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Full Reflux ?

PostPosted: Fri Dec 01, 2017 2:35 pm
by prawnz
Quick question for the wise if anyone is about at the moment .

How long should I hold at full reflux ?

Its been there for about 25 min now and is holding nicely , so the column is well hot , the RC cooling is going at about 1 lt per minute and the head of the column is steady at 25c .

I'm thinking an hour if it will hold there ?

Cheers Al

Re: Full Reflux ?

PostPosted: Fri Dec 01, 2017 2:44 pm
by EziTasting
When you read the post in the Newbies section, it mentions to do it for an hour.

I do it for an hour - not because I know any better or that I am a trusting fool, just had no justification to do it any shorter!

There are a number of people here that do it for less, I've read one person did or does it only for 30 mins ... but again, no justification as to why (I am guessing they think its OK and it saves them time)...

The purpose of reflux is to separate the different alcohols by repeated evaporation and condensing, the more volatile will end up higher in the column than the less volatile... as a mixture, the different alcohols DON'T evaporate off as they do when a single alcohol (chemistry - how they react together).

So, logically, the longer you leave it in reflux, the clearer the separation... just keep in mind that they can "smear" in the parrot, so you might have to drain the parrot each different layer ... if you wanted perfect separation!

Re: Full Reflux ?

PostPosted: Fri Dec 01, 2017 3:01 pm
by prawnz
Cheers Eazy , was kinda what I was thinking , just wanted to hear someone else say it . :handgestures-thumbupleft: :handgestures-thumbupleft:

No parrot here unfortunately just a glass tube that I fill up every now and the for curiosity sake .

Re: Full Reflux ?

PostPosted: Fri Dec 01, 2017 3:18 pm
by EziTasting
prawnz wrote:Cheers Eazy , was kinda what I was thinking , just wanted to hear someone else say it . :handgestures-thumbupleft: :handgestures-thumbupleft:

No parrot here unfortunately just a glass tube that I fill up every now and the for curiosity sake .

:handgestures-thumbupleft: all good.

Someone else will chime in perhaps with more information

Re: Full Reflux ?

PostPosted: Fri Dec 01, 2017 5:54 pm
by Huntsman96
I reckon you hit it head on Ezi. On all the boka runs I tried to do an hour of stacking and on those where i did 30 minutes i found i got more smearing of heads and hearts.

Re: Full Reflux ?

PostPosted: Fri Dec 01, 2017 6:04 pm
by prawnz
Yep , did an hour and I can already pick the heads to hearts cut I reckon .

I'm a bit over 5 hours into this run , slowest I've ever done by far . Keeping notes for the first time ever to .

I'll post them here incase anyone is running a similar still .

Re: Full Reflux ?

PostPosted: Fri Dec 01, 2017 8:03 pm
by EziTasting
Nice work! :handgestures-thumbupleft:

Re: Full Reflux ?

PostPosted: Sun Jan 06, 2019 7:20 am
by spiltdrink
Necro post.But I'm full of coffee.
This isn't in the plated column section, so.....

Holding a packed column at full reflux until it sorts it's self out and reaches what we refer to as equilibrium is different for every rig.
It is a balance between:
The type of still.ie.Lm Vm
Column diameter
Thermal mass (thermal lag)of the packing
Hetp of packing
How much packing
How much power being thrown at the boiler
The temperature of the of output water of the reflux condenser ( hence the temperature of reflux)
The type of wash you have in the boiler
They are all related to each other.

If you are a noob firing up your still for the first few dozen times just sticking to the hour does the job, one less thing to worry about.

When you get to know your rig a bit better it's just another area in distilling to refine.The aim here is to reduce time while continuing to get a quality product.After spending hundreds of hours next to your still, waiting unnecessary starts to feel like a waste of time.
Experiment, shave off 5 min and record the results. When you get smearing, wind it back a bit. This is time saved every time you fire up your still, forever. It's not compounding interest, but it adds up all the same.

I have one (very specific) rig that takes 25 min to reach equilibrium.
I still once a week, in just one year I save 30 hours (more than three full working days of time) just by a little experimenting.
I can use that time to: experiment with ferments, do stripping runs, clean my equipment, write long winded posts, the sky's the limit!!!

Just something to chew over while you're sitting next to your still

Re: Full Reflux ?

PostPosted: Sun Jan 06, 2019 8:32 am
by The Stig
The only thing I will add to spiltdrink post above (very good post) is:
Different wash's require different times as well even when doing "the same wash" it will differ from mix to mix and even more so between summer and winter.

Re: Full Reflux ?

PostPosted: Wed Jan 09, 2019 9:33 pm
by EziTasting
spiltdrink wrote:...I can use that time to: experiment with ferments, do stripping runs, clean my equipment, write long winded posts, the sky's the limit!!!

Just something to chew over while you're sitting next to your still



:laughing-rolling: :laughing-rolling: Gold!!

Great post!

Re: Full Reflux ?

PostPosted: Thu Jan 10, 2019 2:17 am
by hillzabilly
I think how much power you are using may effect this ,with the 4inch still I started using 2400wt and yes an hour had it settled out well ,but when I used 3600wt it seemed ta get sorted quicker by 15mins ,maybe larger volume(more power) of reflux the quicker it can settle.cheers hillzabilly :think:

Re: Full Reflux ?

PostPosted: Fri Jan 11, 2019 12:35 pm
by YarraRanges
With 14 plates I can pick no difference between 30 minutes and 1 hour. I now do full reflux for 30 minutes with rum and TP washes. They always end up very clean.