Faster production, less smearing? How does that work?

If you have read the Blog posts of the last few weeks, for sure you noticed we have been able to beef up performance quite a bit. But putting in more energy, creating a harder boil, increasing vapour speeds … doesn’t that result in more smearing? More heads and tails getting over into your hearts faction?

No, it does not. Not in Pure Mode at least.

A potstill will smear more when more power is applied. And so will the iStill in Potstill Mode. Potstilling is easy. You bring a liquid to a boil, gasses rise up and are cooled down to liquids in the condensor part of the still. Lighter alcohols boil off in bigger quantities during the early parts of the run (heads), heavier alcohols (tails) in the later parts of the run. Hearts are in the middle. But if you push the tempo, put more energy in, heads and hearts and tails will come over all the time. More energy in means more vapour is being created. And since column diameter is the same, vapour speeds will get higher and higher, allowing for (for instance) the heavier tailsy molecules to come over in hearts, and resulting in a bad product.

But in Pure Mode, or at least in an iStill in Pure Mode, things are quite different. As an example, let’s say we produce hearts at a power input of 9 KW. Pretty much the standard setting. And pretty impressive with a return of close to 14 liters per hour on a 16% boiler charge. In Pure Mode not all liquids are taken as product. Contrary to the Potstill Mode, a part of the liquids is returned down the column for further re-distillation. That way you can collect at 96% all the time. The computer simply calculates how much reflux is needed and takes it from there.

Now, let’s dive in and see what happens when we dial up power input during a Pure run. Say 12 KW. Just as in the Potstill Mode more gasses are created and vapour speed increases. More vapour is being cooled down to liquids and part of the liquids are sent back down the column (AKA reflux). More energy = more vapour = more reflux. And the more reflux is returned down the column, the more efficient the column packing will work, giving better control over heads and tails, giving you more re-distillations, a more stable run, and faster production with less smearing. In Pure Mode more power input means more plates, and more plates mean more control and faster production.


2 thoughts on “Faster production, less smearing? How does that work?

  1. Odin, with every blog post you make these days, I absolutely feel that I have made the correct choice in the iStill 250. Keep up the good work. Cheers.

  2. Odin,

    We’re psyched about our new iStill 250! Cape May Distillery had been in the planning and development phase for 2 years and this year we received our DSP and state licenses. We’re the first licensed craft distillery in New Jersey since Prohibition. Cape May, NJ has a rich maritime heritage and our spirits will be a reflection of that history. We’ll begin with the production of light, barrel aged and spiced rums and progress into whiskey and bourbon, gin and vodka.

    The iStill is exactly what we were looking for and we believe it will serve us well. We first heard about it from our friends at ADI so we started researching it. When we heard there would be one auctioned off at the ADI Conference in Seattle, WA, my partner and I decided that we weren’t coming home without it. So now we’re the proud new owners of the iStill 250 and can’t wait for our first run.

    Hats off to you and Bill Owens and his team at ADI!

    Lee Phillips
    CMY Distillery

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