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DIY condenser/Liebig question
Posted: Sat Aug 28, 2021 8:47 am
by PeatyKeats
I am still a novice, so I thought this would be a good place to ask a novice question. I apologize if I’m wrong.
At the well-intentioned urging of this forum, I’ve been practicing some beginner soldering, and want to build my own Liebig condenser. I’ve come across different plans/vids both here and other places. The following is a straightforward setup that echoes what others have done.
https://www.instructables.com/Liebig-Condenser/
I’ve also read that a Liebig this narrow (1” water jacket of a 3/4”-1/2” vapor pipe) may have some trouble knocking down vapor.
My question is, can I build a Liebig that has a 1/2” Copper pipe for condensing with a 1 1/2” water jacket, according to these basic specifications WRT length & construction, and successfully condense the vapor off a 13 gallon milk can boiler with a 2” X 24” copper riser?
For a little background, I’m planning to focus on fermenting/distilling single malt whiskey (mostly peated). I’ve been looking at various recipes, mostly Jimbo’s AB single malt, although I plan on fermenting off the grain and adjusting the overall amounts to fit in w/ his ratios of 2 lbs grain per 1 gallon water.
Sorry if I left anything out. Thank you for any responses.
Re: DIY condenser/Liebig question
Posted: Sat Aug 28, 2021 9:33 am
by jonnys_spirit
3/4 over 1/2 x 48” works very well to knock down everything my 5k5w element can throw at it. All the cooper is available at the hardware store too.
Good luck!
-j
Re: DIY condenser/Liebig question
Posted: Sat Aug 28, 2021 10:19 am
by NormandieStill
Knock-down capacity needs to match the heating element (electric or gas) not the size of the boiler. A patient distiller could run a well-insulated 200L pot still on a 2kW element with a tiny liebig, but they'd be at it for a while!
There's a handy calculator on the parent site that will get you into the ballpark. As I understand it, it errs on the side of conservatism, so if you build to the calculated dimensions you'll probably have capacity left over... which is never a bad thing!
Re: DIY condenser/Liebig question
Posted: Sat Aug 28, 2021 10:23 am
by Setsumi
jonnys_spirit wrote: ↑Sat Aug 28, 2021 9:33 am
3/4 over 1/2 x 48” works very well to knock down everything my 5k5w element can throw at it. All the cooper is available at the hardware store too.
Good luck!
-j
+1 on 3/4 over 1/2... 800mm lenght should be enough but for that extra jonny is correct... length is never to look down on. But you do not need a larger shell, it adds wheight and do not contribute to flow speed.
Re: DIY condenser/Liebig question
Posted: Sat Aug 28, 2021 10:33 am
by PeatyKeats
Thank you for those replies.
I knew I missed something.
At first, I’ll be distilling with a 20,000 BTU adjustable propane burner (outdoors).
Thanks for the information. I appreciate it.
Re: DIY condenser/Liebig question
Posted: Sat Aug 28, 2021 10:47 am
by Saltbush Bill
There is nothing wrong with 1 inch over 3/4..... it works fine.
Re: DIY condenser/Liebig question
Posted: Sat Aug 28, 2021 11:10 am
by jonnys_spirit
Saltbush Bill wrote: ↑Sat Aug 28, 2021 10:47 am
There is nothing wrong with 1 inch over 3/4..... it works fine.
I’ve used a 1” over 3/4” for an RC / vertical liebig and also like that the 3/4” vapor path decreases vapor speed and increases dwell time with a similar sized water jacket - compared to 3/4 over 1/2. I’ve upgraded to a shotgun that i’ll be putting into service soon and am looking forward to a further increase in dwell time and reduced length.
In any case a liebig is easy to DIY, economical, and works very well. I’ve made a few.
I used a 3/4 steel bit (or a 1” stepper bit) to take the stop out of the tee. Much easier than a file or dremel the last couple I made.
Cheers!
-j
Re: DIY condenser/Liebig question
Posted: Sat Aug 28, 2021 11:24 am
by Saltbush Bill
jonnys_spirit wrote: ↑Sat Aug 28, 2021 11:10 am
I used a 3/4 steel bit (or a 1” stepper bit) to take the stop out of the tee. Much easier than a file or dremel the last couple I made.
Yes much faster and easier.
Re: DIY condenser/Liebig question
Posted: Sat Aug 28, 2021 12:58 pm
by greggn
PeatyKeats wrote: ↑Sat Aug 28, 2021 10:33 am
At first, I’ll be distilling with a 20,000 BTU adjustable propane burner (outdoors).
Then you'll be safer with a long liebig that puts the product output further away from an open flame.
Re: DIY condenser/Liebig question
Posted: Sat Aug 28, 2021 1:10 pm
by PeatyKeats
greggn wrote: ↑Sat Aug 28, 2021 12:58 pm
PeatyKeats wrote: ↑Sat Aug 28, 2021 10:33 am
At first, I’ll be distilling with a 20,000 BTU adjustable propane burner (outdoors).
Then you'll be safer with a long liebig that puts the product output further away from an open flame.
I promised my wife that I wouldn’t blow up,
1) Our house
2) Her or our children
3) Myself
Re: DIY condenser/Liebig question
Posted: Sun Aug 29, 2021 3:59 pm
by S-Cackalacky
I've made two liebig condensers. I crimped the vapor tube in both cases. One was a 1" PVC jacket with 1/2" copper vapor tube. The second was pretty much the same, but with a 1" copper jacket over 1/2" copper vapor tube. The jacket length of both was about 28". Crimping is said to improve the vapor knockdown ability by creating turbulence of both the cooling water and the vapor.
Word of caution - don't make the crimps too deep. It can create an obstruction and cause back pressure. Put a metal rod inside the pipe to avoid making the crimped space too narrow. Alternate the crimps by 90 degrees and space them about 1/2" apart.
Anyway, just a means of cutting back on the overall length of the liebig if that's an issue.
Re: DIY condenser/Liebig question
Posted: Sun Aug 29, 2021 4:20 pm
by Saltbush Bill
The crimp marks also need to be in the vertical position when the condenser is assembled and in use......horizontal crimps will or can lead to pooling and smearing.
Re: DIY condenser/Liebig question
Posted: Sun Aug 29, 2021 5:11 pm
by Corn Cracker
I got my design from this forum, it is ¾ over ½ hooked to a 20g pot and knocks all vapor down no problem.
The 2 tricks i picked up and used are
1. spiraling a stripped copper wire around the ½ inch to force the water to swirl around it, it does a good job, it goes into the clear discharge hose in a vortex.
2. I flattened a length of ¼ inch copper tubing and partially snipped it about every inch or so to put into the ½ inch pipe, this is supposed to break up the vapor flow and force it to the sides.
Hope this helped
Re: DIY condenser/Liebig question
Posted: Sun Aug 29, 2021 5:35 pm
by acfixer69
Saltbush Bill wrote: ↑Sat Aug 28, 2021 10:47 am
There is nothing wrong with 1 inch over 3/4..... it works fine.
That was my first condenser on the pot still I built. It was a meter from water in and water out Never saw a need for the wire for turbulence as I could slow the water down and create a smooth temperature gradient up the shell with 5500 Watts no problem.
Re: DIY condenser/Liebig question
Posted: Sat Sep 11, 2021 12:22 pm
by PeatyKeats
Corn Cracker wrote: ↑Sun Aug 29, 2021 5:11 pm
I got my design from this forum, it is ¾ over ½ hooked to a 20g pot and knocks all vapor down no problem.
The 2 tricks i picked up and used are
1. spiraling a stripped copper wire around the ½ inch to force the water to swirl around it, it does a good job, it goes into the clear discharge hose in a vortex.
2. I flattened a length of ¼ inch copper tubing and partially snipped it about every inch or so to put into the ½ inch pipe, this is supposed to break up the vapor flow and force it to the sides.
Hope this helped
1) what gauge copper wire did you use to wrap around the vapor pipe? I’ve read 16 gauge should be used, but I could only find 12 gauge nearby.
2) Have you found that putting snippets of copper in the vapor pipe helps?
Re: DIY condenser/Liebig question
Posted: Sat Sep 11, 2021 2:47 pm
by 8Ball
jonnys_spirit wrote: ↑Sat Aug 28, 2021 11:10 am
Saltbush Bill wrote: ↑Sat Aug 28, 2021 10:47 am
There is nothing wrong with 1 inch over 3/4..... it works fine.
I’ve used a 1” over 3/4” for an RC / vertical liebig and also like that the 3/4” vapor path decreases vapor speed and increases dwell time with a similar sized water jacket - compared to 3/4 over 1/2. I’ve upgraded to a shotgun that i’ll be putting into service soon and am looking forward to a further increase in dwell time and reduced length.
In any case a liebig is easy to DIY, economical, and works very well. I’ve made a few.
I used a 3/4 steel bit (or a 1” stepper bit) to take the stop out of the tee. Much easier than a file or dremel the last couple I made.
Cheers!
-j
Now you tell me!!

. I just filed out the stops on a condenser I made for my gin pot. I knew there had to be an easier way.
Re: DIY condenser/Liebig question
Posted: Sat Sep 11, 2021 2:48 pm
by Sporacle

I made a 1 inch over 1/2 liebig and used 3.1mm copper wire to wrap the 1/2 and it was fairly tight between the two, not sure if it helps or not. Don't have enough power atm to really push it. Soon will though
Re: DIY condenser/Liebig question
Posted: Sat Sep 11, 2021 3:42 pm
by Yummyrum
I used 2.5mm^2 solid wire I stripped out of some old electrical cable . That worked for me on 3/4” over1/2” Aussie copper but it will probably be different for US size copper .It was a perfect fit infact almost too perfect . A bit of vege oil helps to slide it in
2.5mm^2 was a little undersized for the 1” over 3/4” but close enough for me .
A handy hint is to clamp it at one end to the inner and spiral wrap it really tightly then clamp it at other end .I use vice grips but little G clamps will work .
Then stand it vertically , paint on the liquid flux starting at the top . Then start to solder it from the top . The solder and flux will follow the spiral down to the bottom .
Re: DIY condenser/Liebig question
Posted: Sat Sep 11, 2021 9:19 pm
by PeatyKeats
Sporacle wrote: ↑Sat Sep 11, 2021 2:48 pm

I made a 1 inch over 1/2 liebig and used 3.1mm copper wire to wrap the 1/2 and it was fairly tight between the two, not sure if it helps or not. Don't have enough power atm to really push it. Soon will though
So, the copper wire you used sounds like it’s closer to 6 AWG, which, if I’m correct, makes me feel good that 12 gauge won’t be too thick.
Thanks.
Re: DIY condenser/Liebig question
Posted: Sat Sep 11, 2021 9:23 pm
by PeatyKeats
Yummyrum wrote: ↑Sat Sep 11, 2021 3:42 pm
Then stand it vertically , paint on the liquid flux starting at the top . Then start to solder it from the top . The solder and flux will follow the spiral down to the bottom .
Are you soldering the copper wire intermittently or a continuous stream, following the spiral?
I planned on soldering the end points and sporadic points inwards with the wire wrapped tight enough to get the 1” copper water jacket on.
Re: DIY condenser/Liebig question
Posted: Sat Sep 11, 2021 9:34 pm
by Sporacle
So, the copper wire you used sounds like it’s closer to 6 AWG, which, if I’m correct, makes me feel good that 12 gauge won’t be too thick.
Thanks.
Yeah mate had a quick look at sizes and that should fit fine, just follow all the pointers and it will be sweet, I went for sporadic attachment of the wire, start finish and a few mid points. Others will be able to comment on the benefits of this vs continuous solder

Re: DIY condenser/Liebig question
Posted: Sat Sep 11, 2021 10:37 pm
by Yummyrum
PeatyKeats wrote: ↑Sat Sep 11, 2021 9:23 pm
Yummyrum wrote: ↑Sat Sep 11, 2021 3:42 pm
Then stand it vertically , paint on the liquid flux starting at the top . Then start to solder it from the top . The solder and flux will follow the spiral down to the bottom .
Are you soldering the copper wire intermittently or a continuous stream, following the spiral?
I planned on soldering the end points and sporadic points inwards with the wire wrapped tight enough to get the 1” copper water jacket on.
Yeah I do continuous . … No particular reason other than I like soldering

…. And it doesn’t take that much extra effort .
But looking for a reason , if I had to file it down to fit in the shell, it would be easier if its solid soldered than slipping up and down the pipe .
Re: DIY condenser/Liebig question
Posted: Sun Sep 12, 2021 7:32 am
by S-Cackalacky
Saltbush Bill wrote: ↑Sun Aug 29, 2021 4:20 pm
The crimp marks also need to be in the vertical position when the condenser is assembled and in use......horizontal crimps will or can lead to pooling and smearing.
Just now saw this and have no idea what you're trying to describe. I use vice grip pliers to make the crimps. I position the pliers perpendicular to the 1/2" pipe. I rotate the pipe 90 degrees for the next crimp and continue that pattern for the length of the pipe. I've never noticed any evidence of pooling or smearing. Is your input based on personal experience, or is it just another unfounded forum myth?
Re: DIY condenser/Liebig question
Posted: Sun Sep 12, 2021 10:00 am
by NormandieStill
S-Cackalacky wrote: ↑Sun Sep 12, 2021 7:32 am
Just now saw this and have no idea what you're trying to describe. I use vice grip pliers to make the crimps. I position the pliers perpendicular to the 1/2" pipe. I rotate the pipe 90 degrees for the next crimp and continue that pattern for the length of the pipe. I've never noticed any evidence of pooling or smearing. Is your input based on personal experience, or is it just another unfounded forum myth?
I can see the problem, but I guess it depends on the angle of your liebig how much of a problem it presents. If it's near vertical then you shouldn't have an issue, but if it's near horizontal then depending on the size of the crimps you could get a certain amount of pooling and smearing. Imagine exaggerating those crimps. Each would act like a weir, blocking the flow of liquid until a certain volume had built up behind it. Then the overflow would be a mix of fresh condensate and the accumulated condensate. How much of an issue this would actually be would probably depend on so many factors it'd be hard to calculate, but if you angle your tube so that none of the crimps are horizontal then it'll never be something you have to consider!
Re: DIY condenser/Liebig question
Posted: Sun Sep 12, 2021 12:07 pm
by Saltbush Bill
Glad you understand the concept so easily Normadie

Re: DIY condenser/Liebig question
Posted: Mon Oct 04, 2021 4:35 pm
by Corn Cracker
PeatyKeats wrote: ↑Sat Sep 11, 2021 12:22 pm
Corn Cracker wrote: ↑Sun Aug 29, 2021 5:11 pm
I got my design from this forum, it is ¾ over ½ hooked to a 20g pot and knocks all vapor down no problem.
The 2 tricks i picked up and used are
1. spiraling a stripped copper wire around the ½ inch to force the water to swirl around it, it does a good job, it goes into the clear discharge hose in a vortex.
2. I flattened a length of ¼ inch copper tubing and partially snipped it about every inch or so to put into the ½ inch pipe, this is supposed to break up the vapor flow and force it to the sides.
Hope this helped
1) what gauge copper wire did you use to wrap around the vapor pipe? I’ve read 16 gauge should be used, but I could only find 12 gauge nearby.
2) Have you found that putting snippets of copper in the vapor pipe helps?
I believe it was 14 or 16, i had a couple rolls of wire and just used it. I figured it would be better than none.
The copper in the vapor pipe, i have another one that i use that does not have it and have not really noticed a difference but i do use it on a smaller 5g pot so I'm not sure.
Sorry it took so long to respond
Re: DIY condenser/Liebig question
Posted: Thu Oct 07, 2021 6:20 am
by PeatyKeats
No problem. Thanks!