. However, in regard to the thread I had mentioned addressing freeze distillation/reducing/concentrating to produce a higher ABV, the Fusel's are there even without distillation. Fusel alcohols are higher order (more than two carbons) alcohols formed by fermentation and present in cider, mead, beer, wine, and spirits to varying degrees. Excessive concentrations of these fractions can cause off flavors, sometimes described as "spicy," "hot," or "solvent-like." Some beverages, such as whiskey, Siwucha and traditional ales and ciders, are expected to have relatively high concentrations of fusel alcohols as part of the flavor profile. Here we can see that fusel's are not always the bad guy. But in other beverages, such as vodka and lagers, notable presence of fusel alcohols is considered a fault. Very high concentrations - usually caused by incompetent distillation or improper fermentation - can cause illness, including headaches, nausea, vomiting, clinical depression, or coma. Such a liquor may be referred to as rot-gut or rotgut. Fusel alcohols are formed when fermentation occurs: at higher temperatures ( when ethanol combines with esters, fusel alcohols in beer are formed. These are the longer chain alcohols that get produced when fermenting at higher temperatures, therefore fermenting at a lower temperature for a longer period of time will form less Fusel Oils), at lower pH, and when yeast activity is limited by low nitrogen content. There are ways to address this: ferment at the lower end of the temperature range for the yeast selected, switch yeast if lower temperatures still produce unacceptable levels of “hot” fusel alcohols, examine your nutrient additions and oxygenation procedures to make sure the yeast are happy and health, sometimes it is best to introduce some extra sugar later on in the fermentation. This is called Chaptalization. When adding Belgian Candi sugar to your stronger Belgian ales, some homebrewers recommend adding it a few days into the fermentation so the yeast are past the lag phase and hard at work. Too much sugar in the wort can stress the yeast and make it difficult for them to uptake the nutrients they need to multiply and form strong cell walls. It is always best to baby your high alcohol beers through the fermentation with plenty of attention to temperature, nutrients, and oxygen. The actual makeup of fusel oil depends principally on the ingredients of the fermentation, the fermentation temperature, and to a lesser extent the Fermentation variables like pH and Nutrients. The addition of ammonium salts to a Fermentation reduces the formation of fusel oil. Although, Fusel oil is the aroma of the mash. As opposed to the fermentation process, during distillation, fusel alcohols are concentrated in the "tails" at the end of the distillation run. They have an oily consistency, which is noticeable to the distiller, hence the other name fusel oil. A high percentage of Fusel oils can lead to Chill Haze or louching. This is typical of several styles of spirits, including Ouzo and Absinthe. Here I am not suggesting this as an alternative to a quest for the perfect "neutral" , but more an alternative to breaking the law to obtain a fortified solution.
As for the head fractions, this is very simple. After fermentation heat the wort to 169 F/77 C, hold it at temp for 10-15 minutes and the heads will remove themselves. Then cut the heat and cool quickly if possible. You will be surprised at the clarity your flavors will retain, and the removal of methanol/heads seriously benefits your outcome.

I see, but that greatly reduces my interest for this method of water elimination.
In fact, a good old still is very effective in reducing water content while maintaining the rest in the brew. But a distiller can also help reducing water content while discharging head fractions and tail fractions. A molecular sieve doesn't do that and in that sense is a very "primitive", even though modern, way of reducing water content.

Those alcohol fractions are certainly present in the original fermentation, but they become more and more evident (and nasty) once their concentration raises due to the elimination of the water.
Eliminating the water without reducing the head and tail components is a headache-prone way of distilling. In fact, nobody does that with a still.

My concern is that a "fortification" (rectius a distillation) with molecular sieves might bring to undesirable results. This is probably also true of other distillation method such as freezing the water content. One has to keep this into consideration and, as you say, maybe control the head and tail fractions more strictly in the original fermentation.

For the sake of precision, even though it is commonplace to consider ethanol as a head fraction, in fact it tends to be present throughout the entire distillation run. Methanol is not really a problem flavour-wise because it is very slightly flavoured, like ethanol. From a health point-of-view, methanol is to be kept under control only in fruit-based fermentations (apple and pear especially). In other fermentations it is present in very low quantities and not a problem. A beer producer (and a whisky producer) needs not care about methanol. Other nasty fractions, yes.

I agree head fractions can get rid of by heat or even by simple "aging" of the spirit. Head fractions will be more volatile than the rest of the brewage and will escape the brewage faster than the other fractions.

As I say: "angels must have headache" :)
Just curious: how much does such filtration cost; how much H2O can it remove from a gallon of wash or mash and how long does it take to do that?
Molecular sieve desiccants have a very strong affinity and a high adsorptive capacity for water. At 25°C/10%RH, molecular sieves can adsorb water to approximately 14% of their own weight. Prices do vary from sources and range from $20 -$30 for 5 lbs. The best thing about the is that they can be reused. Instructions for drying them and reusing came with my purchase as well ass how to activate and apply them. If you have large batches to deal with you could run them multiple times to reach your desired filtration/dehydration.
Molecular sieve - Wikipedia

As listed under applications:
FDA approval[edit]
The U.S. FDA has as of April 1, 2012 approved sodium aluminosilicate for direct contact with consumable items under 21 CFR 182.2727.[10] Prior to this approval Europe had used molecular sieves with pharmaceuticals and independent testing suggested that molecular sieves meet all government requirements but the industry had been unwilling to fund the expensive testing required for government approval.[11]

Methods for regeneration of molecular sieves include pressure change (as in oxygen concentrators), heating and purging with a carrier gas (as when used in ethanol dehydration), or heating under high vacuum. Regeneration temperatures range from 175 °C to 315 °C depending on molecular sieve type.[12] In contrast, silica gel can be regenerated by heating it in a regular oven to 120 °C (250 °F) for two hours. However, some types of silica gel will "pop" when exposed to enough water. This is caused by breakage of the silica spheres when contacting the water.[13]
The easiest way that I know of to bypass distillation is to add table salt. NaCl is insoluble in alcohol and is hydrophilic (it attracts and bonds with water). Adding in a (fairly large) amount of table salt (you should have a little more than is soluble in the water after shaking well for a few minutes evidenced by salt granules on the bottom).

Let it sit and the much lighter alcohol will float to the top and the saltwater sinks to the bottom. Decant off the floating alcohol... Same can be done with methanol and isopropyl alcohol to concentrate them as well.

This will render a higher alcohol content than freezing or distilling can. The commercial ethanol fuel industry uses rock salt to dry their product, don't use rock salt or it will take a ton of rock salt and the process will take forever.
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