Tuesday Tech Talk!


Tuesday is about tech talk. So what shall we discuss? Well, let’s dive into direct electric heating, today!

Advantages to electric heating

Electric heating has three major advantages:

  1. It is a direct form of heating that creates more taste formation while distilling;
  2. It is very efficient;
  3. It is ultimately controllable.

Disadvantages to direct electric heating

If you read the literature on direct electric heating, one potential downside shows up: direct heating takes place over a smaller contact area than indirect heating and hence the risk of scorching is potentially bigger. Underneath I will explain the reasons and solutions.

Diving in deeper

When we look at the potential issue of scorching, it is good to take the above paragraphs into careful consideration: the potential for creating more taste more efficiently shouldn’t be countered by potentially creating scorching issues. Yet, both the taste cascade known as the Maillard Reaction and scorching take place in situations where more energy in applied over a smaller surface area.

What is good, and what isn’t? Let’s start with a definition of energy input for that smaller heating area. Energy we measure in Watts, surface area in square centimeters (cm2). So any definitions of what’s good and what’s potentially bad should be measured in terms of Watt/cm2.

Now, let’s look at heating up water. Water does not scorch during distillation and neither does alcohol. But we often don’t distill just water and alcohol. Instead, we usually distill a combination of water, alcohol, and some organic matter. The organic matter can be pulp or grains.

For a heating element, we can distinguish two situations. One is that it is primarily surrounded by liquids, the other is that it is primarily surrounded by non-fluid organic matter:

  1. Heater/Liquid Contact;
  2. Heater/Particle Contact.

Due to their more fluid character, heater/liquid contact does not present a scorching issue. Due to its more fixed character, heater/particle contact presents a greater potential risk for scorching. The trick therefore is to either run a liquid, or to “liquify” a pulp / grain wash.

Liquids, even the thickest liquids, like fermented molasses for rum making, can be done easily with direct heating. As long as the energy input is no more than 15 Watt per cm2. So if we stay below 15 Watt/cm2, heater/liquid contact, even with the dirtiest blackstrap molasses, can be distilled easily, with full benefits in terms of taste and efficiency, and without the risk of scorching.

For heater/particle contact, for instance when we have fermenters sitting directly in a non-moving grain bed, a lower power setting is needed. The magic number is 8.5 Watt/cm2. So, if we want to distill on the grain or pulp we can do two things:

  1. Make sure the heaters dispers less than 8.5 Watt/cm2;
  2. Agitate the wash, because agitation makes the total water/alcohol/particle mix fluid again.

iStill NextGen and direct electric heating

The heaters we use in the iStills NextGen deliver a maximum of 10.5 Watt/cm2 during the distillation heat-up phase or during mashing, and only 6 Watt/cm2 during the actual distillation process. If heating is needed to start-up the fermentation cycle, even less Watt/cm2 energy input is applied.

This means that any iStill NextGen can deal with dirty washes, with yeast, and blackstrap  with ease. But if you want to distill with all the grain or pulp in the boiler, the heat-up phase may be just a bit too much.

The solution? Order your iStill NextGen with agitator! The new Jet Propulsion Agitator will make sure there is perfect particle distribution, meaning that every liter of boiler content has the same (and thus minimum) amount of particles present.

It also means that by agitation the grain bed or pulp bed is no longer touching the heaters for prolonged periods of time. Our boiler design and agitation system liquify the grain bed.

The combination of low wattage / ultra low wattage heating with our revolutionary agitation system in our square flush boiler allows for more taste formation in an efficient way, while completely taking care of  any potential scorching effectively. And that’s something else that makes the iStill NextGen line-up unique: it not only allows you to mash, ferment, and distill in one unit, it also allows you to reap the benefits of direct electric heating without any negatives.





4 thoughts on “Tuesday Tech Talk!

  1. You said the nature gas is the further.
    You said direct heating is better.
    You said direct heating create more maillard reactions.
    And now you turning to the electric heating?

  2. Well, Wavy, it is almost a poem you have written. Not sure what you are trying to say, but yes direct heat is better. More economical and more/better taste. There are two options of direct heating: gas and electric. Electric gives more control, gas is at some places cheaper. Hmmm … its not like we are turning to electric, really. We have been producing electric units from the start onwards.

    • Dear Odin, you are my enlightenment teacher in whiskey producing, I’ve read out all of your articles, and no doubt I will follow all your viewpoint. Beacuse no one ever explain the principle so detailed like you, professional and easy to understand. So plz let me say thank you to you! Just maybe the direct fire heating has deeply marked in my mind, so I almost forgot electric also have a very high temperature on the surface and it can also create millard reaction.

      Sorry boss, thanks for replying.
      BTW, my plan is to have a istill in my studio. I belive that science is power.

      Best Regards

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