Determining the Point of the Heads to Hearts Cut Within the

[Lester]

I run a 2" VM column for making vodka and I don't really enjoy tasting for the absence of heads to determine when to start collecting hearts. Is there another way?

I am considering the build of a highly-sensitive DIFFERENTIAL thermometer. It will have 2 probes: one probe about 4" lower than the top of the packing and another probe about 12" below the first one. This thermometer will only display the DIFFERENCE in temperature between the first and second probe. I can resolve as small as 0.01-deg C temperature difference between the 2 probes if needed.

Once the column is stabilized I imagine the 2 probes will have exactly the same temperature since the content of the top part of the column will essentially be heads. So the differential thermometer will read 0.00-deg C.

I start to slowly draw off heads being careful not to disturb the equilibrium of the column. I imagine the thermometer described above will still show the same temperature on both probes, it will still read 0.00-deg C.

As the heads become depleted the hearts will come up next and I imagine this hearts will have a different temperature from the heads and I will be able to see a reading in the thermometer, say 0.05-deg C.

I continue to draw off heads and at some point the thermometer would read 0.00-deg C again and this would tell me that the entire column is now filled with Hearts and I can start collecting for it after a few more minutes, just to avoid smearing.

I have tried using a regular digital thermometer as an indicator for the heads/hearts cut but I saw that changes in atmospheric pressure would shift this transition point to a different reading on my thermometer. It is not reliable so I went back to tasting for heads which I really dislike.

What do you guys think of this concept?

[Prairiepiss]

I think cuts should not be made with a thermometer of any type. But that's me.

[Bob Loblaw]

Seems easier to me to just collect in small jars and identify by smell later. I am not sure why you need to know the heads/hearts cut while running. I run a VM and it works just fine to decide what jars are heads/hearts/tails after I run. Actually works better, as they've had a bit of a chance to breath and it seems more obvious what is what.

[LWTCS]

Not to mention that with just a few runs and the same procedure/recipe,
you should be able to determine a strict cut point easily.

Sounds like a fun project no matter.

[Lester]

When distilling for Vodka, a thermometer is used to accurately determine the onset of tails and this practice of using a thermometer is acceptable on this forum.

So why don't we have the same instrumentation available for the heads to hearts cut? I imagine that the thermometer's resolution is the limiting factor but today there is way around that.

Yes the multiple collection jars have been the practice since the beginning and indeed it is simple and effective. What I am trying to do is to leverage the technology available to us today to make the process more repeatable and less prone to my own mistakes in tasting.

[Prairiepiss]

I wouldn't say using a thermometer for tails cuts is an acceptaable accurate practice here?

And until they invent a thermometer that can taste. I won't recommend making cuts with one.

[Jacksonbrown]

I don't think you will get 0 diff.
The water content will increase the further down the column you go which will throw it out.
Above the packing the vapour speed will be to quick to be of use.

You would be be better off using lots of TTs to map the temp gradient. Then watch the next fraction climb the column.
I thought you were already doing this??? Does it work?

[Lester]

I don't think you will get 0 diff.

What about having only 4" distance between the 2 probes? What about having 2" distance? I need something I can measure repeatably.

You would be be better off using lots of TTs to map the temp gradient. Then watch the next fraction climb the column.
I thought you were already doing this??? Does it work?

I have only used my TTs for "seeing" if water is coming up the column, to know if I should slow down my take off rate. I have not gone as far as predicting the head/hearts cut because I don't have enough resolution on my TTs. From my observations, the transition from heads to hearts occur in less than 0.1-deg C temp change. And that temperature is not absolute since atmospheric pressure has some effect on the BPs of liquids.

What I'm really trying to determine is if the heads has a different boiling point than the hearts. From what I've read so far I think it does. So I am trying to come up with a scheme to use it for predicting the cuts. I am still unsure about this scheme so rather than drill a few more holes on my column I thought I would post the question first. Ask now drill later........

[Lester]

I wouldn't say using a thermometer for tails cuts is an acceptaable accurate practice here?

Here you go PP. For the tails cut, I didn't see anybody contradicting the procedure outlined in this thread so I took that as a well-accepted practice. But now you disagree. http://homedistiller.org/forum/viewtopi ... 63&t=15508

I have followed this tails cut procedure since I started distilling and it has worked fine for me.

[bearriver]

Are you trying to prove this works?

I can reach at or near azeo with a steady temp at the still head, and get into the tails. With my reflux rig, making the tails cut by temps would be like taking driving directions from my doberman.

[Lester]

Are you trying to prove this works?

I can reach at or near azeo with a steady temp at the still head, and get into the tails. With my reflux rig, making the tails cut by temps would be like taking driving directions from my doberman.

I am not trying to prove anything. I am trying to design an experiment before I actually build the instrument.

So how come nobody ever came forward to question the validity of the procedure outline here? viewtopic.php?f=63&t=15508
It's mandatory reading material for newcomers to this forum, as recommended by the moderators here.

BearRiver: Did you actually read it? Did you understand what you read? Have you actually tried the procedure and proved to yourself that it doesn't work? What is the resolution of the thermometer you are using? How many liters of vodka have you actually made on your rig? did you actually get in touch with kiwistiller or the moderators in this forum to tell them about the errors in that procedure? Have you seen the VLE curve and actually understand its implications?

[Prairiepiss]

Your link no worky worky?

[shadylane]

I run a 2" VM column for making vodka and I don't really enjoy tasting for the absence of heads to determine when to start collecting hearts. Is there another way??

My neighbor/kinfolk AKA Bubba, the man who is dumber than a box of rocks.
Give him the entire run, and a week later, he give back 60% that has been cut and blended.
No joke, for the heads and tales, Bubba will give the rest back. Maybe.

[Lester]

All I have done is to put forward a concept to see if it makes sense to others here. Yes it is new. Yes it has not been tried before. Yes the old tried-and-true method of multiple jars work fine. I have not questioned any of those methods.

Now if you will please try to read my proposal in a different light and come up with flaws that are not apparent to me, instead of pointing me back in the direction where we all started. Multiple collection jars yes this method works. Can we move forward now? I want to try something new.

My concept won't work according to you. Please tell me Why it won't work.

[Lester]

Your link no worky worky?

I don't know why. Here it is again
http://homedistiller.org/forum/viewtopi ... 63&t=15508

And if that still doesn't work you can follow the folders in this image to get to the actual thread.

I thought I'd make it easy for everybody so I am pasting text from that thread onto here.

Hearts / Tails Cut:
Watch the temp. You should have a digital thermometer with a 0.1*C resolution. It may rise and fall 0.1*C briefly over the course of the hearts, but when it rises 0.1 or 0.2 and stays there, it's time to pay attention. Shut the valve a bit to bring it back down. Keep the heat at the hearts level - you want to keep the vapour production and therefore reflux ratio up, so we control this with the valve, not the power. When temp rises again, shut a bit more. You're compressing tails now. It's really up to you how many times you reduce speed and keep going, but obviously you're getting less and less each time, and slower. I normally do it a couple of times and then let the last bit go to waste. I hate getting tails in my product condenser, gross and annoying to clean out, and after a long run I'm not normally concerned about that last litre.

Running a VM really is about a good thermo. Being able to read 0.1 ºC changes is what lets you make good neutral fairly easily.

[Prairiepiss]

It's not a new concept. And yes it has been tried.

But if you think it will work. Do it up.

Small jars aside.

If you are running the same recipes over and over and over again. In the same amounts. Your cuts should be just about the same amount every time. Very predictable. As LWTCS said. So if you know you get x amount of fores 6 amount of heads z amount of hearts and t amount of tails. What would be wrong with just making those same cuts every time you run it. Adjust it a little to give you a little play room. And get the best hearts cuts. And really this could be done with no tasting.

Just asking. Because I know after I run the same recipe. After about the third or fourth run. I would know where to make the cuts at.

[Lester]

Just asking. Because I know after I run the same recipe. After about the third or fourth run. I would know where to make the cuts at.

i used to think this way also. But I use a gas burner and one time I ran it a little too hot during the heads take off. The result was not nice and I had to re-distill what I thought were pure hearts. Shit happens sometimes. Just thinking of ways to cover my butt and prevent this from happening again. Yes, I should use multiple jars. I know I know.

So PP, what is wrong with this "VM Operating Instructions" thread?
http://homedistiller.org/forum/viewtopi ... 63&t=15508

Bearriver: What is wrong with that thread? Please come forward and tell the moderators about your findings.

[Prairiepiss]

Yes many call it mandatory reading. But they don't call what is written mandatory law.

The parent site is called mandatory by some. And its full of all kinds of miss information. But its historical information. That can and should be learned from. All was written by a multitude of different people. With different opinions. So as with anything. It all should be considered. But not necessarily taken as law.

If you are running a VM. And the temps start to rise. It's to late for the tails cut. That means the tails are already at the takeoff. And the tails cut should have already been made. And anything after that point. Is as kiwi said. Tails compression. Yes you are squeezing them a little more. But if the temp has risen. It still has tails in it. Compressing it a little longer. Will give you something better then just straight tails. But its not going to be great hearts. So how accurate will it actually be?

Again if you think it will work. And you want to take the time to put forth the effort to do it. By all means do it. But I bet if you look a little harder. You will find it tried by someone.

Posting while you were.

I think I would be getting rid of the gas burner. If I wanted more consistent results. Going electric with your VM. Would probably be the best mod ever for a more consistent results. Even for testing your theories that you have proposed here in this thread. For it to even have a good chance of working. The heat input will need to be repeatable. I know I wouldn't try to do this with gas heat.

[Lester]

If you are running a VM. And the temps start to rise. It's to late for the tails cut. That means the tails are already at the takeoff. And the tails cut should have already been made. And anything after that point. Is as kiwi said. Tails compression. Yes you are squeezing them a little more. But if the temp has risen. It still has tails in it. Compressing it a little longer. Will give you something better then just straight tails. But its not going to be great hearts. So how accurate will it actually be?

Thank you PP. It seems simple enough to move the thermometer a few inches down the column. Like a heads-up (tails-up?) alert.

I can't run electric because the cost is like 3x~4x as compared to gas. So I am stuck with gas ATM.

[Prairiepiss]

You would be better off with a thermometer in the normal position. And another lower in the column. That would give you more of a heads up.

This way you get a heads up. And you know what is at the takeoff point.

[NZChris]

After keeping all of your ferment variables under control, put thermometer pockets anywhere you think might be helpful and record the data from them and make logs of your comments during the runs. It shouldn't take a lot of runs to work out where the most valuable numbers are coming from. BTW, USB thermos are cheap now.

I only run pot stills. I use my records to predict when heads and tails are about to hit the spout and after a few decades of stillin those records are providing very good predictors, but I won't use them to automate til I'm damned near senile.

[Soggy Bottom Boy]

.
Lester, the solution is quite simple really.

Order an iStill from Odin, he has all of the hard stuff already figured out for you.

[Lester]

.
Lester, the solution is quite simple really.

Order an iStill from Odin, he has all of the hard stuff already figured out for you.

Thanks SBB. But where is the fun in buying ready made stuff?

If Odin has already done it then I take it that it can be actually be done.

i wish Odin would offer some helpful hints here.

[rad14701]

.
Lester, the solution is quite simple really.

Order an iStill from Odin, he has all of the hard stuff already figured out for you.

Thanks SBB. But where is the fun in buying ready made stuff?

If Odin has already done it then I take it that it can be actually be done.

i wish Odin would offer some helpful hints here.

Odin sells iStills but I'm not sure about how much of a hand he actually has in the design and programming of them...

If you don't want to buy automation then part of the joy/challenge is figuring everything out... Otherwise you're just duplicating what's already been done... Essentially, reinventing the wheel...

[Maritimer]

Hi Lester,

It's an intriguing idea. In effect, you are taking the differential dT/dx. A temperature profile is passing the sensors, generating a pulse. I wonder how this will compare to the noise, to the random minute changes in the vapour temperature.

Might as well build it and see. Some filtering might be necessary. Maybe an integrator will change to a new level. Integrate the differential signal, that is.

M

[Hound Dog]

Yea Odin give up on your patented process! That's good business.... Kidding aside, is it not just easier to taste or smell your product and know where the heads are? Like PP said, I usually run the same wash and I collect in quart jars because I know where my hearts will start and can smell tails before the temp moves. I use a LM with a thermometer that reads .1 F. A little more sensitive than .1 C. There is no temp difference between heads and hearts on mine and I despise tails so a hint of tails starts to come through just before the temp starts to climb. Yes I can cut back and reflux a bit to compact the tails some more but I usually just do this once or twice when the temp move. I just cut by smell mostly. It makes my cuts brutal but the "waste" just goes towards feints runs so it gets used anyway. I get good drink this way.

[Lester]

It shouldn't take a lot of runs to work out where the most valuable numbers are coming from. BTW, USB thermos are cheap now.

I wish I can get my hands on those USB thermometers but it is not so easy to get over here. Plotting the temps during a good run can produce a lot of valuable information. Do you have some temperature plots NZCris?

If you don't want to buy automation then part of the joy/challenge is figuring everything out... Otherwise you're just duplicating what's already been done... Essentially, reinventing the wheel...

I'm not out to invent anything Rad. Just wanting to put some degree of improvement on my still to make it easier for me to run. Lots of times it is far easier to ponder on a possible solution rather than sort through hundreds of posts in this board. (A mind-numbing activity that takes a lot of patience)

BTW going full circle with structured packing is essentially duplicating what's already been done. And yet you still found some pleasant surprises along the way.

It's an intriguing idea. In effect, you are taking the differential dT/dx. A temperature profile is passing the sensors, generating a pulse. I wonder how this will compare to the noise, to the random minute changes in the vapour temperature.

Thanks Maritimer! Yes that's the general idea but I'm not sure if I can detect any temp change right at the transition point. Maybe the temp differential is just as small as the noise? But yes an integrator can easily sort that out.

[Lester]

You would be better off with a thermometer in the normal position. And another lower in the column. That would give you more of a heads up.

Thank you PP. Now I realize that you have essentially agreed to my proposed scheme. Two thermometers near the top of the column and watch out for the change in temp, yes? What I'm proposing is to link the 2 thermometers' output together so that the temp reading will be immune to changes in atmospheric pressure. I bet Odin does the same, if not, well, that's something else to try.

[rad14701]

BTW going full circle with structured packing is essentially duplicating what's already been done. And yet you still found some pleasant surprises along the way.

Nah, I was merely proving true what to me was more than a hunch... If I hadn't been fairly certain that marbles would work better than SS scrubbers I never would have bought them to use... But, as you noticed, I didn't ask questions, I just did it... And you've probably noticed that I don't ask many questions here other than to glean enough information to help fellow members...

Nonetheless, most folks here know my stance on the whole automation subject anyway...

[NZChris]

I wish I can get my hands on those USB thermometers but it is not so easy to get over here. Plotting the temps during a good run can produce a lot of valuable information. Do you have some temperature plots NZCris?

I can't buy them here in NZ, so I bought one online. It took a couple of weeks to get here and I had to download some better software than what came with it. The still hasn't run with it yet.