Air Still

[Freakosystem]

Does anybody here have experience using an air still to distill alcohol for plant extracts, tinctures or essential oils? I understand the limitations of these kits are that they're only capable of distilling small amounts which aren't considered particularly practical for producing spirits for consumption but the smaller amounts needed for tinctures seem to make this a worthwhile thing, particularly given how difficult it is to otherwise obtain high proof without methanol contaminants.

 

Anybody ventured down this road?

[fyzygy]

Off-topic but maybe still relevant, the manufacturer of "bubble bags" claims they can be used to extract essences from almost any plant material, using nothing but ice-water, agitation and serial filtration. 

[fyzygy]

Technically, you'd need a licence (in Australia, but not New Zealand) to produce even the limited quantities of pure alcohol you require?

 

[mr b.caapi]

From what i hear air stills produce quite low quality alcohol. I have a Turbo 500 reflux and I get around 94% of smooth spirit.  Very easy to use.

[Ricardo]

I do have experience with the air still. The air still will produce an end result of around 60% ABV. Traditionally you collect the first 700-800ml after which the quality of the product drops off very quickly. You then water it down to 1 - 1.25 litre at 40% abv.

They are designed to not produce methanol at the start so seperating heads, body and tails is not necessary with the air still. Although for your purposes the "heads" of the process will be a much higher percentage ABV... Probably in the 90s. I couldn't tell you the volume you would get at that ABV though, my guess would be maybe 100ml, but that really is just a guess and would have to be experimented with.

The way a still works for alcohol is based on the fact that alcohol boils and evaporates at a lower temperature than water. 80°c for ethanol and 100°c for water. So as the still heats up the ethanol evaporates and comes out first (along with some methanol, but not in the air still). 

The other thing is, based on preference but very much suggested, is that the alcohol then needs to be filtered through charcoal. The air still comes with a kit to do this but the kit only works for alcohol at 40% or below. 

The answer in the end is that the air still can be used for your purposes but it isn't the ideal product for it. I get that it is half the price of a bigger, better still but if very high ABV alcohol for tinctures is all you want you should probably get a real still.

      The air still is basically the "distilling for dummies" tool, which isn't to knock it because it is actually a good product. But it's really only made for one thing and that is to make a 40% ABV neutral spirit. Getting anything else out of it will be going against the recommendations of what it is for and is up to you. 

If you do decide it is what you want to use then here are the tips I will give you.

Use turbo yeast packets, they are the best for your purposes and also contain nutrients for the yeast. 

Use 100% dextrose if you can. It produces a much smoother end result than other sugars and is 100% fermentable meaning if all goes right it will be totally gone at the end of fermentation and no lingering bits will hang around effecting the taste. Other sugars don't completely disappear like dextrose does. Although if you want to save money and don't care as much about any of that, then just bags of sugar from Coles work too.

Add liquid charcoal to your fermenter. It will keep the fermentation process from getting contaminated and is easy enough to remove at the end of the process when you add your clearing agents.

Degas the brew thoroughly before distilling. Think of how fizzy a bottle of coke is, that is about as carbonated as your brew is going to be. The goal is basically to make that bottle of coke go flat. People stir the crap out of it for as long as they can to get all the bubbles out, this process is a pain in the ass. I prefer to put a second fermenter under the other one and turn the tap so it all comes pouring out from one into the other. As the brew lands in the second container it will de-gas little by little. Just repeat the process over and over. It will take just as long but is easier than stirring with a stick.

You can get away with not completely getting every last bubble out when it comes to the air still. But it is dangerous to try and distil carbonated brew in any still. There are little ceramic things you throw in the bottom of the still which help break up any bubbles and "distilling conditioner" that will do the same. These are what make it not so bad to half ass the degassing a touch. I still wouldn't recommend it though, bubbles can lead to booms.

You will read the instructions to the still anyway so I am not going to go through every step. Just remember when you turn it off at the end DO NOT open it straight up. Leave it for a full day to cool down and it really will take that long. This slows down the process a fair bit since it takes 4 litres at a time so you have to 5-6 runs for one 23 litre fermenter worth (other stills will do the whole thing in one run). But don't risk opening it up early, severe burns can happen.

Apart from that, the thing is pretty safe to use compared to other stills. It has an automatic killswitch that prevents it from running while dry. And the top of it provides enough of a seal to do the job, but not enough to create a bomb. Plus there is no flames needed which can be dodgy around alcohol vapours.

But yeah dude, that is all I can think to add on the air still, ask if you want to know anything specific.

[Ishmael Fleishman]

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Edited August 16 by Ishmael Fleishman