Testing the pot still functionality

The iStill 50 also has a pot distillation program. I tested it yesterday and here are some first results. I will be throwing a lot of dry numbers at you, but in the end there will be an summary and a conclusion.

What went in?

The wash I used was about 38 liters of 10% ABV made out of wheat and rye. I added 2 liters of around 95% feints (heads & tails from a previous Pure Whiskey run). I used 0.25 litre glasses to collect what came of the still.

How did the run go?

10h15: Started heating up the iStill 50;

11h10: Fores were automatically drained, column stabilization started;

11h25: Column stabilization complete, temp_in 81.1 degrees C, temp_up 78.0 degrees C;

This means heads are stacked very well. Just as in fractionating mode. Pretty much the whole column is filled with ethanol with lower boiling point alcohols at the top. This allows for very compact head cuts and gives you a very fast first part of the run. First glasses filled up so fast, I could hardly keep up with the pace.

First glass came out at temp_up 78 degrees C;

Second glass came out at temp_up 85 C;

Third glass came out at temp_up a bit under 91 C;

Fourth glass came out at temp_in of 91.8 C and temp_up at 91 C;

First litre (glasses 1 to 4) was collected in just 7 minutes. That’s like 8.5 litres per hour. Darn fast.

Glasses 5 to 8 took 11 minutes to collect. A bit over 5 litres per hour. Temperature at the bottom of the column started around 91.8 C and slowly rised to 92.2 C. Temperature just under take-off started at 91.1 C and went up to 91.5 C.

Glasses 9 to 12 took 11 minutes to collect. Still holding strong at 5 litres per hour collection rate. Temp_in went up from 92.4 to 92.7 C. Temp_up started at 91.6 and went up to 92.1.

Glasses 13 to 16 took 13 minutes to collect. Collection rate of about 4.5 litres per hour. Temp_in from 93.0 C to 93.5 C. Temp_up went from 92.3 to 92.8. Glass 16 was done at 12h07. Less than two hours after I started up the iStill!

Glasses 17 to 20 were collected in another 13 minutes. That’s 4.5 litres per hour again.

Glasses 20 to 24? That took another 13 minutes. I collected glass 24 with temp_in at 94.8 and temp_top at 94.1.

Glasses 25 to 28 went in another 13 minutes. Collection rate could have been a bit lower. I ran out of 0.25 litre glasses and switched to  glasses  holding around 0.2 litre.

Glasses 29 to 32 took 14 minutes to collect. Collecton speed is slowing down a bit, but still very impressive at around 3 litres per hour. Glass number 32 I collected with temp_in at 96.5 degrees C. Temp_up was 95.7.

Last 0.8 litres (until temp_in was 97.5 C), I collected directly in the feints receiver.

I forgot to look at the clock, but I think I finished a bit after 13h00.  The glasses, 32 in total, are airing out as we speak.

Some conclusions

As a pot distiller, the iStill 50 is very, very fast. Total run time, from start to finish, was around 3 hours. Total time I collected product was just 1 hour and 50 minutes. In that time I collected around 8.7 liters. That’s over 4.5 liters per hour. On a low ABV wash (not low wines!) I find that very impressive.

Heads are stacked and drawn of at azeotropic temperatures and ABV, allowing for a very small portion of the drink being cut for heads.

How much? And how is big is the final cut? And will it taste good, or will tailes come over sooner rather than later?

I will let you know when I did final blending of the glasses!



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