Double distilling – sometimes called redistilling – is one of the most common topics we’re asked about.
Is it possible? Does it actually make a difference?
The short answer is that double distilling is completely possible with the Pure Distilling Reflux Condenser, it’s easy to do, and can improve the smoothness of your final spirit.
Let’s take a closer look at what it really involves.
Double distilling simply means taking an already distilled spirit and running it back through the reflux condenser for a second time.
You are not fermenting again and you are not making a new wash. You are refining what you have already produced.
Each time ethanol is passed back through the reflux condenser, additional fuel oils and volatile compounds are removed. The result is a progressively cleaner and smoother neutral spirit.
In fact, during internal testing we have redistilled spirit multiple times and observed just how noticeably smooth the product becomes with each additional run.
If you are using the Pure Distilling Reflux Condenser, you are already producing an extremely clean neutral spirit at around 93% ABV in a single run.
After dilution and carbon filtration, that spirit is perfectly suitable for flavouring and consumption.
So strictly speaking, double distilling is not required.
However, every additional run through the reflux condenser further refines the ethanol by stripping away minor trace impurities. While the improvement becomes more subtle with each run, the overall smoothness profile does increase.
For most users, a single run is more than sufficient. For those chasing the cleanest possible neutral base, double distilling is a useful refinement step.
Redistilling is also an excellent way to reclaim alcohol that you no longer wish to drink.
This may include:
The Pure Distilling Reflux Condenser is designed to strip flavour and produce a high-strength neutral. In many cases, running old spirits back through the system will remove most of the original flavour and return the alcohol to a neutral base.
It is important to understand that heavily flavoured products, particularly red wines with high tannin levels and residual sugars, can be more difficult to neutralise completely. However, repeated runs will progressively reduce flavour carryover.
A common question is whether to filter before or after the second run.
The answer depends on your intended use.
If your goal is to dilute your spirit below 50% and flavour it immediately, filtering after the second run is the simplest approach. This produces a very clean final neutral ready for essences, barrel chunks or other flavourings.
If you want greater flexibility, you may choose to filter first and then redistil.
Every time the reflux condenser runs, it produces spirit at roughly 93% ABV. By filtering first and then redistilling, you create a high-strength filtered neutral base. From there, you can:
This approach gives you more options before final dilution.
Aging spirit at higher strength produces a different result compared to aging at 40%.
Higher ABV extracts flavour and tannins from wood much more aggressively. While this can produce bold results, it can also lead to over-oaking if left too long.
As a general guide, if you would normally age at 40% for 12 days, you may only need around 6-7 days at higher strength. Be sure to monitor closely and taste as you go.
Also remember that filtering after aging will remove much of the flavour you have extracted, so plan your process accordingly.
When redistilling high-strength neutral, there is a maximum limit to consider.
You should not redistil more than approximately 5.5 litres of 93% spirit in a single run. Exceeding this can result in an ethanol concentration that is too high inside the boiler, which may flood the column with vapour and prevent proper reflux action.
As a general reference, this is roughly equivalent to about 12 litres of 40% spirit once diluted.
The process itself is straightforward:
If you are redistilling your own previously distilled neutral spirit, there is no need to collect foreshots again. Those were already removed during the first distillation.
If you are redistilling unknown or flavoured products, it is wise to collect and discard approximately 100ml at the start as a precaution.
Once stabilised at around 78°C, allow the unit to run normally. As the temperature approaches 80°C, switching to slow mode will increase reflux action and help extract the remaining ethanol before shutdown.
Each time you redistil, you should expect to recover approximately 90-95% of the ethanol you put into the boiler.
For example, if you redistil 4 litres of 93% spirit, you may recover approximately 3.6 to 3.8 litres at around 92-93% ABV.
Some loss is normal and expected.
Using the Pure Distilling Output Cooler can help reduce evaporation loss by lowering the temperature of the spirit as it exits the condenser.
With a pot condenser, double distilling is typically part of the normal process. A stripping run is followed by a spirit run, and sometimes even a third run.
With a reflux condenser, much of that refinement happens internally during a single run. The column continuously cycles vapour and liquid to produce a clean 93% neutral base.
Redistilling with a reflux system is therefore an optional refinement tool rather than a necessity.
Double distilling with the Pure Distilling Reflux Condenser is not required for a clean, drinkable spirit.
However, it is a simple and effective way to increase smoothness, further refine neutral spirit, reclaim old alcohol, and create flexible high-strength bases for aging or botanical work.
For most users, one run is more than enough. For those who want the cleanest possible neutral or maximum versatility, redistilling is a valuable technique.
As always, the choice comes down to the result you’re chasing. Check out the below video which goes over this topic in detail!