Home Distiller

Hi!
Your reflux still has a vapor temp that is optimal. Every still is a bit different, but every one has a "golden" temperature. Exceed that temperature during a run, and you're going to get smearing. The easiest way to exceed that temperature is to draw too much. Every drop that comes out your product valve is a drop that isn't available as reflux that will drop off of that bottom plate and help clean up your drink. You need to figure out what that temperature is for your still. Best way is to set up a run with your normal parameters, draw off your fores and pull as little product as you can into small jars - we're talking drip rates. Whatever temp gets you the highest ABV is your still's optimum temp.

My 2" Boka, packed with copper mesh, can get about 300 ml/hour without exceeding that temperature, but every still is different. I've got 3 liters of SPP that's going into my still in a couple of weeks in an attempt to increase my draw rates for this season's still runs. It could allow me to triple my draw rates without a loss in quality. We'll see.

If you're running a reflux still, you need that temperature to be reliable and you need to watch it. When I do a run, I collect in pint jars, about 3/4 full, and every time I change a jar, I note that top temp in my run log. I also run a hydrometer reading on each jar. I use a k-type thermocouple connected to an industrial monitor that has the temp in big, red LEDs and also puts out an RS-232 signal to a laptop, so I can have an automatic log as well as alarms. It's that important to me.

As the run continues, that vapor temperature will increase. You can get it back down by either increasing the power to your heater element (more power will mean more condensed reflux back running back into your column), or cutting back on your draw (same thing). Once you can't control that temperature any more, you're going to start filling your feints jar.

That's how i do it. Hope that helps.

"As the run continues, that vapor temperature will increase. You can get it back down by either increasing the power to your heater element (more power will mean more condensed reflux back running back into your column), or cutting back on your draw (same thing). Once you can't control that temperature any more, you're going to start filling your feints jar."


I would say that using heat to control reflux can either increase or decrease head temp/abv. It depends on which side of optimal you are operating. This is not an absolute one way or the other.
If you are well below optimal speed/heat input adding more heat will raise abv/lower head temp as you can be depleting the alcohol in the column to quickly and adding more will help. I find I rarely operate in this condition.
More commonly I am pushing as much product as possible and lowering heat will stop pushing water up the column and increase abv/lower head temp. The way I usually run is to try and hold 20fps vapor speed, then once I reach a max reflux or minimum number of turns on my vm valve I will back off heat to get the last bit of alcohol out at azeo. Once I cant hold a lower head temp and have reduced power significantly I shut down.

I can see this in my whites as well running three plates. I take off heads at 8000w, then up the heat to 12,000w. Head temp goes from 168 to 172 with the addition of the 4000w. These temps correspond to about a 10 proof decrease. I am sure if I was running down around 4000w at the same takeoff adding heat would have the opposite effect.