Why does ABV remain the same without restabilizing?

[GrassHopper]

I am puzzled as to why when I am running a reflux column I can shut down in the middle of a run
and then when I return a day later and start up again I can still pull 93% ABV without having to
stabilize the column again?
I run a 2" CCVM, packing is copper scrubbies.
I started up the next day again just the way I left it the day before with the RC
open to the output and just let it start flowing and to my amazement, I was still pulling 93% ABV.

To me, I am basically just running in pot mode by not restabilizing and should be pulling around 60%. What am I missing? If this has been discussed, sorry, I do not know how to find it.

[Mikey-moo]

I run a 2" CCVM, packing is copper scrubbies.

How high is your packed column and how well insulated is it?

[still_stirrin]

Once you've "stacked" your column and drawn off the fores and heads, then you should be clear of them, even if you shutdown and restart later. A VM (CCVM too) will compress the tails to the end as well, so when you restart later the tails are still there...just later.
ss

[Kegg_jam]

I know DAD was promoting short stabilization times for a while.

Have you ever done a run on that rig without stabilizing? Maybe it will pull 93% from the get go anyway...

I know my 2" will pull 93 with no trouble at all but getting to 95 requires I slow it down some with a short stabilization period.

[MitchyBourbon]

Once you've "stacked" your column and drawn off the fores and heads, then you should be clear of them, even if you shutdown and restart later. A VM (CCVM too) will compress the tails to the end as well, so when you restart later the tails are still there...just later.
ss

That makes sense to me.


I usually don't get evolved in discussions like this cuz I have not run a reflex column in very long time. But looking back I have experienced the same thing. At the time I didn't think much of it, why look a gift horse in the mouth. Seems reasonable.

[Mikey-moo]

Once you've "stacked" your column and drawn off the fores and heads, then you should be clear of them, even if you shutdown and restart later. A VM (CCVM too) will compress the tails to the end as well, so when you restart later the tails are still there...just later.
ss

So use the CCVM head to take off the fores and heads... shut down... switch out to the pot still head and make the smoothest whiskey this side of the Pacos!

[Hound Dog]

Once you've "stacked" your column and drawn off the fores and heads, then you should be clear of them, even if you shutdown and restart later. A VM (CCVM too) will compress the tails to the end as well, so when you restart later the tails are still there...just later.
ss

So use the CCVM head to take off the fores and heads... shut down... switch out to the pot still head and make the smoothest whiskey this side of the Pacos!

Actually draw the fores and heads off slow, don't shut down but back your coil up for less reflux and draw off faster. This helps draw up some tails to smear into the hearts like a pot still would to add some flavor. You can run a LM in the same way, by speeding up takeoff to reduce reflux and smear in some tails. This will come off at a slightly lower proof. It is a balancing act because you still have concentrated tails at the bottom of the column you are drawing off of.

[still_stirrin]

+1 Hound Dog.

Start..stack..draw off fores + heads and pull the reflux condenser out to let it run like a potstill. Of course, you'll have to reduce heat input so you don't flood your product condenser.
ss

[BayouShine]

I am puzzled as to why when I am running a reflux column I can shut down in the middle of a run
and then when I return a day later and start up again I can still pull 93% ABV without having to
stabilize the column again?
I run a 2" CCVM, packing is copper scrubbies.
I started up the next day again just the way I left it the day before with the RC
open to the output and just let it start flowing and to my amazement, I was still pulling 93% ABV.

To me, I am basically just running in pot mode by not restabilizing and should be pulling around 60%. What am I missing? If this has been discussed, sorry, I do not know how to find it.

Hopper, you and I run basically the same rig. I run consistantly in the 93-94% range as well, with very little equalizing time.

I'm going to assume that you're running the RC if you're pulling 93%. Even though you have the "valve" open, the RC is still condensing a portion of the rising vapor and sending distillate down the column to be refluxed back up. You're not sending 100% of the vapor to the PC.

To truly be in potstill mode, you'd have to pull the RC and cap the top.

I hope this helps clear things up a bit.

[GrassHopper]

Mikey, my column is 30" packed and no, I don't have any insulation.

I am puzzled as to why when I am running a reflux column I can shut down in the middle of a run
and then when I return a day later and start up again I can still pull 93% ABV without having to
stabilize the column again?
I run a 2" CCVM, packing is copper scrubbies.
I started up the next day again just the way I left it the day before with the RC
open to the output and just let it start flowing and to my amazement, I was still pulling 93% ABV.

To me, I am basically just running in pot mode by not restabilizing and should be pulling around 60%. What am I missing? If this has been discussed, sorry, I do not know how to find it.

Hopper, you and I run basically the same rig. I run consistantly in the 93-94% range as well, with very little equalizing time.

I'm going to assume that you're running the RC if you're pulling 93%. Even though you have the "valve" open, the RC is still condensing a portion of the rising vapor and sending distillate down the column to be refluxed back up. You're not sending 100% of the vapor to the PC.

To truly be in potstill mode, you'd have to pull the RC and cap the top.

I hope this helps clear things up a bit.

Thanks to you all for the input. I just try to imagine if I was a vapor molecule traveling through copper heaven, what would I be tempted to turn into?
Bayou, yes, I am still running the RC the next day, but wide open to the output. What you say seems to make sense. I didn't think I would be getting any reflux when wide open. I just might have to try out (removing the RC completely), capping the column and then running in pot mode and see what happens. There must be a law here that states you can only achieve 93% with a stacked column or some theoretical event......even if you only have a certain ratio of alcohols left in the boiler. I know I didn't pull all the hearts out because I ended up with almost a gallon more the next day before getting into the tails.
StillStirrin, I don't understand how I could start the next day with 93% just because the fores and part of the heads were removed without some reflux as Bayou stated. Just trying to understand the science/theory of it all.

[BayouShine]

Bayou, yes, I am still running the RC the next day, but wide open to the output. What you say seems to make sense. I didn't think I would be getting any reflux when wide open. Even though you're running the valve wide open, you're still running a 1:1 reflux ratio, assuming your output is the same diameter as the column itself. As long as the RC is in there and running, you're going to have reflux.I just might have to try out (removing the RC completely), capping the column and then running in pot mode and see what happens. There must be a law here that states you can only achieve 93% with a stacked column or some theoretical event......even if you only have a certain ratio of alcohols left in the boiler.The boiler charge in this case is meaningless. Example, if we had a 10% birdwatchers wash or 40% low wine, you're still going to run at that 93% mark for that particular takeoff rate. What will happen though is the run with the low wines will take longer because there's more alcohol in the boiler. I know I didn't pull all the hearts out because I ended up with almost a gallon more the next day before getting into the tails.

StillStirrin, I don't understand how I could start the next day with 93% just because the fores and part of the heads were removed without some reflux as Bayou stated. Just trying to understand the science/theory of it all. As far as starting back up and running 93% right off the bat, that's what you're column is supposed to do. The packing is what increases the ABV, not equalizing. Equalizing separates the fractions and define the cuts that need to be made.

I hope this is helping you out and not confusing you more.

[skow69]

It is the mingling of uprising vapor with downflowing reflux that increases purity. The packing is there to slow things down and promote more mingling. Feel the column next time you run it. You will find it reaches distillation temperature at the bottom first. Then the hot zone climbs slowly up to the top. For that period of time you are in full reflux. The hot vapor condenses just above the hot zone and runs back down through the packing, mingling with vapor on the way.

Once it is up to temperature a VM, any VM, has a minimum reflux ratio of 2:1, which means that at least half of the vapor is always being refluxed. And that is only possible if the takeoff pipe is the same size as the column and the "valve" is fully open. If you have a 1" takeoff on a 2" column your minimum r.r. is about 5:1, or 4 parts reflux to 1 part takeoff. Your ABV is up because of all the reflux you are getting that you didn't know about.

EDIT: I just read Bayou Shine's post. Consider mine just an expansion of what he said.

[bluefish_dist]

As stated above you get reflux prior to the vapor getting to the takeoff. I run plates under my column and you can see the reflux as the column is heating up. It also depends on heat. If you throw a lot at it, the vapor gets pushed up the column faster and less reflux, more stabilization time will be needed. If the heat is lower, the vapor slowly moves up the column and will be almost stabile by the time it reaches the top. On mine I maybe see a .2 deg temp change if I bring it up to temp at my running heat input.