So I got this little 1 gallon air still, to try out this distillation thing, and I'm having a grand time. I knew going in that the air still has significant limitations, especially in volume and the amount of work that has to go in to get a small amount of product out. But I've got a couple other projects I'm committed to, before I can move to doing a larger still, which I'm absolutely planning on doing late this summer. So for now this is what I've got.

I tried to approach it from the outset, to turn that limitation into an advantage. The advantage of tiny volumes is that I can experiment with mashing, with fermentation, with flavors, work on figuring those out, and if something fails I'm not out a whole lot. 10 lb of grain and 4 gallons of water isn't much, even if I screw it up completely and have to dump it all. I haven't yet, but it relieves a lot of the pressure as I figure this stuff out.

One of my goals from the start was to try a bunch of different single grains, and effectively make a series of flavor exemplars, so I can see what they do each of them to the flavor of whiskey. My first batch was 100% distillers malt, and my second batch was 80% grain barley with enough distillers malt for conversion. Both of those, kind of as expected, give me a pretty clean neutral grain flavor, kind of indistinguishable from each other. The third batch I'm doing now is 100% pale ale malt, and I'm getting a lot of flavors out that I can find even during my stripping run, that I never saw during either of the previous. I'm going to be trying to bunch of different malt roasts and varieties going forward, then also try oats, wheat, rye, and maybe even some corn at some point.

So for what I'm doing, this is useful, and I'm having fun. But I figured some things out about using an air still, that might be useful to others. A lot of these things were suggested from reading elsewhere, that I don't remember where, but I'm mostly standing on shoulders here, not actually reinventing the wheel.

I'm using the classic air still, not the air still pro with the reflux function. All of this is relevant to a little 1 gallon air still in pot still mode.

1. Put a copper mesh in the base of the boiler, to function as a 'boiling stone.' I took a copper scrubby, cut out the little solder spot that holds it together, and then unrolled it into just a flat mesh that loosely fits the bottom of the boiler. The idea is that it creates spots for boiling bubbles to start, and keeps them from bumping in large bubbles to the surface.

My first three stripping runs I didn't do this, and all three of them puked a little bit. Once I added copper mesh across the bottom, I haven't had a stripping run puke yet, using the same volume. Also it gets a significant amount of copper in the boiling wash, for copper catalysis of esters, and removing sulfites. All the experts and all my knowledge of chemistry says these are good things.

1. Get the little basket that fits in the head, and fill it with copper scrubbies. That little basket is hideously expensive, about $20-25 for a 5-in diameter screen, but it allows me to get a significant amount of copper in the vapor stream. I have three copper scrubbies, again with a little solder spot cut out, kind of pulled apart and then reformed so it fills the basket pretty efficiently.

2. De-gas, and throw in a little bit of oil. I use a whisk, once I filled the boiler 3/4 full on my stripping run, and whisk the bejeebers out of it until fizz stops coming out. And I'm using a little dollop of coconut oil to break surface tension and 'boiling over.' This is relevant to any still, but I've discovered it's easy to forget if I don't specifically write it in my procedure and checklist.

3. Remove the little square collection funnel that snaps onto the outlet. This might be specific to the air still classic and not the new pro head, I don't know if that has a little collection funnel. The problem is that when product comes off the coil instead of dripping directly to my collection glass, it drips into this little collection funnel, where it sticks and pools and causes smearing. When I took it off after a few runs, I could smell both heads and tails in there, a while after my last stripping run. That has to be causing significant smearing, that I think especially is pulling tails into the entire run. It works just fine dripping straight out of the head, and not using that little square funnel. And I'm convinced on currently inadequate data that it's giving me much sharper transitions between hearts and tails.

4. Get a router/motor controller, and a computer / monitor cord.

The US air still runs on 110 volts with a nominal 740 watt heater, which I'm told actually puts out about 700 watts. This works fine for stripping runs, maybe even a little wimpy as it gets laid into the run. But for spirit runs it's too much power, it runs too fast, and everything smears into everything. My first spirit run at full power, I couldn't find hearts. It seemed like my heads ran directly into tails.

You can unplug the head from the boiler body, plug it into a computer / monitor cord, and plug that directly into the wall. The fan will run at full power.

I bought a VivoSun "fan speed controller", and I plug the air still pot into that, and that into the wall. Use it for spirit runs, set it on full speed to heat the pot, and then turn it way way down as soon as the first drops come over, to substantially cut the amount of heat going into your wash, and slow the distillation way down.

The VivoSun unit has three sectors, hi, medium, low. I found that when the first drops come over running at full power, I can turn it to variable mode and turn it all the way down to the middle of the low power sector, to get below one drop per second, and a collection rate of about 50 ml every 10 minutes.

This has to be tended and turned up throughout the spirit run, to keep the still working at the same rate. I just collect in jars pre-marked at 50 ml, and time how long it takes to change a jar, to tell me whether I need to turn the controller up or down.

I haven't yet determined what the actual power consumption is on that setting, but I have a power monitor out in the workshop, which I'm going to pull in at some point and check. When I do, I'll post the results here.

This was extraordinarily better than running it without a controller. This is probably the single most important thing you can do to the air still to make it work better.

From my next run I'm going to go even slower, turning it down to about 35-40 ml every 10 minutes, and see if I can clean up the heads, hearts, tails transitions even more.

Having done several spirit runs now, including running my first couple batches a couple times with the faints thrown back in to redo my cuts, it's almost magical how much better this thing performs with the motor controller and turning it way down.

-- So that's what I figured out so far. Might be useful to some people, and I am extremely open to additional suggestions or criticisms.