What determines the ideal collection speed

Steve-Broady

I’m sure there’s no simple answer, but I’m trying to understand at least a little theory here. What factors determine the ideal collection speed out of a given system? I’ve always heard that slowing down is better for a spirit run, and that’s definitely been my observation as well. But on the other hand, a 1 gallon air still and a large commercial distillery obviously can’t run at anywhere close to the same collection speeds, and yet both are capable of making good spirits if done with care.
Let’s take my still as an example. It’s an 8 gallon pot still which I run on the (electric) kitchen stove, and I collect through a homemade shotgun condenser. A 5 gallon stripping run might take 2-3 hours at with the large burner at full power, and the condenser seems to be able to handle everything that I throw at it. A 4 gallon spirit run might take 3-4 hours, using the smaller burner but still on high. The condenser is easily capable of handling that, but at full power on the large burner I have to watch it very carefully and keep the cooling water at full flow or some vapor will get by.
In other words, my setup seems to work well enough for what I’m doing, but there is no extra capacity. So what happens if I make some improvements? Let’s say that I build a better condenser (which is what got me started thinking about this question). All other things being equal, would I be able to make a spirit run at higher power while keeping the same relative quality? Or is the ideal collection speed dictated by the volume in the boiler and the ABV of the charge?
To be clear, I’m not in a hurry, though time is always valuable. I’m trying to understand, so that I can make more informed decisions in the future.

Yummyrum

When it comes to a Pot still run , I think the main thing is how big your boiler charge is .
As you have pointed out , a still the size of an Airstill or a huge 10,000 litre boiler charge that a Scotch Whisky maker might use can all make a quality spirit . One is dripping at a rediculously slow speed while the other is pissing like a mule .
Now heres the fun fact . It takes just as long for an Airstiller to do a spirit run as a master distiller in Scotland….. about a days work . So time to complete a run is the common theme
So what changes ? …….The power .
The less you have in your boiler , the less power you should run it .
The more you have in your boiler , the more power you need to get the run to finish in the same amount if time .
Run too quickly and you get smearing . I think we all agree on that . The happy speed seems to be to get the job done in about 6 hours , run harder , and you smear , run slower , and there are little gains for your extra time .
Therefore , the takeoff rate is related to boiler charge . .on a Pot still .
You will often read that takeoff rate should be about the size of a pencil lead stream . Now that has been repeated over and over , but really , its a “typical” size that a home distiller running say 8gal might use .
Run 4 gal and you should reduce to 1/2 a pencil lead stream .
Rn 16 gal , you can double that pencil lead size stream . And of coarse , this is achieved by adjusting yiur power to the boiler .
And can all further posters specify if they are talking about Pot still runs or reflux still runs so as not to cause confusion.My recommended goto . https://web.archive.org/web/20171228074 ... ory/theory
Some of it is outdated but most of the basics are correct .

NZChris

It depends on what you're making and your preferences.  I've read many posts saying to run slow when making products that I prefer to run fast.
Gin, I run for anything from one hour to six hours depending on the style of gin.
Rum, I often run fast, when most advice I've read on the forum is to run slow, but that said, I might have it idling for a long time before I let it start producing.  Whiskey, I run both fast and slow depending on what I'm making, often starting fast, (after the nail varnish has gone), then not adjusting the power until well into tails.
For each product I make, I do my homework to help decide what still configuration I would like to try and how to run it.

Demy

I agree with others. There are some general advice on the forum but my advice is to experiment with yourself to understand the differences (starting from the general advice). For example, I do not run very fast even if the column or the condenser of the product allows it, I take the necessary time, I don't like the "heavy" but aromatic and clean products.

shadylane

What determines the ideal collection speed?
That's easy to figure out.
Practice with the still you have, until you figure out its limitations.
Modify it and run it some more until you have the answer.  

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Saltbush-Bill

Your answer is right above.
One thing I can say with certainty is that the speed that you think is right when your learning , is more than likely not the speed you will run at a year later. In the end you and your friends taste buds will be what decides what speed suits you and your still.

Steve-Broady

I appreciate all the advice, as always. I meant to add that I suspected there might be some sort of magic energy/charge volume ratio, but that a lot would depend on the objective and style of spirit.
As I said, what I have now seems to work well with my current skills, but I am always wondering where I should be looking to improve, with both skill and equipment. And I like to understand theory as well as practical applications, to better guide my decisions in the future.
It would seem that the short, practical answer right now is that I don’t need a bigger condenser. What I need most is time. Which is nice, because I enjoy time spent learning. Especially if I’m rewarded with a nice drink at the end!

Oatmeal

Heh. A bigger condenser can make stripping faster...
Yummy's idea of about 6 hours for a spirit run regardless of still charge is a fun way to think about it!
Eventually if I read enough of NZChris's oblique posts, I won't actually have to go to the library, because he's letting too much slip  

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a good reminder to let my upcoming rum run cook a little bit before I start drawing it off to let some esters develop. The why's of running faster for certain products I'll leave until I can learn to manage a run like a gentleman.Warning: slightly inebriated novice!

still_stirrin

+1.
Steve, if you have to ask, “how fast”, then you need to gain more experience.  
The fact is, “there is no correct answer”.  Many factors affect production rate; as noted, boiler charge size, power supply, %ABV of the wash, and even what you’re trying to make.  And another factor is the stillhead you’re using, as some styles can run faster, or produce faster than others.
Bottomline, you just need to run it and learn the idiosynchronicity of your still and how your wash affects the production.  I’ve run my stills enough times to know how to make them most efficient, yet differences in the washes and what my target spirit is will cause operational adaptions.
We often get the “how fast” question from new hobbyists and there may be many responses that provide differing answers.  This points to the fact that “things vary” and you just need to RUN IT.  Some things you can learn by reading the website, others you just have to learn “the old fashioned way”.
Good luck, and be safe.
ssAttention new distillers: Cranky's spoon feed info
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

Ben

I think Yummy nailed it, volume, power and operator preferences. I am not sure ABV is a huge contributor, it takes about the same time for me to run a "1.5" run as it does a 1.0 (through plates). I recently dropped 3 gallons of barrel strength and 8 gallons of fresh beer into my still (pot mode), I expected it to take all day to run it... ended up taking just a little longer than a normal spirit run.  
I've often thought of cutting the bottom off my boiler and welding a second keg on to bring the volume up to about 29 gallons, hoping to be able to run more power and create more volume in a shorter time. The trouble is, I generally run 1-2 plates and just run everything once. I think the plates are the limiter of speed, not the boiler/power. But that's the time savings in the program... I can do one 11 gallon mash, from dumping mash into the still to pumping the hot backset down the sink in a little less than 4 hours. I then have product that is ready to blend and age. If I strip it adds about half to the time investment (and I have to run 3 mashes, strip, combine, spirit, which means I can't tweak the recipe as often).
I think my point is there are other ways to save time in your distilling program besides just the still. If you are doing all grain there are tons of ways to speed that up. Speeding up stripping runs, just by adding more power or by building a continuous stripper could save tons of time. Switching from a plain pot to a pot and thumper, or a plated column could get you there as well.:)

OtisT

Right or wrong, I use similar guidelines as Yummyrum when it comes to the duration of a pot stilled spirit run.  I plan on an 8 hour day, including warmup.   When fores are done being pulled I do the math then set my collection rate for about 6-7 hours to collect everything, though I stop a little early because I don’t go deep into tails.  I do this on pot still spirit runs from 2 to 12 gallons.   
OtisOtis’ Pot and Thumper, Dimroth Condenser:  Pot-n-Thumper/Dimroth
Learning to Toast:  Toasting Wood
Polishing Spirits with Fruitwood:  Fruitwood
Badmotivator’s Barrels:  Badmo Barrels

LWTCS

I think as long as you are emphasizing sensory awareness you'll find the best speed.
Reason I say that is because just because a still can run really well at faster collection speed doesn't mean you are making your best spirit at that speed.
On a  professional 200 gallon kettle charge for example some folks like to collect at 30LPH and others might prefer 35 or 40 LPH.
Extrapolate that down to our scale and it could mean the difference between 1.5 to 3 LPH or some such.
Getting enough reps under your belt will get you pointed in the right direction. But Salty is right in that your point of view will very likely evolve.Trample the injured and hurdle the dead.

BrewinBrian44

I completely agree with this. I always use taste and smell to determine my max collection rate. If there’s smearing, I slow down, if it’s too clean, I speed up. I use the same baseline power target and adjust from there after the product starts flowing.
Funny thing, I’ve also experienced that spirit runs seem to take the same about of time, regardless of still charge. I distilled 5 gallons of failed 5% ABV homebrew and had to run very slow to keep it from smearing. Like 1 drip per second. Ended up taking 6 hours.
These days, I usually anticipate 8 hrs from power on to dumping backset

NZChris

You will get better answers if you ask more specific questions, this question casts a too wide a net.
When I'm looking for a method to use, it is for a very specific product so that I'm not incorporating techniques best used for something else.  When researching, I start with the end product and work my way back through each stage of production, noting what equipment is optimal, what abv to aim for and how to run it, how to optimize the ferment and finishing with the ingredients needed.

The-Baker

I've often thought of cutting the bottom off my boiler and welding a second keg on...
I have thought of that too.
Not for myself, in my particular situation and not for the same reason...
Some people have a boiler with a wide diameter. And have a problem with leaving enough height of liquid
in the boiler to well cover the electric element at the end of the run.
You could cut the bottom off and weld a second, MUCH NARROWER vessel on.
Thus needing a minimum liquid to cover the element.
And simply done for those who weld.
GeoffThe Baker