Is this flooding or normal? (video)

[Birrofilo]

I am making my first spirit run.
I put in the still 20 litres of 40% circa sugar wash, plus 4 litres distilled water. That should be 25 litres at 32% ABV.
I use a 1m column with SPP and a glass element on top. High-purity neutral spirit is the goal.

I see liquid up to the glass element. This was wanted initially because a correct use of SPP requires flooding the packing. But now I see that even with a small power applied, the level remains high.
If I cut the power so much that I don't see the "flooding" any more, I am in doubt whether I am correctly applying enough heat for the separation to occur in the column.

I have not collected a single drop. I plan to stabilize the column for a couple hours, then "bleed" it extremely slowly.

The thermometer in the kettle indicates a stable 88°C. Doesn't seem to go up or down, actually maybe just a fraction of 1 degree up maybe in the last 10 minutes or so. The sensor in the kettle is covered with liquid (it's not in the vapours, in case that makes a difference, which I don't think it makes).

I am applying only 500W circa which seems to me a very little heat to be applied, and yet the "flooding" doesn't subside. I have almost the entire two 50cm tubes filled with SPP so maybe that is the problem, too much packing?

As you can easily see, I am as green as hope.

Any advice very much appreciated

PS I age-restricted the video for a fit of scruple, so please look at it on the main site.

Video:

[Birrofilo]

I have just lowered the power applied to the kettle to 370W. That's position "1", lower power, of the stove. I can apply less than that by using the regulator.

I say to myself that there must be a continuous vapour-liquid-vapour-liquid alternance in the column (condensation - evaporation - condensation etc.). A column flooded with liquid should not be right.

(40 minutes later) The column is now "cold" in the upper part and warm in the lower part. I suppose I should see vapours climbing up to the glass element and then being refluxed down the column, and I see nothing. The temperature in the kettle went slightly down, to 87°C. I suppose 370W is just slightly under the thermal equilibrium of the system, and nothing happens. I must see vapours, and I must feel the heat along the entire column. Therefore I just raised the power to 420W.

A few minutes later: gave a glance to a calculator and raised the power to 840W. (20:00 central European time)

[Winnipeg204]

What do you have at the bottom supporting the spp? Could it be holding it back from draining?

[StillerBoy]

Based on watching the video, you are not experiencing flooding..

If you were experiencing flooding, you would see the liquid bubbling, you are not experiencing that yet plus if the flooding was not addressed, you see the glass section filling up with liquid and pressure building from the power input would push the liquid out the top..

As to some flooding, it is your friend to get the highest purity out of the packing being used..

As to the use of power or maintaining the state of equilibruim of flooding, once the level of equilibruim is reached, back off power ever so lightly, like a quarter amp or so , base on the element size, and wait to see what happen, as it will take about five minutes to see the different.. the tick is to make very small power adjustment, either up or down in amps..

Mars

[Birrofilo]

What do you have at the bottom supporting the spp? Could it be holding it back from draining?

Good question.
I have this: https://www.stilldragon.eu/en/filter-di ... -disk.html

It's the "filter disk" which is sold as the standard for my Still Dragon column. But the case may be real that it was not designed with SPP in mind. SPP, unlike marbles or Raschig rings, sits more evenly on the bottom of the filter disk and maybe it somehow obstruct the reflux of the liquid into the pot. But then, what would I use in its stead?

[Birrofilo]

Based on watching the video, you are not experiencing flooding..

If you were experiencing flooding, you would see the liquid bubbling, you are not experiencing that yet plus if the flooding was not addressed, you see the glass section filling up with liquid and pressure building from the power input would push the liquid out the top..

I see some fast vapour coming from below, it traverses the liquid level and is certainly recondensed on top of it (the condenser immediately on top is cold). The liquid level can be maintained so that it never fills completely the glass element.

As to some flooding, it is your friend to get the highest purity out of the packing being used..

As to the use of power or maintaining the state of equilibruim of flooding, once the level of equilibruim is reached, back off power ever so lightly, like a quarter amp or so , base on the element size, and wait to see what happen, as it will take about five minutes to see the different.. the tick is to make very small power adjustment, either up or down in amps..

My main problem is understanding when and if I have reached that "state of equilibrium". If that is maintaining the liquid level stable although visible in the glass window, then I think I can do that. What I don't manage to do is to only see vapour coming through the glass (as when it is in pot still mode, without dephlegmator). What I have now is that either I have "liquid" in the window, or I have a state of slow cooling of the column. If and when I see vapour coming up, soon after the liquid rises and shows up in the window. But I can keep it stable, so if that is OK, I continue this way, a stable liquid level in the glass window.

My main problem is "mental". I don't see what I presume I am supposed to see. But maybe that's the way it works.

[kimbodious]

No, not flooding and neither is this flooding in my video

Flooding is where the level of condensate on top of the packing builds up to such an extent that it is exiting via the offtake.

[LWTCS]

What do you have at the bottom supporting the spp? Could it be holding it back from draining?

Good question.
I have this: https://www.stilldragon.eu/en/filter-di ... -disk.html

It's the "filter disk" which is sold as the standard for my Still Dragon column. But the case may be real that it was not designed with SPP in mind. SPP, unlike marbles or Raschig rings, sits more evenly on the bottom of the filter disk and maybe it somehow obstruct the reflux of the liquid into the pot. But then, what would I use in its stead?

That filter disk is not a good solution for distilling when forced reflux is involved.

[Birrofilo]

23:57 local time: I do have a problem.

After hours of liquid level at the same level (more or less) I decided I had to begin doing some "bleeding". The problem is, I could not collect anything when I turned off the cooling at the dephlegmator. Feeling the problem was actually with the packing, I nonetheless made a "last attempt" to just increase heat.

The result was a sheer "flooding" in the proper sense of the term. The final condenser became pissing alcohol at an more-than-alarming rate. I was just in time to throw a full container in the sink, and to stop all current to the still. Then I opened the window completely (while the perfume of alcohol was beginning invading the room) and for good measure I "showered" with tap water the floor and the still with my "emergency hydrant". That concludes the experiment for tonight.

Tomorrow I will disassemble the column, take the SPP away, and only use copper wire and Raschig rings. I will have to find a way to use the SPP which I have, which means finding a proper way to keep it in the column.

Any advice is as usual appreciated.

[StillerBoy]

You are running into some issue mainly cause by not understand how to use your power, plus the screen at the base used to hold the SPP, and not understanding how to balance the power with the packing and managing the dephlegmator..

In refluxing, one used full power until the base of the column is very hot to the touch or about 150*F.. at that point cut back power to about 11 - 12 amp, that depends on what size element you are using, as I am quoting power usage for a 5500w.. this allow the vapors to slowly build and move up the column.. the packing will cause resistance which is what packing at this point is suppose to do.. when the power is reduce, start you water flow to your dephlegmator with enough water flow to be able to knock down the vapors..

If at this stage you encounter flooding, then just reduce power a 1/2 amp and wait a few minutes, making sure you have enough water flow so that the condenser is cold.. reaction time is very slow, so just give it time.. once you have balance the amount of power so that you have some flooding to just about 1" above the base in the slight glass, which would where you want it to be or to be held during the run.. then allow the refluxing to go on for about 20 -30 min.. once that has happen, slow start reducing water flow to the deph. a little at a time until you can have one drop per second.. and go from there.. exact the fores at about a second for 100ml, then the heads at about 2 drops per sec. or 100ml per 10 min.. and so on..

Taking and making notes of these setting and time it take for the reaction to happen is very important in develop understanding of operating the unit in the future..

You may want to built something like I have to hold my SPP in the 3" column.. I've attached a picture to get you an idea how to put it together.. and I use a lightly compress ss scrubby to hold back the SPP.. and small one at the top so that the SPP don't get pushed out of the column, as they will..

Mars

SPP packing in a 3" column

Wagonwheel 10 ga wire

[bluedog]

Like others have said, the problem is probably the plate at the bottom. The holes are too small for the condensed liquid to drop back into the still. With the heat high enough for the still to function, lighter alchohols are being pushed up into the column (and potentialy flooding out the parrot in a very dangerous way, as you found) without allowing the heavier fractions to condense back into the pot. You could just drill some big holes in it.

[tomgndallas]

+++ on what Mars just said. I switch my still between pot and reflux, so it runs differently, but my initial approach is always the same. Heat up, check, start cooling, check, then dial back heat to start balancing, first check point at 145 to 150 for meoh, then press forward slowly.
I have to admit I found your story quite entertaining. Whilst at the same time I was wishing I was there with you to coach a bit. You obviously have a safety mind which is great. You shut down quickly when you feel danger or operations not following what you feel they should. Very good.
I have full trust and believe you will find your way with the guidance of the eons of experience here.
Stay safe.

[kimbodious]

This is a great thread! Reinforces my belief that when you ask a question in the right way that support will come that is considered and generous - restoring my faith somewhat in our community of distillers

[Birrofilo]

@StillerBoy
Yes I think I got your logic and that is what I wanted to do. But the liquid remaining high (or disappearing under the window, but with no vapour appearing on the glass) got me quite confused. The maximum power which I can apply is 2000W theoretical, but more practically 1800W because of the low-quality tension I get (nominal 230V, actual 200V or so especially during peak hours) but this power is enough for a decently fast stripping run.

I will make a new attempt today night or tomorrow. I was hesitant in putting the scrubbers under the SPP because, for some irrational reason, I did not want the SPP to get stuck inside the scrubbers. That's probably an unmotivated concern.

I should either enlarge the holes in the screen, like @bluedog suggests, or put some Raschig rings, or scrubbers, between screen and SPP. Or actually do both things. I will certainly enlarge the holes, and pretty much, and use some other packing under the SPP.

Thanks to everybody for the help, I hope this thread will also help somebody else in the future.

[Birrofilo]

Couldn't wait until tonight or tomorrow!
I unmounted and remounted the entire contraption. No screen, the copper scrubbers hold the SPP in place, or so I hope.
There is a clear reflux going on now since fifteen minutes. The temperature in the kettle is 88°C, 12 minutes ago I lowered to power to 1200W circa and the reflux is continuing in a regular way. I plan to hold it this way for 2 hours.

I think I will collect with the following strategy: fill jar 1 for 100ml, stabilize for X minutes (where X could be, e.g., 20). Then fill jar 2 for 100ml, stabilize for X minutes, etc.

I don't know whether this will give me better separation, but it is presumably easier to do, because with this strategy the dephlegmator is either 100% on (100% reflux) or is off (no cold water applied), so I will have no problem with the "fine tuning" of the cooling water.

I see that the power applied to the kettle varies. It simply it is not possible to keep it constant, that's not my fault, but the electricity utility's. I suppose in this condition it is hard to keep a constant and very low collection rate.

[StillerBoy]

I should either enlarge the holes in the screen, like @bluedog suggests, or put some Raschig rings, or scrubbers, between screen and SPP. Or actually do both things. I will certainly enlarge the holes, and pretty much, and use some other packing under the SPP.

The screen is a large part of the problem you are encountering with not being able to manage the refluxing properly.. remove it completely, not required.. build something like I did in the picture, that is the only solution to raise the efficient of your setuup..

Some SPP do get trapped in the scrubby but is not enough to be of a concern.. just be mindful went unpacking the column, doing so over cloth went removing the scrubby, then none are lost.. I do not recomment raschig rings..

Once the issue with the screen is resolved, you should be able to almost use your total power available.. I reflux with my 2" at 2100w on a 5500w element.. I start full power until about 150&F, then reduce to about 1700w (for me that's 12) and let the vapor built up, once the vapors break through, (known by the temp probe at the top), I give it about 10 min and raise my power up a touch like 1/2 amp and let it settle some then give it time to reflux.. running a reflux column on the edge is done by using 1/4 amp at a time, and giving time to adjust as it will take a few min to see the change.. large power moves will throw the refluxing equilibrium off which in large is what you were doing plus not giving it the time to adjust..

Let us know how it goes for you.. learning to dial a unit in is, managing power, water flow to condenser and take off rate is the key to stilling.. or what I relate to as " vapor management behavior".. once you develop an understand of how that works, one can operate any still and do what you from it..

Mars

[Birrofilo]

OK, I have a situation which is pretty stable now.
The power applied is 1220W (230V nominal) and it oscillates but, at the moment, the swings are not substantial, it goes from 1200 to 1230.
The temperature in the kettle is stable at 88°C and I suppose it must remain so until I begin bleeding some product.
The "window" shows a nice continuous reflow of liquid into the column. Is this a ridiculously little reflow, or is it OK?

In this situation, is there any advantage, and if so which advantage, in raising the power? I could arrive only to around 1850W if I am "lucky". Would I go "faster"? I would not be able to adjust the power very gradually, and, as Mars points out, I would risk to disturb the equilibrium in the column.

If this level of reflux is decent, I think I would keep everything as it is now.

PS The noise of water in the video comes from the sink, it's the water being pumped into the dephlegmator and being thrown into the sink. The still is very silent.

[StillerBoy]

I think I will collect with the following strategy: fill jar 1 for 100ml, stabilize for X minutes (where X could be, e.g., 20). Then fill jar 2 for 100ml, stabilize for X minutes, etc.

I don't know whether this will give me better separation, but it is presumably easier to do, because with this strategy the dephlegmator is either 100% on (100% reflux) or is off (no cold water applied), so I will have no problem with the "fine tuning" of the cooling water.

Why ? ? Where did this management method come from ? ? managing it in the manner described resolves in lost equilibrium, therefore lost of purity..

How are you setup for water supply to the unit ? ?

Do you have seperate water lines to your condenser, one to the product condenser and one to the dephlegmator.. do you have water flow controls on each line, such a needle valve on the inlet side..

Water flow control ability is as important in refluxing and the ability to manage power..

On the video, yes you do have some refluxing happening, but you are to low in power usage.. increase power until you start seeing the liquid staying at the bottom of the slight glass, then manage power at that point..

Mars

[Birrofilo]

Hallo Mars,
in fact, I thought I would have had problems in establishing a constant flow of collection. Instead, I see it's easy. I am now collecting some 100ml every 15 minutes or so. I change jar every 100ml (just to practice in spotting differences, later) and so far all is going very smoothly. There is a constant dripping of around 4 drops per second on the collection vase, which I hope is slow enough for a 2" column, and I don't stop re-equilibrating the column.

I have only one pump with a T, and two cold water lines going to the dephlegmator and the final condenser, but each cold water connection has a needle valve and I can control the two independently.

Today I jumped the "flood the packing" phase, but I did wet the packing by throwing some 300ml of liquid on the packing, from the top, after having put it in the column.

[StillerBoy]

Birrofilo..

Good to know you have separate water line and needle valve control.. this very important in having a proper setup..

You have a CM unit with dephlegmator, which once you get the understanding of how to dial the unit, is a very versatile unit.. much better than a CM with just a cooling jacket..

The take off rate in managed by managing the water flow to the dephlegmator.. strong water flow no distillate allowed to come out the spout.. reducing the flow allows some distillate to the spout..

Now the concept of running the CM is managing power with the water flow rate or balancing the two.. apply power to the flooding stage, as outline previously, once the flooding occurs, manage the power to maintain the flooding level..

Once you have that established, maintain that equilibrium for about 20 - 30 min, then reduce the water flow ever so slightly until a drop per second is achieved, then remove 100ml of fores.. once the fores are extracted, decrease the water flow a little more until you have about 2 - 4 drops per second or 100ml per 10 min doing this until you can not smell the heads.. once the heads have been extracted, reduce the water some more until you have a distillate take off rate of about 400 - 500ml per 15 min or so as now you are into the body section..

I do not know if you have a temp probe at the top of column or not.. but if one is, maintain the temp that was during the head section extract in the body section.. if the temp climb reduce the take off rate (allow more water to flow) or / and add a little more power, like 200 - 250w increase, but it's important to maintain a stable temp at the top.. as the alcohol evaporation occurs, the top temp will start to raise, that is the indicator that you are entering the tails section.. but the top temp need to be maintain at the same temp, so you do that by reducing take off rate (adding more water flow).. for a few jar then go into stripping mode for the balance of the alcohol left in boiler..

Enjoy the journey

Mars

[CopperFiend]

Aside from what has already been said, that amount of dripping from the sight glass is an unacceptable loss. It needs tightening much further or cleaning so there isnt anything on the seals

[Rrmuf]

What do you have at the bottom supporting the spp? Could it be holding it back from draining?

+1

See my question on (very similar problem) and I did determine that, in my case, it was definitely caused by the "filter disk" at the bottom of my packing.

https://homedistiller.org/forum/viewtop ... 15&t=80883

Decide for yourself if you think my issue applies to your case.
Good luck!

[Birrofilo]

I am now collecting somehow into the fourth litre, i.e. I am over half collection (I have 25 litres at 32% which means around 8 litres of total alcohol, of which I presume I will collect around 7 litres). It's the 30th jar with 100ml each, more or less. Collection begun more than 9 hours ago. The only modification which I did was a couple of hours ago, I slightly decreased the cold water to the dephlegmator because the production had considerably slowed down. I continue to collect into little jars because when I taste a drop it "pricks" my tongue and in my inexperience I presumed that the core of the collection should have no "pricking" at all. But I am probably wrong, the product comes at a very high alcohol content, and probably at 95% ABV or so there must be some pricking.

The temperature at the elbow above the dephlegmator is boringly stuck at 74,2°C with very little variations, the hot water of the dephlegmator is at 53,5°C again with little variations. The kettle though is now at 94°C. I suppose this is due to the water which refluxed back into the kettle.

@CopperFiend
The leak on the window doesn't happen with vapours, I also checked with a mirror. It only happened when the windows was filled with liquid beyond a certain level. When the level of the liquid suddenly raised, the leak became much faster. I suppose the liquid applied a pressure on the point where there is a leakage.

I opened the window element when it was new, because I had to wrap the silicon gaskets in TPFE tape. I could have done a better job, probably, but for the moment I feel I have no losses from there.

I think I will go on until 2 or 3 o' clock and then turn it all off. Tomorrow I will restabilize the column again and then begin collecting again.

I am afraid that there is something wrong with my column: maybe the collection is now too fast for good purity, or maybe there is some preferential path. It is also not perfectly vertical, but there is not much I can do about that. In the fourth liter I was expecting to collect something totally deprived of aromas. I tasted a little bit and I had a taste sensation like rum (buttery, butterscotch), very slight but present.

[StillerBoy]

Birrofilo..

Stop what you are doing and re-read the posted info I posted..

I've outline exactly how your unit should operated.. but for some reason, you are not following the instruction.. thereby causing yourself all the issue you describing..

A 25L run of 32% should be done under 4 hrs total from start to finish with the unit you have.. so re-read my post..


Mars

[Birrofilo]

Mars,
thanks for your help but there is something which I am missing due to my inexperience:

1) Do I understand you well that I should flood the column first, and then keep it flooded until the base of the "window"? For what I read so far, this is not the way SPP should operate (or reflux in general); If the liquid is kept in liquid form, how can the fractions separate? It's the evaporation-condensation-evaporation-condensation which actually separates the fractions, in my understanding. If I keep the column flooded, I only have 1 plate working (only 1 surface of evaporation-condensation).

2) "once the fores are extracted, decrease the water flow a little more until you have about 2 - 4 drops per second or 100ml per 10 min doing this until you can not smell the heads" My problem here is that I don't know when the heads are over. To me it's always the same smell (if we except maybe the first 100-200, or maybe 400 ml, when I felt some "medicinal" Hospital stink). Even after 2 litres, or after 3 litres, it's the same as after 1 litre, or after 600 ml. I always feel this "butter", "rum" feeling (yes, Rum gives me that idea) and I always feel the pricking in the tongue, in the cheeks, even after dilution. I feel neutral should be more flavourless, and much more "silky" in the mouth. That was my goal. That's why I did not raise the collection rate, and I went on filling small jars: because I never had the sensation that I had arrived to the "heart".

3) "I do not know if you have a temp probe at the top of column or not.. but if one is, maintain the temp that was during the head section extract in the body section.. if the temp climb reduce the take off rate (allow more water to flow) or / and add a little more power, like 200 - 250w increase, but it's important to maintain a stable temp at the top.. as the alcohol evaporation occurs, the top temp will start to raise, that is the indicator that you are entering the tails section.. but the top temp need to be maintain at the same temp, so you do that by reducing take off rate (adding more water flow).. for a few jar then go into stripping mode for the balance of the alcohol left in boiler.."

You see, I have the thermometer on top of the dephlegmator, at the beginning of the elbow. This gives me a temperature which I kept stable at let's say 74°C (it was mostly stable by itself, I did not need to manoeuvre). Yesterday night, at around 4 a.m., when I was collecting my 4th or 5th liter (out of total theretical 8 ) - i.e. when I was supposed to be in the middle of the middle - the temperature to the top begun raising and it arrived fast beyond 77°C. Keeping your advice in mind and following it, because my goal is an odourless neutral, I increased the water flow reducing the temperature of the dephlegmator, bringing it back to 74°C: the discarded hot water went from 51°C to 31°C. Naturally, the production rate slowed again. If I want to increase the collection rate, I must let the temperature raise at the elbow. That, as you say, might bring some tail fractions inside the collected product. But then, if I go on with that stable 74°C temperature at the top, I will need forever before I extract a decent amount of the potential alcohol.

As a side note, before going to bed I measured the alcohol content, and it was 93% (at 20°C). Considering that I have something like 80 cm of height of SPP, corresponding, in pure theoretical theory, to 40 plates, plus the copper scrubbers on the bottom, I suppose I should get azeotropic mix and not 93%. I suspect there is something wrong in my column: specifically, I suspect the fact that it is not perfectly vertical converts it to a 3 or 4 theoretical plate system. Is that possible?

[StillerBoy]

2) "once the fores are extracted, decrease the water flow a little more until you have about 2 - 4 drops per second or 100ml per 10 min doing this until you can not smell the heads" My problem here is that I don't know when the heads are over. To me it's always the same smell (if we except maybe the first 100-200, or maybe 400 ml, when I felt some "medicinal" Hospital stink). Even after 2 litres, or after 3 litres, it's the same as after 1 litre, or after 600 ml. I always feel this "butter", "rum" feeling (yes, Rum gives me that idea) and I always feel the pricking in the tongue, in the cheeks, even after dilution. I feel neutral should be more flavourless, and much more "silky" in the mouth. That was my goal. That's why I did not raise the collection rate, and I went on filling small jars: because I never had the sensation that I had arrived to the "heart".

Birrofilo.. circa sugar is raw cane sugar.. raw cane sugar is use to make rum with.. that explain this issue, you have made rum.. rum refluxed even at 95% still has a strong flavor..

For a spirit with no flavor requires to use plain white sugar.. stripped and refluxed twice.. and only then will you have an almost flavor less spirit.. refluxed only once will not do it and that with plain white sugar.. if your using raw sugar it will make rum, white sugar will make a neutral, and an AG will make a vodka, it is very hard to totally remove the flavor with the unit we have..

Will address some of the other issues as I get time..

Mars

[Birrofilo]

Mars,
yes, I used common table sugar, white sugar. I made 4 "birdwatcher's": each lot was 20 litres distilled water, 200g tomato paste, the juice of half a lemon, and common baker's yeast of the fresh, soft kind. I said "circa" as in "more or less". Those 4 lots were stripped to 5 litres at 40%, and my spirit run was the four strips + 5 litres distilled water (25 litres at 32%).

But, in making the stripping runs, I added a nut of butter (more or less the same quantity as the yeast) to the liquid, as an anti-foam agent. The aromas of butter, tomato, and yeast should have gone by now.

Maybe what I perceive as "butter" is simply the way I perceive the taste of ethanol. I have never tasted 95% product produced by other people. But I did taste some distilled product (such as brandy, or fruit brandy) which was very "smooth" even at 40%, I desume from that that I might have some congeners in my product because I perceive a "bite" even when I dilute my product three times (1 part alcohol 2 parts water). I assume that congeners "bite" whereas pure ethanol doesn't. That might be a wrong assumption. Maybe what I tasted when confronted with a smooth spirit was not only aging, but also glycerine! Maybe ethanol is not smooth.

But the fact that I obtain a 93% with all that packing reinforces in me the idea that I have some operating problems and that i am taking in some congeners as well, hence the "bite" and the "butter". Also, I don't want to say it is unpleasant: it is generally good palatable stuff, but it is not what I thought I would have obtained and should have obtained.

[StillerBoy]

I used common table sugar, white sugar. I made 4 "birdwatcher's": each lot was 20 litres distilled water, 200g tomato paste, the juice of half a lemon, and common baker's yeast of the fresh, soft kind.

Why are you using distilled water, as it's the worst water to used to make a ferment with.. and no other ingredients other than the tomato paste and lemon juice, many ingredient that the yeast require were missing.. I'll assume it took a good while to ferment out (more than 5 - 6 days), and it didn't clear will.. and that where you issue with flavor being carry over..

But, in making the stripping runs, I added a nut of butter (more or less the same quantity as the yeast) to the liquid, as an anti-foam agent. The aromas of butter, tomato, and yeast should have gone by now.

In the stripping run, again I'm assuming, because it didn't ferment properly, and therefore didn't clear well, all the fine sediments still in the wash, cause the wash to foam and alter the flavor of the low wine..

The process to a good neutral spirit starts with making a wash that is healthy for the yeast.. your wash wasn't from that point.. the recipe in the T & T section were put together many yrs back and have really never been update so as to finish properly and clear well.. the water using makes a big different, not from a point of local area, but from a point of across the world as each area requires some adjustment..

I assume that congeners "bite" whereas pure ethanol doesn't. That might be a wrong assumption. Maybe what I tasted when confronted with a smooth spirit was not only aging, but also glycerine! Maybe ethanol is not smooth.

A good neutral start with a well made plain sugar wash, such as Shady's or Wineo's if you want a better neutral that what the Birdwatcher will.. the "bite" you describe is from an improper made wash.. no amount of distilling with remove all of the bite, especially from a BW, as a still is only an alcohol / water separator it will not improve a improperly made wash.. you don't state the amount of sugar used per batch, but I'll assume from the amount stripped by it was not much.. if correct, sugar wash batch which result in less than 10% abv, it will have a stronger bite than one of 10%..

The other major issue is that you do not have enough understand of how to operate the unit you have yet.. on one's own, learning to operate a unit, with a start point of very little understand of vapor management behavior, it will take many session to even get an entree level result.. you are starting out and achieved a 93% which corrected will a little lower, but to get 92% to 95.5%, is not as easy as it is stated to be.. you may have all the tools to make it happen, but the big thing is learning to manage those to make it happen.. and that will take time, especially being by yourself and learning from a distant..

Don't give up just yet.. slow down some, let what has been said and what has been experience, sink in some.. many time wanting to go to fast only cause more issue than required..

Mars

[Birrofilo]

Yes, I actually used tap water. For the first wash I used 5 L of distilled water because I needed the container, so that remained in my mind. I wouldn't waste money and muscular force for that. So, out of 80 litres in the four batches, I used 75 litres tap water. In the first batch it was 5 L distilled water and 15 litre tap water. In the other batches it was 20 litres tap water. I have no idea why it remained in my mind that I used distilled water, other than I actually use the distilled water flask to fill the fermenter (very practical, transparent and with a handle).

I used 4 kg of white sugar in each batch. That should have given me a 10% ABV liquid to work with.

I always cleared the liquids with PVPP after fermentation and the liquid ending up in the kettle was, if not transparent (certainly due to the tomato) certainly not worryingly cloudy. Actually it appeared perfectly transparent in the "crystal tube", one would see a colour only in the kettle.

I don't think the initial wash had any problem. Maybe the butter was the problem. Actually in the last batch I used some frying oil. Maybe too much butter, or maybe butter is not a good idea when making neutral. If I remember well, I felt this "butter" aroma in the low wines, so I decided to use frying oil for the last batch. The butter thing was there after the stripping runs. Or, again, maybe it's just the way I detect ethanol.

Generally speaking, even if my fermentations had come out "dirty", with many congeners, I assume the congeners would be much reduced in the hart of the production: if my still and myself were working correctly, I would have extracted a larger amount of stinky heads, but the nature of the reflux distiller should guarantee that, provided a good stabilization and all is well operated, the core of the collection would be clean. I still think I have a problem with the way I operate the still.

[Birrofilo]

In general, seeing my conduct, I see that I fell into the most classical beginner mistake: watching the temperature.
I was afraid to bring inside the "tails" when the temperature at the elbow suddenly rises, but I was very far from that moment. I see from my notes that heads are generally around 83-85 °C, and the heart is up to around 90°C. Tails have a vapour temperature of around 93-95 °C. I should not worry about collecting tails temperature until my vapour is up to 90°C. I begun worrying too easily and too fast. The theory is firm, but the practice is weak.