Water Temperatures For Condensers?

edited February 10 in Usage


  1. What water temperatures at the inlet and outlet of the dephlegmator do you recommend?
  2. What water temperatures at the inlet and outlet of the condenser do you recommend?
  3. I wanted to limit the temperature at the level of the aromatic tank and I used the dephlegmator. Unfortunately, the result was not there: the temperature at the level of the tank was much higher than the temperature of the water leaving the dephlegmator. How is it possible?

Thank you so much,



    1. Ideally, anywhere between 10° C and 15.5° C is probably a good place to be for inlet temps. Outlet temps have a direct relationship with ABV unless your vapor speed is so fast that the heat exchange process lacks dwell time.

    2. Same as above for inlet temps (though not a rule or anything). Outlet temps seem more academic. Typically you'll shoot for the resulting distillate to be cool to the touch, though not a requisite. Distillate @ 15° C is ideal, and you'll prefer that the lower 2/3 of your condenser be somewhat cool to the touch.

    3. Aromatic tank? Can you repeat the question a bit differently?

    StillDragon North America - Your StillDragon® Distributor for North America

  • Sorry: I wanted to try to control the temperature of the vapors which are measured just before the aromatic tank. the idea was to prevent the temperature of these vapors from being too high in order to avoid extracting too much essential oils. thanks again @Smaug

  • Interesting comments.

    I was testing my 60L LM build the other day and was noting water temperatures during a strip run with beer at 5% ABV.

    Water into my RC was at 21 deg C which thereafter flowed to my PC and then exited out at 31.2 deg C. (This water inlet temp is obviously too high and need to get it down but this is the municipal water temp at this time of the year).

    Other info, 5.1KW, temperature of column vapour at distillate takeoff 93.5 deg C and distillate from take off was at approx 57 deg C and distillate after PC was at 29.3 deg C.

  • the question I ask is for what purpose...

    For safety, the inlet of the Product Condenser should be below an unsafe temperature.

    For Efficiency, the Reflux Condenser inlet temperature should not be 'too cold' as to cool the liquid it condenses.

    Beyond that, it really depends upon your method of providing the cooling water.

    If by 'aromatic tank', you are talking about the "vapor space below the Reflux Condenser" being warmer than the water exiting the Reflux Condenser, this is probably due to too small of a Reflux Condenser or too much power in the boiler.

    Chances are your temperature sensors are not telling you the whole story, they are not telling you the temperature inside the vapor chamber, they are telling you the temperature at one tiny point in the vapor chamber.

    I prefer to measure the temperature inside the Reflux Condenser, but if you have good flow, you can measure the exit water temperature like you are doing... the flow rate multiplied by the temperature increase of the water is the the amount of heat you are taking out of the column. you can monitor the temperatures above and below the Reflux Temperature as a guide, but if you try to shoot for a certain temperature, and are not in a precision controlled industrial environment that was purpose designed and that spends a lot of time calibrating, you will go crazy. running a different proof charge, different ambient temps different cooling water temps, all affect the temperature below the Reflux Condenser. More importantly, I find that changes in your temperatures above and below the reflux temperature are the biggest indicator of what is going on.

  • Aromatic tank = Gin basket ???

  • If 'aromatic tank' is the gin basket, then @jean needs to remove the Reflux condenser or turn it off... You need to run the full range of temperatures(alcohol strengths) through the aromatics... It has been written on this forum multiple times that substandard results come from not running the full array of vapors through the botanicals.

  • Thank you ar all @richard yes, gin basket

  • Not to try and take away from the OP but I can’t get water under 23deg, but have enough flow to keep the outlet cool. Is the safe temperature that @CothermanDistilling refers to purely from a flammable vapor point of view? I’m not in a race so can turn down heat input to assist.

  • Sure. Cooling media temps can be marginalized by flow rate. Slower flow rates can be deceptive as Cotherman alludes. Very slow flow rates can minimize the mixing of cooling media and create a channeling affect that prevents full utilization of your surface area.

    StillDragon North America - Your StillDragon® Distributor for North America

  • With a big (oversized even) product condenser, you can slow the water down and still get product out at the input temperature or within a tenth of a degree and run relatively slow... or you can run fast... In my case, I run very slow for the other part of our cooling system (radiators w/ fans and 1000L reservoir), which works best at removing the heat into the air outside the building if the incoming temps are high and the flow rate is low... but for other folks, running fast may be better

  • Interesting thanks for the info. I come from a background working with heat exchangers, and I’ve always run as fast as possible before hitting the efficiency cliff for pumps & fans. This assumes a matched condenser for the heat input, and I’m well oversized there. I’ll experiment.

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