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Re: Why is it necessary to take cuts using a reflux still??

PostPosted: Wed Mar 01, 2017 6:30 pm
by ed9362
Ed9362. Why don't you whack a whopping great handful of pure sodium chloride into a small sample of your grog when you get out of your car at the lab to 'denature' it and then take it in for the gas chromatograph? Just disregard any Na and Cl hits. Shouldn't affect any of the alcohol components too much short term.

to be honest im not sure how the lab people would react if I asked them to run alcohol through one of their machines. I do have access to an ADA which I could run through I guess, it would give an idea about what is in the product but not ratios.

I might give it a go in a few months, we have union problems at the moment and the company will use any excuse they can to fire us

Re: Why is it necessary to take cuts using a reflux still??

PostPosted: Thu Mar 02, 2017 7:33 pm
by Kenster
moon, lucky you... some really great, constructive responses...that is how we all learn.
Just my 2c...if you keep your col in reflux for much longer (maybe an extra 30min) before you take off fores, the fractions 'should' stack a bit more and the theory will prove closer to the mark. There will always be smearing to some extent with our smaller home systems (yes ex T500 user also) so after fores, reflux some more and take off super slow. I know it is a drag hangin for ages through a run but slow is often a cleaner run.

Re: Why is it necessary to take cuts using a reflux still??

PostPosted: Fri Mar 03, 2017 3:27 pm
by moonshineman99
warramungas - You lost me completely after 'Pure substances have specific boiling points. Not mixtures of substances. They have a 'range' somewhere between the lowest and the highest.' But I get what you are saying that a mixture of different impure alcohols come through throughout the distill, not just at the temperatures listed.
Cheers :handgestures-thumbupleft:

Re: Why is it necessary to take cuts using a reflux still??

PostPosted: Fri Mar 03, 2017 3:29 pm
by moonshineman99
Pugdog1 - Thanks buddy, that was helpful :D

Re: Why is it necessary to take cuts using a reflux still??

PostPosted: Fri Mar 03, 2017 3:31 pm
by moonshineman99
Thanks fellas, a lot of that makes sense now that it is explained! :music-deathmetal:

Re: Why is it necessary to take cuts using a reflux still??

PostPosted: Tue Mar 07, 2017 8:22 am
by mattcoffs
For the sake of a few bucks, why not make two TPW batches and run them separately?

Don't cut the first.
Cut the other, taste and smell each jar. You'll know in about 5 jars why you should cut it...

You'll also find that those numbers are likely based on lab conditions, real world just isn't like that.
Sometimes, especially with rum washes i'll be reading 82/83 but still be pulling good hearts. Other times, not so good. All comes down to your ferment.

I've found sometimes that the more sh*t you read on the internet the more confused you get, sometimes you've just gotta experiment for yourself. Hands on is sometimes a lot easier than endless research.

Plus, internet forums are like ars*h*les, every f***er has one :))

Re: Why is it necessary to take cuts using a reflux still??

PostPosted: Tue Mar 07, 2017 1:04 pm
by Minpac
OP- what warramungus is referring to is the azeotropes - when substances are mixed, their combined boiling points can be higher or lower than the individual boiling points.
There's a list of some known ones here:
https://en.wikipedia.org/wiki/Azeotrope_tables

The most common reference to azeotrope on distilling sites is about water-ethanol azeotrope. This azeotrope is why you can't pull 100% ethanol out of a still despite water boiling at 100, the combination boil point is 78.4 degrees C It's often referred to as getting the highest purity out of a still.

The list of azeotropes includes mixes with water, mixes with ethanol, mixes with methanol, and I'm sure there are others.

Yeasts produce a heap of stuff -I've attached a pic of their digestive inputs/outputs:
•CO2
•acids (organic/fatty)
•Ethanol and higher alcohols (fusel oils)
•Esters (reactions of acids and alcohols)
•aldehydes(oxidised alcohols) & ketones
•sulfur containing compounds
Some of these are likely coming out in the boil too.

got this from the below. It's about beer, but the process is mostly the same:
http://www.craftbrewersconference.com/w ... _Meyer.pdf

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This post is as much for my future reference - sorry if it's beating a dead topic :)

Re: Why is it necessary to take cuts using a reflux still??

PostPosted: Thu Oct 18, 2018 7:10 am
by Jimmy.
Do people then throw the cuts from the heads and tails back into the next batch?

Do you have a certain size you usually cut at? Ie a 25L wash people do cuts every 100ml?

Re: Why is it necessary to take cuts using a reflux still??

PostPosted: Thu Oct 18, 2018 11:22 am
by Sam.
Jimmy you can either throw them in the next run or save them up and do an all feints run.

Smaller amounts you collect in will help determine cuts better and gain you more hearts.

Also drop into the welcome center for a quick intro if you can please :handgestures-thumbupleft: