The Best Way to Heat Your Still

There are a couple different ways to heat your still. I’ll comment on each method. I will say however, very frequently if on a shoestring budget the best way is usually whatever resource is available. So, there is that.

Let’s start with the oldest known method. The open flame. There are several fuel sources available. Wood being the oldest known fuel can often be the most readily available. Heating with an open flame does present several safety challenges since the rendered finished product during distillation of spirits is highly flammable. One could argue that an outdoor, well-ventilated environment is best for firing the still with wood as the fuel source. Not all jurisdictions will allow for an open flame use. You’ll need to check with your Authority Having Jurisdiction.

Propane or natural gas comes to mind as the next most logical fuel sources for running an open flame to heat the kettle while distilling. In modern times either of these fuel sources are readily available. The only other addition needed would be a burner set up under the kettle for either type of fuel.

Wood or a fuel source like propane or natural gas can also be used to fire a steam boiler, another heating method used for heating a still. Steam is also commonly piped to multiple tanks in the distillery and brewery environment. We’ll touch more on steam use in a bit.

Heat loss into the atmosphere from using an open flame can be significant. Therefore, in order to optimize heat transfer while minimizing loss, some kind of shroud or firebox should be employed to capture or conserve as much heat as possible. Similarly, any insulation on the distilling apparatus will be helpful if exploiting heat / fuel consumption efficiencies is a priority.

Immersion elements are extremely efficient at installing heat directly into the kettle charge since the elements them selves make direct contact with the liquid. The downside to immersion elements making direct contact with the liquid is that if there are any suspended solids at all in the kettle charge, there is likely potential for what we would call scorching. Basically, solids can accumulate on the elements and cook until burned. Think Burnt popcorn.

Needless to say, it is really, really difficult to distill a grain in whiskey with immersion elements for the reason above. However, there are two additional ways to employ an immersion element. We’ll circle back to those examples when we talk about the use of jacketed kettles here in just a bit.

The next most efficient way to distill from a heating standpoint is with steam. More specifically, direct steam injection is a very efficient way to transfer heat. Direct steam injection however is not as efficient as an immersion element and here is why. The heat generated from an immersion element originates on the surface of the element which is making direct contact with the liquid. Therefore 100% of the heat originates and distributed directly into the liquid.

When heating with a traditional steam boiler, even though the steam will release 100% of its energy into the liquid, the origin of the steam source is typically generated away from the kettle and has to be transferred to the kettle via some form of piping. This transfer process represents heat loss.  Furthermore, when distilling with direct steam injection, we will also be introducing more water to the beer by virtue of the steam condensing into the kettle charge. In other words, direct steam injection will dilute the ABV of your beer and therefore represents a loss of efficiency on another level. So, in this case any efficiency gained by the  superior heat up method ends up loosing value because the reduced / diluted abv will require more effort to produce the final product.

Ok, now let move back to the jacketed kettles and heating those kettles with steam or electric. Let’s start with the steam fired jacketed kettle. Again, here we have steam which provides superior heat transfer characteristics. The steam as mentioned above is piped from the classic steam boiler to the still with steam piping and then distributed into a jacket or casing that envelope the inner wall of the kettle. The jacket would be capable of maintaining 15 psi. on a low-pressure kettle. Once the steam is piped into the jacket and makes contact with the inner wall, the heat carried by the steam will transfer through the inner wall into the liquid in the kettle. Once pressure is achieved, the jacket would then be capable of achieving upwards of 245° F.

For the electric (elements) jacketed kettle, The StillDragon design has a small reservoir on the base of the jacket that is fully integrated into the jacket. The reservoir fill level holds anywhere from 10 or 12 gallons to 20 or 25 gallons of water depending on the size of the kettle. The elements are installed directly into the reservoir and heats the water to boiling. The elements do not at all make contact with the kettle (beer or wine) charge. Once the water in the reservoir reaches its boiling point and starts to produce steam, the steam will rise up and occupy the remaining heads space within the jacket. And again, at 15 psi the jacket would then be capable of achieving upwards of 245° F.

So Basically, this electric kettle design is really nothing more than a kettle with a steam jacket that has it’s own self-contained steam generator.

And finally we come the jacketed electric kettle that uses oil as the heating media. The difference here is that oil is used to fill the larger part of the jacket while allowing room for some expansion. Heat up times are typically slower since the larger oil mass in the jacket has to be fully heated and then the heat has then also transfer into the kettle charge. However, once brough to temp the oil is extremely efficient at maintaining its heat and only requires a fraction of the heat otherwise needed to bring the entire mass to running temps.

All heating methods have their advantages and disadvantages and as mentioned at the beginning of this blog post, very frequently if on a shoestring budget the best way is usually whatever resource is readily available, particularly if you are not willing to invest in the infrastructure of a short term lease, rental property for example. 

What is the best way to heat your still? Well, that depends.