Questions & Answers (1)!


We had a successful Drinktec 2022 in Munich. Hundreds of brewers and distillers visited our booth, asked questions, and expressed their interest in our disruptive technology. But what did they ask? What were the questions on their mind, as they saw the iStills? In a series of posts called “Questions & Answers” we will summarize the questions that were asked most as well as our answers.

Question 1

Why are your boilers square instead of round?


Depending on the type of spirit you produce, agitation is needed, so that the boiler contents are well-mixed. In a round boiler the boiler contents will start to move with the agitator system. As the speed differential between the agitator and the boiler contents drops, so does the actual mixing energy that is applied. Therefore, mixing in a round boiler is not very effective and the goal of optimal dispersal of grains or herbs or grapes is not achieved.

As a result, still manufacturers, that do add agitators to round boilers, often have to resort to over-mixing the boiler contents. The now very fast turning agitator throws boiler contents into the gas bed above the liquid bath. This disruption of the gas bed, from which the riser or column harvests its gasses, leads to fluctuations in vapor speeds in that riser or column, hampering flavor consistency and cuts management. Boiler and agitator longevity will be comprised too, as both are over-worked in order to create a higher degree of mixing.

Also, as the boiler contents start to move with the agitator – in a round boiler – a vortex is created. The vortex sucks gasses downwards, competing with the riser or column. This interferes with the riser or column doing its work properly. As with over-agitating the boiler contents, a vortex hampers production speed as well as flavor consistency and cuts management. What essentially happens, in both cases, is that micro burst of over- and under-pressure influence the vapor speeds inside the distillation system, resulting in unwanted smearing of heads and tails flavors into hearts.

The vortex has a secondary negative effect. As the vortex reaches downwards, more boiler contents are pushed upwards, via the sides of the boiler, limiting the fill-grade of that boiler. Especially in combination with over-mixing, this can result in a big difference in gross vs. net boiler capacity. In a round boiler with a gross content of 650 liters, the maximum net filling will be 350 to 400 liters only. The choice for a round boiler severely limits your production capacity, as you have to do more yet smaller runs.

How a square boiler with flush corners helps? Well, first of all the boiler contents cannot start to spin with the agitator. The moment the wash start to move with the agitator, the corners – that are further away – generate a counter rotational movement, keeping the boiler contents in place and thus maximizing the speed differential between agitator and wash. As a result all the energy put in by the agitator translates into actual mixing and perfect particle distribution.

Since no vortex is created – in a flush-square boiler, that is – and no over-mixing needs to take place, the gas bed above the boiler contents is very stable. The riser and column can do their work under optimal conditions, which results in higher production rates, better quality spirits, and recipes that are reproducible from one run to another.

Finally, our 630 liter gross capacity iStill 500 has a net fill rate of 500 liters. That’s about 30% more than an equally sized round boiler. The benefit? You get more still for your buck. You can process bigger batches. Your yield – and therefore your income – is significantly increased.


What reactions did we get, when answering the question of why we have flush-square boilers? The reactions ranged from “that makes total sense” to people being flabbergasted.

At your service!

The iStill Team

Square boilers matter …

Copperpenny Gin Blows Judges Away!

The Spirits Business’s Judges were blown away by Copperpenny Gin 005. Jan and Jenny congrats! We are so happy and proud that you are iStill customers. Spirits Business’s judgement of your 005 gin is amazing. Here it is:

Canadian entry Copperpenny Gin 005 blew the judges away in this year’s blind tasting, securing a top medal in the competition: Master.

Cheong Thong’s tasting notes included: “Good hit of green juniper on the nose with pink peppercorns, and sansho on the finish.”

Athavia also greatly enjoyed the gin. She picked up notes of “lovely cardamom” leading to a “light and fresh palate with a backbone of good juniper”.

Copperpenny Gin 005 is bottled at 43% ABV …

iStill is London Craft Distilling Expo’s Main Sponsor!

We are sponsoring London’s Craft Distilling Expo once more. And as the world’s leading distillery manufacturer we decided to not be just any sponsor, but to be the event’s main sponsor.

It’s the kind of sponsorship that comes with benefits. Like free tickets for our customers (or soon to be customers). When the Craft Distilling Expo is? October 6th and 7th. At the Truman Brewery on Brick Lane.

Are you in the process of purchasing an iStill? Are you an iStill customer? Then reach out to to get one or two free tickets. If enough of our customers show up, we’ll do Beer & Burgers on the evening of the 6th!

Master Distillers Course – Customer Feedback!

Datum: 11 september 2022 om 08:54:57 CEST
Aan: Veronika van Eijk
Onderwerp: Thank you

Good morning Veronica and Odin

I would just like to thank you, and all those at IStill, for an amazing week and a brilliant course. You are supported by a fantastic team, and I would particularly like to hail Sebastian, Willem and William as the “triumphant triad” driving the course.

Sasha and I look forward to seeing you in London in a few weeks time and once again quite simply, thank you.

Best wishes

Brian Cohen

Do you want to participate at the industry’s best educational program? We have a new course planned from November 14th till November 17th. In Amsterdam, at iStill HQ. If you want to register, please reach out to!

Comparing Energy Efficiency: Traditional vs. iStill!


Today, we are diving deeper into the topic of efficiency. As many parts of the world see a rise in energy costs, it is a topic that needs to be addressed. Yes, we all know that iStills are the benchmark, when it comes to efficiency, as they are compact, controlled, and insulated. Traditional stills have outdated designs, that hark back centuries, and are not insulated. But how much is the difference really? Can we quantify it? Put numbers on it? Yes we can and yes we will. Here ya go:

Setting the stage

In one corner, we have the traditional distillery set-up: a 550 gallon masher and stripping still and a 140 gallon finishing still. Both are jacketed and steam-powered. The steam-engine runs on propane.

In the other corner sits the iStill 2000. It is electrically powered and can finish a 2,000 liter batch in one go. No need for double distillation, no need for two stills, no need for a steam-engine.

What will they fight over? New make whiskey. Or whisky. Or Bourbon. The goal is to mash, strip, and finish a total of 4,000 liters or 1,100 gallons of wash into 62.5% new make spirit, that’s ready to hit the barrel. Who will be more efficient and by how much? The traditional set-up or the iStill? And, as a bonus, we’ll also translate energy usage into energy costs.

Traditional efficiency

Based on a real world example by now iStill customer Aris Aristides, that ran a traditional set-up, making American whiskey in the USA, here are his numbers:

  • Mashing 2,000 liters in the 550 gallon masher costs 30 gallons of propane;
  • Two mashes therefore equal an energy use of 60 gallons;
  • Stripping 2,000 liters in the 550 gallon stripping still costs 30 gallons of propane;
  • Two stripping runs therefore equal an energy usage of 60 gallons;
  • The finishing run consumes another 30 gallons of propane;
  • Total propane used is 150 gallons;
  • 150 gallons of propane equals 600 liters of propane (yes, going metric here);
  • One liter of propane provides 7 kWh of energy;
  • So mashing, stripping, and finishing 4,000 liters into new make spirit costs 4,200 kWh.

Aris’ costs when running a traditional, copper set-up …

iStill efficiency

Based on two real world examples, from a French and a Dutch customer, that use the iStill 2000 to make new make spirit in one go, we come to the following energy efficiency numbers:

  • Mashing 2,000 liters in the iStill 2000 costs 150 kWh of electricity;
  • Two mashes, for 4,000 liter total, therefore equal an energy use of 300 kWh of electricity;
  • Distillation run time is 10 hours (including heat-up, based on the latest 54 kWh model);
  • Power usage of 46,5 kW per hour throughout the distillation run;
  • Total power usage, in order to distill a 2,000 liter wash into new make, is 465 kWh;
  • Total power to distill 4,000 liter of wash into new make spirit is 930 kWh;
  • So mashing and distilling 4,000 liters of wash into new make spirit costs 1,230 kWh in total.

The iStill 2000: the craft distiller’s favorite whiskey production machine …


Based on (currently less disrupted) American energy prices, the following can be noted:

  • One gallon of propane costs $ 3.-, so a traditional runs, that use 150 gallons, cost $ 450,-;
  • One kWh costs $ 0.14, so the iStill runs, that use 1,230 kWh, cost $ 172.-

The outcome of the battle?

The iStill 2000 uses 1,230 kWh to mash and distill 4,000 liter. The traditional, indirectly fired, steam-heated, copper set-up used by Aris in his previous, pre-iStill distillery uses the equivalent of 4,200 kWh.

Using an iStill instead of a traditional set-up saves the craft distiller a whopping 2,970 kWh. The iStill is 3.5 times more efficient than the traditional distillery!

Mashing and distilling 4,000 liters results in 440 liters or 2 barrels/barriques of new make spirit at 62.5%. On a traditional, copper set-up it costs $ 450.- to produce this amount. With the iStill the energy bill is just $ 172.-.


If you want to be an energy efficient craft distiller, buy an iStill. If you want to be a cost efficient craft distiller, buy an iStill. If you want to be an environmentally friendly distiller, buy an iStill. And since our customers win more awards than anyone else out there: just buy an iStill.