Distilling heads to neutral grain spirits

[Tennessee_Spirits]

I saved this project until I had collected 5 gallons of heads. I always discard the fore shots so I knew there was nothing truly toxic in them and they measured 185 proof.

What I was looking for was high proof tasteless alcohol to make liqueurs. My first attempt was with a 3 gallon boiler and Mile High distilling column packed with one roll of copper and the rest of the column (about 12") in Raschig rings. The product was distilled at 45% ethanol and I got 3 liters of 95% product with almost no taste. Taste is a sense that is logmatic, so the range of tasting is very wide. I used this NGS to made cordials with various fruits and could not detect any heads taste in the final product.

The resolution of a still depends upon the number of theoretical plates. (If someone knows how to determine the relationship of Raschig rings and plates please respond). Plates are traditional as they map to the commercial world's columns. Diameter of the column is important to scale of production but larger columns reduce the resolution ability of a distillation. Height increases resolution. Raschig rings produce more points of vapor/liquid equilibrium in the column.

The question I faced was could I lengthen the column and add more Raschig rings without obstruction to the system and potential of explosion and would the rate of production be enough I could tolerate at hobby scale? I used the adapter with a pressure relief valve.

I added 12" extension to my 2" diameter column by Mile High mini which gave it an effective 24" of small Raschig rings. I found it very satisfactory. Output was adequate for a 8 gallon boiler and the run took 3.5 hours and there was 200 ml of heads (really strong heads) and the hearts were 95% ethanol with no taste. I asked several people to taste it and none detected anything. I was amazed that tails were not worth collecting. As soon as the product went below 90% ethanol the stillhead temperature rose rapidly so that I had 200 ml of tails.

I still wonder how this would work with a 3" column packed with twice as many Raschig rings and a column probably 6 feet high.

[bluefish_dist]

I think what you are asking is HETP or height equivalent theoretical plate. I am too lazy to look it up, but I think rings are between 5 and 6”, so a foot is about 2 plates. For purity, more height = more plates = higher purity. Supposedly you need 15 plates to reach azeo. The more plates you add up to approximately 40 the easier and faster it is to hit azeo.

I have tested scrubbies and they have a HETP of 4”. Marbles were slightly more.

Diameter increases speed. For a column, area is proportional to output. A 3” is about double a 2”. 4” is almost 4 x a 2”. 6” is double a 4”.

You can also increase output by adding height. As you get taller the column can run at a lower reflux rate to get the same abv allowing it to run faster.