Neutralizing Dephlag Induced Taste Variance!


If you, as a craft distiller, want to make the best spirits possible, you need to have full control over all variables. If you want to make the beste spirits consistently, you need even more control. This iStill Blog post dives into the influence of dephlagmator induced taste variance, how it can screw up your run, and how iStill’s innovations help solve the issue.

The influence of a dephlagmator on distilling

A dephlagmator is a pre-condensor that sits high up in the column. When a beer or wine is brought to a boil, gasses rise up through the column. In a potstill, the gasses go up  via the riser and then migrate horizontally via the line arm and then are bend downwards before entering the secondary or product cooler.

Dephlagmator: a partial heat exchanger …


In a (traditionally plated) column a dephlagmator or dephlag is added near the top of the column or riser. The aim is for the dephlag to cool a certain percentage of the gasses back to liquid state. This liquid, called reflux, falls back down in the column and can be reprocessed by that column for further purification and concentration. For instance via bubble cap plates or perforated plates in that column, under the pre-condensing dephlag.

As a result of part of the gasses being cooled back to liquid phase – and them being redistilled lower in the column – rising gasses and reflux exchange molecules, making the reflux lower in ABV, while the gasses get a boost in alcohol percentage. When those now enriched gasses hit the dephlag again, another portion of them is turned into reflux, while another faction leaves – as gasses – the top of the column to be cooled down into spirits.

The dephlag is in use since the 1860’s and is still in use on most column stills for its capability of creating reflux. Here is a schematic drawing (yes, by yours only) of how a dephlag works:

Dephlagmator: reflux vs. enriched gasses …


How dephlag induced variance screws up your run

The dephlag is fed by gasses from the bottom and by cold cooling water from the side. The cold cooling water condenses (part) of the gasses. Near the top redistilled gasses leave the system, to meet-up with the secondary product cooler. Also near the top, now warmer cooling water exits the dephlag.

Even though dephlagmators do a good job at creating reflux, they come with a set of severe drawbacks. Drawbacks have to do with that dephlags run depending on cooling water. More water in means more cooling, more reflux, more purification, and less product. Less cooling water throughput means less reflux, less purification, and more product comes over per hour. But cooling water isn’t a given. It, and a number of other variables, has certain properties that are vulnerable to variance. Here are the biggest confounders:

  1. How cold or warm is the cooling water to start with?
  2. At what water pressure does the coolant come over?
  3. What’s the delta between the cooling water, the still, and the gasses?

A dephlag “controlled” column has a lot of variables to deal with. And each variable shows variance. Cooling water may be colder in the winter or in the morning, resulting in seasonal or temporal changes in cuts, flavors and ABV.

Water pressure may be lower early in the morning and later in the evening. Less water pressure means the dephlag doesn’t cool so much during (at least) parts of the run, resulting in lower ABV hearts cut and more smearing of heads and tails.

How hot is your distilling hall? And how does that change over time? For sure the delta between the coolant, the still’s outside and the gasses is important. And when it is constantly changing, so are your cuts, so are the flavors you bring over in your spirits!

When using a dephlagmator, the craft distiller will struggle to make a spirit the best way possible. And recreating the same drink over and over again becomes neigh impossible. In short?

Due to dephlag induced variance, you just screwed up your run …

mad man

The iStill solution to dephlag induced variance

Our mission statement is “Distilling made easy”. And in order to help make distilling easier, it has been our goal to minimize dephlag induced cooling water variance. We succeeded. This paragraph explains how we did it.

iStills do not have a dephlag. Instead of a pre-condensor high up in the column, we placed a full-size condensor above the column. “Full-size” means ALL the gasses are cooled down to liquid phase. “Above the column” means just this: there is no U-tube with consecutive after cooler on top of the iStill condensor. All the gasses are cooled down to liquid and fall down to the collection plate system. It is at the collection plate system, with the help of the robot, that selections between “product out” (spirits) and “product back into the column” (reflux) are taken.

Since all gasses are cooled back to liquids, the iStill design has no variance at all. Cooling water temperature does not influence cuts or purity or ABV. Nor does water pressure (or changes in water pressure). Finally, delta’s between column, distilling hall, and coolant don’t play a role anymore either.

As long as there is enough coolant, the iStill creates a distilling environment free of dephlag induced cooling water issues related to temperature, pressure, and delta’s! The innovative iStill column and condensor set-up allows you to make your drinks the best way possible. With the same cuts, ABV, and flavors … each and every run.

This is how iStill’s full-size column condensor works …




Irish Whiskey now GI!

The European Commission has confirmed geographical indication (GI) status for Irish whiskey as well as Irish cream liqueur and Irish poitin.

For more reading, please see:

iStill 5000 Copper: the ultimate Irish whiskey still …


Neutralizing Air Pressure Variation!


If you, as a craft distiller, want to make the best spirits possible, you need to have full control over all variables. If you want to make the beste spirits consistently, you need even more control. This iStill Blog post dives into the influence of air pressure, how it can screw up your run, and how iStill’s innovations help solve the issue.

The influence of air pressure on distilling

When distilling spirits, we aim to first concentrate the alcohol by a fast stripping run. Thereafter, a slower finishing run is performed where the heads, hearts and tails fractions are separated by means of boiling point differences between those fractions. Heads come over at lower temperatures than hearts and hearts boil off at lower temperatures than tails.

From the above alinea it becomes clear that boiling points are key to good cuts management. Just as good cuts management is essential to bring over the right flavors and create that above top shelf spirit you are after.

So good cuts management, essential to the creation of great spirits, depends on boiling points. And guess what? Boiling points depend on air pressure! And since air pressure is not a given, not a set parameter, it creates variability in your cuts, translating into potentially sub-standard quality drinks.

Air pressure structurally differs between locations. As a general rule: the higher altitude your location is, the less air sits above your still, the lower the air pressure is. Air pressure is also variable in time. When a new weather front moves in, air pressure will rise or lower. The issue with this? As a distiller you are constantly confronted with different air pressures, translating to different boiling points. Between runs and during runs.

Ethanol, for example, boils at 78.3C or 173F. At standardized sea level air pressure that is. Higher air pressure pushes boiling points upwards by up to 0.5 degrees easily. Lower air pressure lowers ethanol’s (and other components) boiling point.

Air pressure sensor old style …


How air pressure can screw up your distillation run

Say that you follow a set of standard cut points for heads, hearts and tails of your whiskey run. Here is what they may look like:

  1. Heads are collected until 80C;
  2. Hearts are collected until 95C;
  3. Tails are collected until 98C.

You came to the above cut points, because that’s how you liked your first whiskey run. Why not repeat that, right? Well … because the air pressure variance will hamper your ability to arrive at the same results.

Imagine the following real life example. You did your first whiskey finishing run at sea level and – by coincidence – at standard air pressure. But now that you just started finishing your second bats, the weather changes and – with it – the air pressure. The boiling points are off by (say) 0.3C. That is 0.3 C lower.

You make your cuts according to plan at 80, 95 and 98 degrees Celsius, but you should have cut at 79.7C, 94.7C, and 97.7C. You have just collected more heads than before, limiting the fruity flavors in your whiskey. And you hearts to tails cut was also 0.3 degrees late, resulting in more root-like and nutty flavors in your whiskey than usual.

Don’t make the mistake of thinking that 0.3 degrees is nothing. In terms of a big production still, you may well be smearing too much early tails into your hearts for like 20 minutes! In short?

Due to air pressure variance, you just screwed up your finishing run …


iStill’s innovation to help solve air pressure variance related problems

“How do we solve air pressure variance induced, sub-standard cutting?” became an iStill mission. The first generation iStills calculated the boiling point (and any variance from “standard”) by stabilizing the units, after heads were taken, for long enough to achieve the pure azeotropic ethanol boiling points near the take-off point of the column. We would then use that input to correct cuts.

The latest iStills are far more sophisticated. They are equipped with a sensor that monitors air pressure every second. Following the sensor’s input, the programming calculates any deviation from “standard” on a second-to-second basis. Thus giving your iStill perfect insight into boiling points that then automatically translate into perfect (corrected) cut points.

We call this feature “Dynamic Cuts Management” or DCM, and it is one of the reasons why iStills make better product more consistently than any other still out there. It now comes standard on all our units. It can be retrofitted on most of the existing NextGen units.

Air pressure sensor iStill style …


iStill Spirits Design!


Over the years, we have helped our customers design a total of close to 250 different drinks. Gins, vodkas, whiskies, brandies, rum, and specialties like for instance Mahula Liquor from India. In this iStill Blog Post, we’ll dive deeper into how we help craft distillers, in designing the best possible drinks for/with them. And what the investment is at your end.

Our extract and essence library …


Designing a drink for you usually involves two steps. First we design a recipe. And we then translate that recipe to a process. Let me give an example:

Say you want our help at making an Irish whiskey. We’ll discuss the grain bill, and its influence on New Make taste. We’ll talk about mashing procedures and how fermentation protocols help create certain flavors. The next step would be that we discuss (and help you decide) on what flavors to bring over and emphasize during distillation. Aging (what barrels, what woods?) would be next on our to-do-list. We’d run test batches on the iStill Mini to fine-tune and to bring your whiskey to perfection.

Or, on another note, say you want our help in creating a top-shelf gin. We go over flavors and herbs, and draw-up a list of ingredients, that we then run on the iStill Mini until we hit it home.

Consider the above paragraphs to be your “recipe”. But we go one step further. We help translate the recipe into a run procedure by translating it into an iStill program for the masher, fermenters, and stills. That way, when you go back home, you just order the ingredients, while we upload your latest recipe, and start the machine and kick-of production.

iStill laboratory equipment inventory …



Here, at iStill, over the years, we have designed close to 250 drinks. Whiskies, gins, vodkas, rums, brandies, and specialties. Most of them for our customers. And most of our customers have won amazing prices with the spirits we helped conceive.

iStill Spirits Design has a very straight forward pricing model. If you want us to create a recipe and production process program, we charge you EUR 5.000,-.

If you want to order iStill Spirits Design, if you want to hire our facilities and expertise, if you want to learn more about how and where we can help you out, please contact Sebastiaan Smits, Manager iStill Spirits Design via

Sebastiaan Smits …





Update iStill Mini Availability!

We are delighted to see that our new, small product development still, the iStill Mini, is a huge success. We just shipped four more to customers all over the world. After delivering four others personally, just a week ago, when we did the Denver based iStill University Workshop.

Why share this information? Well, guess what? The last batch of iStills Mini is nearing depletion. There are now only five more left. Of course, we will start building another batch of 50 new iStills Mini, but that will only be ready in 10 weeks from now.

So, if you want to order an iStill Mini, and you need one quickly, please reach out to today …

Four more iStills Mini fly out to customers all over the world today …


Scottish Whisky iStill!


Any iStill can make any product. Whisky, vodka, rum, brandy, or gin … you name it, the iStill can make it. But that’s just the production side of things. Sometimes additional rules or laws apply. Scottish single malt is an example. Additional rules are set in place.

In this iStill Blog post I will explore what those additional rules are and how iStill helps customers – with its advanced technology – at making amazing Scottish single malt whisky. Yes! iStill made Scottish single malt whisky according to the rules of the Scottish Whisky Association.

Scottish single malt whisky

Scottish single malt whisky is a full bodied, three dimensional spirit, produced by batch distillation. But there are more rules applicable. For instance: it has to be made in Scotland, but there is more, so let’s dive in deeper.

Scottish single malt whisky needs to be distilled in a potstill. Otherwise it cannot be called Scottish single malt whisky. Not just any potstill though! The potstill needs a lyne arm and at least all the gases need to touch copper only. In practice, this means that the top of the boiler, the riser and the lyne arm need to be all copper. The boiler and product cooler can me made out of other materials as well.

The iStill solution to Scottish single malt production

We are proud to announce that we can now help out Scots that want to produce single malt whisky. We hereby introduce the iStill 500, 2000, and 5000 Copper. Not because it makes better whisky, but simply because it is the only way in which we can help out our Scottish customers that want to produce single malt whisky.

The units come with a PLC, automated run programs, and automated cuts for heads, hearts, and tails. The units are directly fired and can be fitted with our famous Jet Propulsion Agitator System (J-PAS). The new range comes standard with Dynamic Cuts Management for an unmatched batch consistency and production efficiency.

The 500 liter version produces 50 liter of spirits per hour. The 2000 liter still produces up to 100 liters per hour. The iStill 5000 Copper produces up to a whopping 200 liters per hour.


The iStill 500 Copper costs EUR 75.000,-. The iStill 2000 Copper costs EUR 125.000,-. The biggest (so far) version is the iStill 5000 Copper. It sells for EUR 175.000,-.

On a five year rent-to-own basis, the iStill 500 Copper can be leased for EUR 1.596,- per month. The iStill 2000 Copper would cost EUR 2.660,- per month. The iStill 5000 Copper can be leased for EUR 3.724,- per month.

Request for more information

For more information, please reach out to