When to use a thermometer with a pot still.

Simple pot still distillation and construction with or without a thumper.

Moderator: Site Moderator

Post Reply
User avatar
piperdave
Site Donor
Site Donor
Posts: 348
Joined: Wed Feb 18, 2015 6:29 am
Location: Great White North

When to use a thermometer with a pot still.

Post by piperdave »

I use two thermometers with my pot still when I am doing a stripping run. I have a SS scrubbie in my riser so I can definitely see when the vapor hits my liebig. The temp. at the top of my riser stays ambient until the boiler temp. hits 85 C (~10% ABV rum wash), the vapor breaks thru the scrubbie, the riser thermo. starts to jump and I cut the power to stop the puking. That's how I use a thermometer with a pot still.
stripping run 2 thermometers
stripping run 2 thermometers
If you can't be a good example, at least be a terrible warning
RedwoodHillBilly

Re: When to use a thermometer with a pot still.

Post by RedwoodHillBilly »

piperdave wrote:I use two thermometers with my pot still when I am doing a stripping run. I have a SS scrubbie in my riser so I can definitely see when the vapor hits my liebig. The temp. at the top of my riser stays ambient until the boiler temp. hits 85 C (~10% ABV rum wash), the vapor breaks thru the scrubbie, the riser thermo. starts to jump and I cut the power to stop the puking. That's how I use a thermometer with a pot still.
pot_still.jpg
What ever works for you, that's what counts. I use the thermo at the top for 2 reasons, 1) to tell me when to turn on the PC water. 2) as a analog for a parrot i.e. what %abv I'm collecting.

To each their own, A thermo isn't needed, but I feel that it gives me more info.
User avatar
piperdave
Site Donor
Site Donor
Posts: 348
Joined: Wed Feb 18, 2015 6:29 am
Location: Great White North

Re: When to use a thermometer with a pot still.

Post by piperdave »

Exactly. That's how I use them for strips. The more informed you are the better. I can tell by feel and sound when it's gonna tip but I like to the additional info. I'm just adding to the lexicon of info here. It might help someone.
coming along.
coming along.
If you can't be a good example, at least be a terrible warning
yakattack
Site Donor
Site Donor
Posts: 1755
Joined: Sun Nov 16, 2014 5:37 am

Re: When to use a thermometer with a pot still.

Post by yakattack »

Just a tip ditch the carboy handle. It's a good way to lose a carboy full of low wines. Get a milk crate for moving the carboy. Trust me, learned the lesson the hard way.

Yak
HDNB wrote: The trick here is to learn what leads to a stalled mash....and quit doing that.
RedwoodHillBilly

Re: When to use a thermometer with a pot still.

Post by RedwoodHillBilly »

yakattack wrote:Just a tip ditch the carboy handle. It's a good way to lose a carboy full of low wines. Get a milk crate for moving the carboy. Trust me, learned the lesson the hard way.

Yak
Ouch... I still have 3 5gal carboys that I bought 35 yrs ago, No crate or handle, but I always have dry hands when moving them. I still have the same vintage hydrometers (beer and P&T). Haven't broken any of them yet.

Now that I said that, I'll probably break all of them today. :(
User avatar
Desvio
Site Donor
Site Donor
Posts: 296
Joined: Sun Feb 15, 2015 10:35 pm
Location: Pacific Northwest

Re: When to use a thermometer with a pot still.

Post by Desvio »

RedwoodHillBilly wrote:
yakattack wrote:Just a tip ditch the carboy handle. It's a good way to lose a carboy full of low wines. Get a milk crate for moving the carboy. Trust me, learned the lesson the hard way.

Yak
Ouch... I still have 3 5gal carboys that I bought 35 yrs ago, No crate or handle, but I always have dry hands when moving them. I still have the same vintage hydrometers (beer and P&T). Haven't broken any of them yet.

Now that I said that, I'll probably break all of them today. :(
+1, the handles are scary

That said I lift everything by hand, but have a cart for moving them. Same goes for my thermometer, honestly I quit reading it most of the time and just run my hand down the column for an idea of where I am at starting up.
People say that I'm a bad influence. I say the world's already f#cked -- I'm just adding to it.
User avatar
still_stirrin
Master of Distillation
Posts: 10337
Joined: Tue Mar 18, 2014 7:01 am
Location: where the buffalo roam, and the deer & antelope play

Re: When to use a thermometer with a pot still.

Post by still_stirrin »

Desvio wrote:...honestly...just run my hand down the column for an idea of where I am at starting up.
+1.

After you've run your still a while, you know the signs...repeatability and process control make it very predictable.
ss
My LM/VM & Potstill: My build thread
My Cadco hotplate modification thread: Hotplate Build
My stock pot gin still: stock pot potstill
My 5-grain Bourbon recipe: Special K
joeymac
Swill Maker
Posts: 306
Joined: Sat Oct 17, 2015 6:22 pm

Re: When to use a thermometer with a pot still.

Post by joeymac »

I only use my thermometer to let me know
a) When to turn on the water
b) When to stop stripping out the tails

Stripping run I collect everything until the vapor temp reads 99.1 degrees C, give or take a couple tenths depending on how much I got collected.
On a spirit run, I collect slowly in jars until I'm well past the hearts (smell/taste) and then crank the heat and strip out into a big jug until 99.1 degrees C.

yeah, I could probably run without it pretty easy. But why? It makes things easy and almost thoughtless.
Hint: Using a digital thermometer with a programmable alarm set point makes this even more idiot proof.
Last edited by joeymac on Fri Apr 14, 2017 2:46 pm, edited 1 time in total.
"Woe to those who are heroes at drinking wine and champions at mixing drinks" - God (Isaiah 5:22)
So evidently, God wants us to drink our whiskeys single barrel and our Bourbons neat.
RedwoodHillBilly

Re: When to use a thermometer with a pot still.

Post by RedwoodHillBilly »

joeymac wrote:I only use my thermometer to let me know
a) When to turn on the water
b) When to stop stripping out the tails

Stripping run I collect everything until the vapor temp reads 99.1 degrees C, give or take a couple tenths depending on how much I got collected.
On a spirit run, I collect slowly in jars until I'm well past the (smell/taste) and then crank the heat and strip out into a big jug until 99.1 degrees C.

yeah, I could probably run without it pretty easy. But why... it makes things easy and almost thoughtless.
Hint: Using a digital thermometer with a programmable alarm set point makes this even more idiot proof.
a) yup, me too

b) about 11%abv or so, sounds about right.
User avatar
piperdave
Site Donor
Site Donor
Posts: 348
Joined: Wed Feb 18, 2015 6:29 am
Location: Great White North

Re: When to use a thermometer with a pot still.

Post by piperdave »

Wet hands and lifting a carboy with 12 liters of low wines made me get the handles but if thats a bad idea ( never had an issue with a handle yet) I may switch to the milk crate idea. I just use my thermo's for stripping. I pretty much know when things happen with the three or four recipes I use, very repeatable, and with spirit runs it's all taste and smell. I strip to 97 C. Leaving a little in the pot but the distillate pretty much tastes like water so good enough.
If you can't be a good example, at least be a terrible warning
User avatar
NZChris
Master of Distillation
Posts: 13062
Joined: Tue Apr 23, 2013 2:42 am
Location: New Zealand

Re: When to use a thermometer with a pot still.

Post by NZChris »

My top temperature has always had an unreliable relationship with abv at the spout, so that thermowell is usually empty. It could be used to automatically shut off the heat before a puke, but I don't run it often enough to warrant it and a bit of puke doesn't hurt the products that tend to puke.

My Leibig has a controller, so that looks after itself. I don't even need to turn it off when I'm finished.
User avatar
30-06
Novice
Posts: 19
Joined: Fri Jun 27, 2014 9:01 am
Location: off yonder

Re: When to use a thermometer with a pot still.

Post by 30-06 »

There's a distillery near my home. Instead of a thermometer, they do it the old timey way on their big old burly still. On the pipe between the boiler and condenser they have a tin can hung by a string, and the string affixed to the pipe by wax. Pipe heats, wax melts, can falls, time to hit the water and start collecting.
yakattack
Site Donor
Site Donor
Posts: 1755
Joined: Sun Nov 16, 2014 5:37 am

Re: When to use a thermometer with a pot still.

Post by yakattack »

NZChris wrote:
My Leibig has a controller, so that looks after itself. I don't even need to turn it off when I'm finished.

Can we talk about this please? Can you explain the system. Pictures? Details? Please?

Yak
HDNB wrote: The trick here is to learn what leads to a stalled mash....and quit doing that.
RedwoodHillBilly

Re: When to use a thermometer with a pot still.

Post by RedwoodHillBilly »

NZChris wrote:My top temperature has always had an unreliable relationship with abv at the spout, so that thermowell is usually empty. It could be used to automatically shut off the heat before a puke, but I don't run it often enough to warrant it and a bit of puke doesn't hurt the products that tend to puke.

My Leibig has a controller, so that looks after itself. I don't even need to turn it off when I'm finished.
Are you saying that your thermometer is in a thermowell? I have found that that can give a false/slow reading. My thermo is SS and right in the vapor path. If you use a thermowell, do you at least use a thermo conductive grease? If so, you will see a thermo lag.
User avatar
NZChris
Master of Distillation
Posts: 13062
Joined: Tue Apr 23, 2013 2:42 am
Location: New Zealand

Re: When to use a thermometer with a pot still.

Post by NZChris »

RedwoodHillBilly wrote:
NZChris wrote:My top temperature has always had an unreliable relationship with abv at the spout, so that thermowell is usually empty. It could be used to automatically shut off the heat before a puke, but I don't run it often enough to warrant it and a bit of puke doesn't hurt the products that tend to puke.

My Leibig has a controller, so that looks after itself. I don't even need to turn it off when I'm finished.
Are you saying that your thermometer is in a thermowell? I have found that that can give a false/slow reading. My thermo is SS and right in the vapor path. If you use a thermowell, do you at least use a thermo conductive grease? If so, you will see a thermo lag.
The original thermometer I had in direct contact with the vapor now resides in a drawer of stuff I keep because I might find another use for it one day. It has been replaced by a thermowell I found in the same drawer of stuff.
User avatar
piperdave
Site Donor
Site Donor
Posts: 348
Joined: Wed Feb 18, 2015 6:29 am
Location: Great White North

Re: When to use a thermometer with a pot still.

Post by piperdave »

Controller on the liebig....I would be interested in that as well.
If you can't be a good example, at least be a terrible warning
User avatar
NZChris
Master of Distillation
Posts: 13062
Joined: Tue Apr 23, 2013 2:42 am
Location: New Zealand

Re: When to use a thermometer with a pot still.

Post by NZChris »

piperdave wrote:Controller on the liebig....I would be interested in that as well.
Simple Leibig temperature controller.
20 PSI pressure reducer to a water solenoid valve feeding a reservoir, (surface area more important than volume), gravity fed to the Leibig.
Thermocouple at the spout to a cheap controller, (my controller is so cheap that it has no readout and is 'set and forget' using DIP switches).
Thermometer independant of the controller to monitor the condensate temperature.

Set the water flow at the supply to the maximum you think you will need for the run.
Set the controller to whatever temperature you are happy with.
User avatar
thecroweater
retired
Posts: 6079
Joined: Wed Mar 14, 2012 9:04 am
Location: Central Highlands Vic. Australia

Re: When to use a thermometer with a pot still.

Post by thecroweater »

Very similar to my first pot still, I did have a sealed thermo well in the top . I did give me information like when to turn water on adjust the heat and pay closer attention. You can touch the column and get the same info but so what, thermometers are only a problem when ppl think they can run the still with them :thumbup:
Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety. Benjamin Franklin
RedwoodHillBilly

Re: When to use a thermometer with a pot still.

Post by RedwoodHillBilly »

NZChris wrote: The original thermometer I had in direct contact with the vapor now resides in a drawer of stuff I keep because I might find another use for it one day. It has been replaced by a thermowell I found in the same drawer of stuff.
To each their own. I have a 4 wire (kelvin connection) RTD at the top of my column. It gives me a quick and accurate reading, but like I said to each their own.
User avatar
piperdave
Site Donor
Site Donor
Posts: 348
Joined: Wed Feb 18, 2015 6:29 am
Location: Great White North

Re: When to use a thermometer with a pot still.

Post by piperdave »

thecroweater wrote:thermometers are only a problem when ppl think they can run the still with them :thumbup:
I agree 100%
If you can't be a good example, at least be a terrible warning
User avatar
NZChris
Master of Distillation
Posts: 13062
Joined: Tue Apr 23, 2013 2:42 am
Location: New Zealand

Re: When to use a thermometer with a pot still.

Post by NZChris »

RedwoodHillBilly wrote:
NZChris wrote: The original thermometer I had in direct contact with the vapor now resides in a drawer of stuff I keep because I might find another use for it one day. It has been replaced by a thermowell I found in the same drawer of stuff.
To each their own. I have a 4 wire (kelvin connection) RTD at the top of my column. It gives me a quick and accurate reading, but like I said to each their own.
I find I don't need to know the abv at the spout for either stripping or spirit runs. I strip into a glass container large enough to take a whole strip and an alcometer is floated in that so that I can strip to my desired abv. Spirit runs are into jars by volume, not by abv. The boiler temperature tells me the abv of the charge and that gives me a good idea of where I am in the distillation.
User avatar
bilgriss
Site Donor
Site Donor
Posts: 1690
Joined: Fri Feb 05, 2016 2:28 pm
Location: Southeast-ish.

Re: When to use a thermometer with a pot still.

Post by bilgriss »

As has been mentioned, I watch the thermometer in the vapor path to judge when I should start circulating water, and sometimes as a sanity check into tails when I'm getting ready to shut down. As long as you don't try to use it to judge how to run the still, it can be informative. But if it were to disappear, I wouldn't really lose anything.
APD
Novice
Posts: 18
Joined: Fri Jul 28, 2017 1:03 pm

Re: When to use a thermometer with a pot still.

Post by APD »

I run two thermometers - one in the head of the pot still and one in top of the thumper - as well as the parrot.

Started doing this since I began - initially just to give me an idea of what was going on while I was learning and getting my head around the process.

Later I started getting into the habit of jotting down temps relative to time and product quantity taken off, a bit retentive ... again - just helps me get my head around whats going on and makes things a bit more intuitive each time.

Was interesting to see things like how delays flowed thru the system (gust of wind disrupting the flame, or cooling the still in bad weather) still head vapor temp would drop off almost straight away, thumper temp hardly at all and the after a delay you'd see the disruption at the parrot end in the alcohol stream.

Cool also plotting the change of temp in the thumper vs alcohol abv dropping off and seeing how the two totally corresponded.
Post Reply