Distillation theory question - cleaner more neutral spirit or dirtier/smeared spirit

[nuddy]

Hi everyone, long time reading first time poster.

I have a question to ask regarding distillation theory and reflux/smearing. Specifically the difference in spirit quality while running a still at a set output speed off the parrot, using two different heat/power settings and their corresponding cooling water settings. i.e. A low heat and low cooling water flow setting, then a higher heat and higher cooling water flow setting.

For this example we're using a 4" hybrid column with 4 bubble plates, dephlegmator and product condenser, with the boiler charged with a rum wash at 10% abv, aiming to do a single one and done run to create the rum new make spirit. For both scenarios aiming to run the still at a set output of 2.0 L/hr off the parrot.

Once out of the fores and into the hearts, the controls are set on the still to provide a low boiler heat/power input and its corresponding cooling water flow to the dephleg to control the output speed off the parrot to 2.0 L/hr.

If the power/heat into the boiler was then set higher (lets say 1.5 x higher) with the corresponding cooling water flow to the dephleg to ensure output speed at the parrot is maintained at 2.0 L/hr.

Would this increase result in a cleaner more neutral spirit? As there is more turn over of liquid and vapour within the column, essentially higher flow rate of vapour, more interaction between vapour and liquid, more reflux occuring, better separation of more volatile compounds. 

Or would this result in a dirtier or more smeared spirit as the extra energy in the column results in pushing a portion of the heavier compounds up earlier than they naturally would. e.g earlier arrival of tails.

Or is it a combination of both, an increase in power/heat initially results in providing a cleaner more neutral flavoured spirit up to a certain point where it reaches a tipping point if too much power/heat is applied even with corresponding cooling, then it would then start to cause smearing?

Keen to hear the thoughts from the more experienced on here.

 

[Kindred Spirits]

Hey Nuddy, welcome to the forums.

So since you would be keeping the output the same, you would be increasing he amount of reflux in the column which should give you a higher output ABV and a cleaner spirit. 

Typically the slower the takeoff with refluxing occurring on all plates the cleaner the spirit and higher the ABV as the "heavier" components are pushed back lower in the column.

[Pofarmer]

So I think the answer to what you're doing is "It depends". It depends on the capacities you have available. I'm running a 4" 4 plate column on a 55 gallon set up with 11000W available heating. 2L per hour for a 4 " column, in my mind at least, is low. the "ability" of the column is probably around double that. I've pushed my column to 8L or around 2 gallons per hour. That's running around 9500 Watts. This was on a bourbon mash. The resulting spirit, once you get past the heads, which was really compressed and really quick, wound up being a little tailsy throughout the entire run. It's sitting in stainless now and I intend to do a second pot still run slower in an attempt to clean it up a little.  In retrospect I should have been running a little more dephleg, and my column was trying to tell me that(Didn't have a vigorous boil on the bottom plate)but I'm still learning too. We'll see. I've had a little dab on oak, and it's not bad. There is another larger distillery near me that strips in a 500 gallon steam jacked still with a 12inch, 4 or 6 plate column, can't really recall.  On a stripping run he'll hit as high as a gallon a minute. To me that's way too fast for that sized column, and the whole thing has a tailsy quality that doesn't come out in a spirit run. I think he's actually making esters or conjoiners by overheating the wash, but that's I guess, a little different topic. So, I guess, long story short, I think you can certainly over run your column, but I doubt you have anywhere near enough power available to actually do it.