The purpose of the distillation process, in the production of alcohol, is to purify the liquid in the distillation column.
This is achieved by heating and vaporizing the liquid. When the vapor recondenses into liquid, it is collected.
This liquid is considered to be more pure than the original liquid as many of the impurities that were present in the liquid prior to distillation have been removed when the liquid evaporated.
The liquid is not only more pure, but the alcohol concentration is much higher.
Therefore, the distillation process is a key process in the production of alcohol and the source of heat used to distill the liquid is equally important.
As the heating source is the power behind the distillation process, it is of primary importance in this step of the process. Consideration needs to be given with regards to what type of heating source will be used.
Many factors will come into play, such as the cost of running such a heating system, the cost of purchase, as well as several other key factors which I will be addressing in this article.
How much power do I need
There are many factors that will come into play when deciding how much power is needed for a distillation column heating source. The first thing to consider is the design and size of the column. It goes without saying that larger columns may need more power to bring the entire contents of the column up to boiling point so that vapor can form.
Is the heating source for a home distillery or is it for an industrial distillery? Again, this comes down to the size of the operation.
You need to consider how valuable time is for you. If this is a hobby and you are doing it for fun, then the time it takes to heat up the liquid doesn’t really matter. However, if you are running a business, then the amount of time distillation takes cuts into your profit margins. You may need a heating source that can provide a sufficient amount of power in a short amount of time.
This keeps operations running at full speed.
There are several other factors that also come into play, such as packing, heat loss, condenser efficiency etc. that need to be considered.
You may need a calculator to help determine the amount of power you will need. For example: To heat 50 gallons of liquid by 200°F in 30 mins (0.5 hrs); 3.1 x 50 x 200 / 0.5 = 62,000 Watts.
This is simply an example to demonstrate the intricacies that are involved in heating a distillation column in the best possible time frame.
Scorching the grains or botanicals
For a brewer, there are few things quite as disappointing as testing the last brew only to discover the taste of burnt or smokey notes.
Grains and botanicals are most likely to scorch or burn if they pass by or settle on a heating element. Especially if there is no water present to discharge the heat.
The density of the heating element should be calculated as high density heating elements should best be avoided. In order to calculate the density of the heating element, simply divide the total wattage of an element by the surface area.
Ideally, the watt density should sit below 110W/in².
One of the most important things to consider during distillation is the amount of control that the brewer holds over the process and the heat.
Keep in mind that during the initial phase of distillation more heat and power may be required and this will need to be adjusted during the course of the operation.
You want to prevent the liquid burning and you also want to make sure that the power density matches the liquid.
Time to heat up
When it comes to home distilleries the time it takes to heat up the contents of the tank may not be that important. Especially if this is only a hobby.
The larger the operation the more time to heat up matters. Every second that it takes the contents of the still to heat up is money being drained from the profits. You want to create pure, high concentration alcohol but you don’t want to take copious amounts of time to achieve this.
Some heating methods are known to produce heat much faster than others but cost will also come into play with this consideration. You may need to pay more for a heating device that can harness the appropriate amount of power to quickly and sufficiently heat up the liquid.
Cost to run
How much money do you plan to invest in this project? Some professional heating systems can really climb into your pockets. Other methods are extremely cost-effective and produce rapid results.
In some states, the cost of electricity is much cheaper than in other states. In addition, heating the still using fired wood may be more inexpensive for some, but the cost will be leveled out with the type of still as using fire requires a specific design, in the still.
Cost to buy
Again, how much are you considering investing in this project? Some heating sources are built into the tank and may run up a hefty bill.
Other heating sources are practically free, such as in the case of wood fired heating, and the only cost incurred is the price of wood.
However, this may also be evened out by other costs such as obtaining a license to start an open fire.
There are heating sources such as the immersion heating source that is very clean and requires very little to no clean up at all.
Other methods such as using wood to create fire under the distill may be messy, create a smell, and require a lot of cleaning up.
A look at the different heating methods
Let’s have a look at the best heat source for a distillation column.
Electric (Direct immersion)
Immersion heaters, also known as bayonet heaters, have a heating element that is inserted directly into the liquid in tanks in order to heat up the entire contents of the tank. It’s an economical, fast, and efficient method of heating liquids.
Immersion heaters can be immersed in the liquid or mounted on the side. The heating coils of immersion heaters bring the contents of the tank to the desired temperature quite rapidly. The heater consists of tubing and creates direct heat transfer.
The different parts of an immersion heater are:
- Heating element
- Power density
- Temperature range
- Sheath material
A sheath holds the electrical resistant heating element that is submerged in the liquid. Between the sheath and the element is an enclosing jacket. Once the heating element is activated, electricity is transferred via the heating element to the liquid. Firstly, the element heats the enclosing jacket which in turn heats the sheath that finally heats the liquid.
Two elements determine how fast the contents of the tank are heated:
- The quantity of heat transferred
- The power level of the heat
It’s important to note that the sheath material is important as different sheath materials react differently to the different liquids.
Another key factor is the power density, which must fit the liquid. This requires some calculation. If the power density has not been calculated to meet the liquid, it can scorch the liquid. In turn, this creates a heat buildup in the heating element.
The wattage determines if the heater is able to deliver enough power to heat up the contents. Different wattage may be required to initially heat up the liquid versus heating during operations. In addition, heat loss needs to be taken into account as this will affect how much heat is required to bring the contents to the desired temperature.
Aliminium is the preferred enclosure material due to its thermal resistance. The temperature range of the heating source will depend on what it is being used for. Industrial direct immersion heaters have much higher temperature ranges in order to accommodate the amount of liquid that needs to be heated at any given time.
A hot plate is a small appliance that sits on a tabletop. It is self-contained and features one or several electric heating elements. It produces heat through the use of electricity.
The electricity is run through the heat coils of the hot plate and these coils contain a high level of electrical resistance. The distillation column is placed on top of the electric hot plate which heats the contents of the column from the bottom upwards.
Depending on the make and model of the hotplate, you can expect it to draw, on average, about 1,200 watts of power.
The heat up time will depend on the wattage of the hotplate. The lower the wattage, the longer it will take the column to heat up. This, of course, also depends on the size of the column and the amount of liquid that needs to be heated up.
A key consideration when using an electrical hotplate is that the bottom of the boiler should make sufficient contact with the coils on the hotplate. This ensures consistent and reliable heat transference from the hotplate to the boiler.
Another key factor to consider is the use of electricity. The size of the boiler, the amount of liquid to distill, the time frame within which you hope to finish the project will all affect the amount of electricity used and could run up the bill substantially.
Adding a controller to the hotplate means that the temperature can be regulated and the on/off cycles of broiling can be controlled or eliminated.
Here are some examples of hotplates and the liquid amounts that can be heated using the specific wattage:
- 110 Volt/1500 watt is sufficient for up to 8 gallons of liquid
- 220 Volt/2000 watt is sufficient for up to 18 gallons of liquid
This should give an indication of how much wattage the hotplate needs to produce in order to heat up specific size boilers and liquids.
The heating element sits inside a jacketed kettle.
A jacketed kettle consists of a boiler body that can usually tilt 90 degrees, a worm rod and wheel, and a stirring device. It is predominantly used in industrial and commercial settings to heat liquid for distillation. It comes in various sizes. The deep kettle is mounted on legs or a pedestal which stands on the floor.
A metal jacket covers the bottom two/thirds of the kettle.
The kettle body is usually made of high-quality stainless steel. It is an excellent device for thermal efficiency and has the ability to uniformly heat the contents inside the kettle. Heat up is controlled and can be slow or rapid.
This device does consume large quantities of power and is therefore more suited for industrial use as it does require three-phase electricity to power the kettle.
Essentially, it is a self-contained steam boiler that produces low pressure steam. You can expect minimal heat loss with this piece of equipment.
The devcie comes with a control panel.
Direct fired (Wood)
Stills are heated over direct fire. This method is very rare and is not used as frequently as it once was.
This method is known for creating deeper and more complex flavors during distillation. This type of heating method does produce significantly higher temperatures within the still.
It is known for creating a Mailard reaction within the still that infuses deep flavors into the liquid. For example, it could create, on one extreme, a burnt chocolate aroma, and on the lower extreme, nutty/ caramel aromas.
This method also means that the brewer will have less control over the temperature of the still during distillation and may also cause hot spots or areas around the broiler that experience more heat than other areas. Though it needs to be mentioned that with a little planning ahead of time, the temperature can be controlled.
In addition, direct fired heating sources require a specific type of still design. The base of the still should feature a convex design so as to ensure even distribution of heat. In addition, the extreme heat requires a heavier copper gauge.
These stills are equipped with a rummage that helps to clean up the copper and prevent burnt aromas.
The up side about this heating method is that no money is spent on an electric bill for a home distiller, but control of the heating source is a major factor. This means that additional time and effort needs to be exercised in order to plan around this element and make sure that the liquid does not burn.
In addition, due to laws regulating open fires, a permit may first be required for home brewers.
Direct fired (gas)
Firstly, it needs to be mentioned that using direct fired gas to heat up a still is very dangerous when done indoors. This method is best suited for the outdoors where there is fresh air that can circulate around the still.
It is also much more inexpensive than using electricity. Much like the wood fired stills, the gas fired stills incorporate gas to burn the flame that heats up the still.
There is much more control with this method as the intensity and size of the flame can easily be controlled to accommodate for the different stages of the distillation process.
However, this method has numerous and extremely dangerous safety issues. It’s difficult to find a gas powered still on the domestic market for this exact reason. Especially since the liquid being distilled is highly flammable. It could easily cause an explosion and an ensuing fire.
Steam is generated in a pot still. This steam is then moved through the material in order to vaporise temperature-sensitive compounds.
Steam is very efficient at heating up the mash in the still. As the steam bubbles enter the mash, the bubbles start to condense and collapse. There is no concern about scorching the mash using this method.
There are a few drawbacks to using this method. The ABV is lowered slightly and using steam to heat up the mash will dilute the mash.
This is a relatively safe and cost-effective heating source that can effectively and efficiently heat up the contents of a still, rather quickly. The temperature of the still can easily be controlled and the results produced using this method seem to be highly favorable.
In this heating method, one tank sits inside another tank with a jacket. The second tank with the jacket is filled with oil. This transfers heat from the heated oil to the exterior wall of the tank that sits on the inside. The heated exterior walls of the second tank then heats the liquid contents inside it.
This system is pressure-less for safety reasons.
There is optimal control of the heating temperature. This method is extremely effective as a heating source and allows for even heating of the contents.
It is, ideally, more suited to industrial settings due to the cost involved in maintaining such a system.
Our recommendation: for a home distiller on a budget
For brewers on a budget, the best distiller would be either direct immersion heating or a hotplate heating system. Both of these use electricity. Keep in mind that the cost of power is much lower in certain states than in others and this should be taken into consideration as well. These are both the most economical and safest options.
Our recommendation: for home distillers wanting more control
Direct immersion distills offer the most control over the heating of the liquid. Therefore, this would be ideal for the home brewer who wants more control over the process.
Our recommendation: For small commercial distillers
For small commercial distillers, steam heated distills or direct immersion may be the best option. Both of these options take the cost of running the operation into consideration, which is a big factor for a small distillery.
Our recommendation: For large commercial distilleries
Without a doubt, if the distillation plant is financially fit, and in order to heat up the liquid rapidly in order to cut down on time, the best options would be oil jacket or electric jacket. Both provide the required power and heat to bring large amounts of liquid up to the desired temperature.