Speed of stripping & speed of spirit runs

[skow69]

Yes, for single runs you want to run low and slow to avoid smearing... But not too slow... Better to run at a rate where blended cuts require no or very little dilution to aging proof of 120 - 130 proof.

You too, rad. How about running some trials and see if you can prove that?

[katzgejm]

How about running some trials and reporting your jar-by-jar results here so we can record them with the rest? Preferably with some sort of control condition for comparison. We desperately need more data. There are several examples earlier in this thread. You could duplicate one of them or modify one so it works better for you. It would be great if we could eventually accumulate enough data to analyse with some statistical confidence. Sort of crowd sourced science for the hobby distiller. I'm afraid anecdotal evidence just doesn't help.

i completely agree however i don't think i can do a similar enough side-by-side distillation to yield accurate results. my heat input especially is too difficult to control precisely. i wish i had better equipment, but that will have to come another day.

even so, it's been very clear to me over and over again that when i nudge the heat down, abv rises, and if turn the heat up, abv nosedives.

[MichiganCornhusker]

I'll be doing a big batch of whiskey soon, and I will do some experimenting and post the abv vs. heat results here.
As for whether or not more smearing occurs with faster runs, I will hang on to some of the jars and take them to TruckinButch's fest this August and see if I can get other members to chime in on that.

[rad14701]

I have plenty of wash that needs to be run... Haven't decided how it'll all get run but always keep data...

[Badmotivator]

500ml/hr is about 1/12 of my full speed (4kW no reflux) and about ¼ of the speed of the low power uninsulated pot still runs I did to investigate passive reflux. It's likely that the effect he's seeing is entirely due to his reflux ratio.

[der wo]

katzgejm,

because probably some of us (including me) wonder, that you noticed such a strong measurable effect, please write more about your still or better post a picture.

Your observation seems to be opposite to ShineRunners results, which he posted here Jan the 4th. He alternated 25% power and 50% power (of the maximum possible) and there was nothing noticeable except the normal decrease of the abv during a potstill run and of course a different flowrate.

[katzgejm]

katzgejm,

because probably some of us (including me) wonder, that you noticed such a strong measurable effect, please write more about your still or better post a picture.

Your observation seems to be opposite to ShineRunners results, which he posted here Jan the 4th. He alternated 25% power and 50% power (of the maximum possible) and there was nothing noticeable except the normal decrease of the abv during a potstill run and of course a different flowrate.

well, i'll have to do an alternating abab run and demonstrate it then. i suppose i could be mistaken, but i feel i've experienced this phenomenon many times.

[biggybigz]

20 pages later I have it figured out! Great thread!

[ShineRunner]

I'll be doing a big batch of whiskey soon, and I will do some experimenting and post the abv vs. heat results here.
As for whether or not more smearing occurs with faster runs, I will hang on to some of the jars and take them to TruckinButch's fest this August and see if I can get other members to chime in on that.

Apologies for bringing an old thread back to life, but what ever came of this MCH?

I referenced this thread in another new thread and it got me to thinking about this. Did we ever figure out speed vs taste for a spirit run? I don’t see that there are conclusions on it- just that %abv is mostly unchanged.

I’m finally about to get around to doing my experiment on clear vs steam stripped grains. I would like to do a speed vs taste experiment for my next batch, if it’s not already been settled.

SR

[Getsmokin]

From what I have done in the last few weeks and today, I believe passive reflux may have a bigger effect on flavor and smearing than power does.

[Alchemist75]

God what a debate. Was a real consensus gotten here? Should our pot stills all have tall risers? Maybe a riser with a valve controlled dephlegmator for bleeding heads off? I still think a low slow spirit run is where it's at but I could be following what is essentially a superstition.(?)

[Fuzzy]

I quick read some of this interesting thread and here's how I look at smearing. I used to do a lot of chromatography and I compare distillation to that, we are separating compounds. So if we take our spirit run which is dripped (eluted) out of our column, there are many compounds but lets simplify into 2 - alcohol & congeners. So if we run a low boil, the bell curves of these two components will be narrow and high with less overlap, better separated. In a hard boil, the bell curves will be flatter and wider with more overlap (smearing). I tried to attached a crude drawing to explain this but my format was not accepted. This is how I look at smearing comparing a high/low boil. Fast on as strip, slow on a distill run. Let me know if you think I'm off base on this. Skol!

[squigglefunk]

corn fuzed

[squigglefunk]

so it makes no difference

[NormandieStill]

so it makes no difference

I read through the whole thing I while ago and I get the impression that the correct answer is "it depends". In my fairly limited experience I get the feeling that I get more separation of flavour by running slowly. But then again, I'm getting better at making cuts and I tend to collect in more jars so it could just be that.

If I ever get the time I do still intend to test this by splitting a wash and running it twice at wildly different power levels collecting the same amount in each jar to be able to directly compare jars. But that's probably not going to happen before 2022 given my current list of projects!

[squigglefunk]

i honestly was taught to run it slow, like drip drip, maybe a little trickle now and then... took forever to do a run.

Now that I run my own still I run a steady stream, fill a quart jar every 10 mins or so. Using the same recipes I taste no difference in the product and get really similar cuts at really similar points.

[Badmotivator]

Renewed interest in an ancient thread I was deeply involved in? That’s catnip for me.

I’ll summarize what I learned: if ABV readings are a proxy measurement for “separation” (and I believe they are), then empirically the “separation” effect of running super slowly on a pot still on a spirit run is very very small, and to observe that effect will cost you hours and hours of your time. The effect is caused by the slightly higher passive reflux ratio (heat loss divided by power input.) The effect is much smaller than the effect of one true re-distillation, such as that provided by a thumper or a single plate with some active reflux.

Hope that helps!

[NZChris]

You don't have to run slow for the whole distillation to benefit from some passive reflux. You can always speed up after taking the foreshot, or after a couple of jars of obvious heads.

For spirit runs I often start slow then crank the heat up after two or three jars, then leave the dial alone to let the production rate drop until I get an obvious tails jar, then turn the heat up to strip out the last of the tails.

[LordL]

To kidnap this thread again and add in a new factor..

I have a background in chemical engineering and thermodynamics, but it's decades ago now. I can theorize, but no longer put any math to use, because of time. But here's the theory anyways:

The temperature of when a vapor condensates is depending on pressure. - True
Change in diameter of vapor path will change pressure. - Also true.

This leads me to believe we can create more reflux, not only by decreasing energy given in a passive reflux system, but also by "Playing" with pipe dimensions.

It struck me observing the still heads/ Onions typical for European stillers like Scotch (Laphroaig comes to mind: https://www.whisky.com/fileadmin/_proce ... 5b179e.jpg)

My theory is that once you have a boil, and vapour production is continuous you might be able to adjust the point of condensation by a small amount by adjusting diameters of piping, a degree or so, but that would be enough to increase reflux to some degree.

As vapour speeds increases, vapour pressure decreases.
https://www.researchgate.net/figure/Exa ... _334443943

Back in the days we calculated pressure losses for any angle, flange or valve.

Lets say we go from a 300mm boiler to a 50mm tri-clamp opening, there we would have our first loss.
If that expands to an "onion"/ Still head which is 300 mm at its widest, we build pressure again as a function of loss in vapour speed and possibility for condensation increases if we are already close to the point of condensation.
That onion will shrink down to 50 mm again to build vapour speed and take the rest of the vapours out with decrease in condensation.


Background:
Have an old labmaster and tried to make some quite heavy peated scotch from 100% peated malts from Scotland. 35-50ppm.
Result, barely any smoky notes at all.
Stripped down to 0.1% ABV on half of the stripping runs but spirit run came out clean (and took forever).
It's not an optimal setup and we are growing a bit tired of it, so my thought is to try to mimic the ideas the Scots might have found working.

Aiming for a potstill with HETP of 1-3 like the commercial pot destilleriers, while mimicing the type of bleed from the right by-products to come through.

[squigglefunk]

i honestly was taught to run it slow, like drip drip, maybe a little trickle now and then... took forever to do a run.

Now that I run my own still I run a steady stream, fill a quart jar every 10 mins or so. Using the same recipes I taste no difference in the product and get really similar cuts at really similar points.

now some time later... I am willing to eat these words, I was and am still a noob so hey

I am pretty convinced that there is a difference in taste comparatively running really slow or really fast

I think it "smears" less the slower you run it, (and any passive reflux effects might be stronger too?)

and I am not sure if I like it smeared less, I think I like it kind of in the middle? lol...

so fast stripping runs and kinda slow spirit runs but not too slow

[squigglefunk]

This leads me to believe we can create more reflux, not only by decreasing energy given in a passive reflux system, but also by "Playing" with pipe dimensions.

It struck me observing the still heads/ Onions typical for European stillers like Scotch (Laphroaig comes to mind: https://www.whisky.com/fileadmin/_proce ... 5b179e.jpg)

My theory is that once you have a boil, and vapour production is continuous you might be able to adjust the point of condensation by a small amount by adjusting diameters of piping, a degree or so, but that would be enough to increase reflux to some degree.

I agree, they do say the short squat scotch stills make a "dirtier" product (like in your pic) and the super tall long gently reducing risers make a "cleaner" one (like in the pic below)

and I think it's not just reflux, it's the expansion and compression and interaction of phase changes and what not. Heck even the angle of the lyne arm ....

how much it effects things at the hobby size scale I am not sure

[LordL]

This leads me to believe we can create more reflux, not only by decreasing energy given in a passive reflux system, but also by "Playing" with pipe dimensions.

It struck me observing the still heads/ Onions typical for European stillers like Scotch (Laphroaig comes to mind: https://www.whisky.com/fileadmin/_proce ... 5b179e.jpg)

My theory is that once you have a boil, and vapour production is continuous you might be able to adjust the point of condensation by a small amount by adjusting diameters of piping, a degree or so, but that would be enough to increase reflux to some degree.

I agree, they do say the short squat scotch stills make a "dirtier" product (like in your pic) and the super tall long gently reducing risers make a "cleaner" one (like in the pic below)

and I think it's not just reflux, it's the expansion and compression and interaction of phase changes and what not. Heck even the angle of the lyne arm ....

how much it effects things at the hobby size scale I am not sure

I think I'll just have to go all in and try. Compare and find empirical evidence. First and foremost in taste..

[LordL]

i honestly was taught to run it slow, like drip drip, maybe a little trickle now and then... took forever to do a run.

Now that I run my own still I run a steady stream, fill a quart jar every 10 mins or so. Using the same recipes I taste no difference in the product and get really similar cuts at really similar points.

now some time later... I am willing to eat these words, I was and am still a noob so hey

I am pretty convinced that there is a difference in taste comparatively running really slow or really fast

I think it "smears" less the slower you run it, (and any passive reflux effects might be stronger too?)

and I am not sure if I like it smeared less, I think I like it kind of in the middle? lol...

so fast stripping runs and kinda slow spirit runs but not too slow

Thanks for sharing! Yes, I think it's much about finding the "right" type and amount of smear. I guess that's very specific to each still. I wonder how long it took the commercial distilleries to get to where they are today. Same still, same recipe tweaking that for hundreds of years. It would be such an eye opener to get to taste a 200 year old scotch, newly made.

[Jstroke]

If we look at human behavior, my bet (not researched) is that a single distillery has probably been using the same or similar still design since it went into full scale production. They “found” an “expert”, who had a particular theory and they simply went with the experts theory or design. Once they build a customer base they would be scared to change it for fear of losing customers. They will have built a “brand” or profile that was known.

Change came about when a current “apprentice” or unhappy master distiller decided to take their theory and go find some investors they could sell the idea to that could finance the design. Slowly we have evolution. As new designs are seen and built and experimented with, designs become “proven”. But my guess is the previous or original distilleries kept their still shapes pretty similar unless they really saw the advantage in a new shape.

That is my theory.