Better Operation of a Brew Shop CM Still (novice guide)

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Cong
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by Cong »

If I swap it out to say 2KW how would this go with a final run?

I have access to a hotplate that I can run in conjunction of about 1KW taking to a total of 2.3 KW.
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by kiwistiller »

you'd probably want to swap back to the other one for a spirit run, but you never know? it isn't hard to swap them, you could try both ways. if it's fine going fast for you, great, and if not just shut it down and chuck what you've collected back for redistillation. I can't validate this from my own experience, this the brew shop guy around here said that the still shouldn't be powered from underneath, as the metal wouldn't stand up to it for long. he might have only been referring to propane though.
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Cong
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by Cong »

Thanks Kiwi,

I guess just suck it and see, but from what I conclude here is that more heat will definately help with a stripping run and most likely is a good thing.

Am trying to get together a VM for spirits runs.

cheers

Cong
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by airhill »

Cong

I have one of those 25l boilers with a 1340w element. Only put about 18-20l in it but its up to temp in an hour and I'm done in 4hrs being slack and 5hrs being careful (running wash to 92% abv). Thats with a bigger column and packed with ss scrubbers and refluxing. There is something wrong if its taking several hours for a strip run.
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by Cong »

It looks like the extra heat worked a treat, stripping is at a much more acceptable rate now. Couple of hours after heat up and of course heat up time is greatly improved.

Stripped 3 x 25 L washes, got around 18 litres @ approx. 60 %.

Ran the spirit run, adding approx. 6 litres hot water to cover the element, no additional heat.

Got around 10 litres, 5 litres at 92% and 5 at 90%, used sodium carbonate, around 1 litre heads, and hardly any tails.

Only mod is SS scrubbers, bloody slow run took about 10 hours.

Not bad results for a little unit
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by kiwistiller »

Cong wrote:Not bad results for a little unit
good to hear! what did you end up doing for extra heat?
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by Cong »

Used a portable hotplate 1500 watt. Boiler sat on nicely. There is a tiny gap between the hotplate and base of the boiler because of the rim on the boiler.

Don't think I'll strip and run 3 again unless I can get some speed to the spirit run, which I assume will improve with a decent column.

It is a bit hard to spare 10 hours, however I am happy with the results.

Cheers

Cong
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by kiwistiller »

remember you can stop and start the run if you get bored :lol:
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Cong
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by Cong »

I did think about that but knowing my luck, I would have shut it down just before it was finished. So I just waited and waited :|
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by kiwistiller »

Cong wrote:I did think about that but knowing my luck, I would have shut it down just before it was finished. So I just waited and waited :|
haha yip fair enough. you can calculate how much you'll be by looking at your inputs.

Another thing to think about is the lack of effort in running a strip run. turn on still and water, put a 5 liter or so bottle under the output, and busy yourself with whatever else you need to do in the shed. the total 'effort' time is really less (for me anyway).

might be worth trying to see if you can get your spirit run a bit faster with a touch more power? mine were done with 2000 watts, it handled it ok.
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by Cong »

With the extra power were you still pulling 90%?
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by kiwistiller »

yup I was getting 91-2 on spirit runs depending on how fast I ran it.
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by Cong »

Thanks Kiwi,

An interesting excercise. Incidently I used 48 hour turbo halved with 6 KG sugar in each brewed out to 990, there didn't seem to be any real defined cut over from heads that I could tell. Originally took out about 1.7 litres heads with still no defined cut over so I put about 600 ml back in with the hearts run. Not that it smelled too bad anyway.

Although I am not real experienced with cuts, my last run with a full 48 hr turbo, 8kg sugar, sodium carbonate, there was a pronounced cut at about 600 ml, forshots aside.

My product normally smells like vanilla, this new one is far less pronounced. Should neutral have little or no smell?
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by kiwistiller »

Cong wrote:My product normally smells like vanilla, this new one is far less pronounced. Should neutral have little or no smell?
Neutral to me always smells a little on the sweet side. not heads sweet, but yeah, sort of a touch of vanilla. It lessens a bit for me on airing, and I find it much easier to make cuts after that. but yeah, little smell is good. You probably won't get 'no smell whatsoever' from that unit, at least not without lots and lots of redistillations
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by fatbloke »

Well, despite kiwi's excellent guidance and response to questions, I'm still experiencing a little weirdness from my SS super reflux.

I say weirdness, because it doesn't get used that often, though I'm trying to get into the habit - it's a bit "work related" as I only really get the time at weekends.

Now here's the weirdness..... Last weekend, I ran it with just a straight turbo, approx 14% ABV. I started it about 1300 and finally switched it off at 2300. So, I've tried using it with the "ceramic saddles" in the reflux chamber, rashig rings and copper mesh. I posted before about the copper mesh and it's packing density.

This run produced about 3750mls from a single turbo wash, it measured a reasonable 87 to 88% (I was measuring periodically).

Now today, with exactly the same amount of packing in the reflux chamber, I mixed up all the turbos that had been "stripped" (including last weeks effort) and then let it down to 40% and it turned out to be about 20 or so litres, possibly a little more, I didn't measure it and was mainly focused on what % ABV I could achieve.

So I started it at 0900 this morning and I switched it off at 1500. The distillate was running out the still a lot quicker, actually "running" some of the time, other times dripping at about 2 drips per second (sorry for the imprecise measurements but I don't have much in the way of kit for exactitude....) the first gallon (imperial i.e. 4.55 litres) came out at a total of 80% ABV, the second gallon measured about 75% ABV and the final 2 litres or so, measured up at about 85% ABV. With all these mixed together (before letting down to 40% for carbon filtering) gave an aggregate of 80% - which has been let down with lower calcium (lower than tap water here anyway) spring water to 40% and I have just a little less than 25 litres at 40% ABV.

I'm reasonably pleased with the results. It's pretty clean tasting as I dumped foreshots from all the "stripping runs" and also 50 mls from this "spirit" run. Once it's been through the carbon filter it should be excellent - IMO!

What I did find weird, was that it was only coming out the still at 80% ABV. Now the same amount of packing gave me 88% last week from a 14% wash, yet todays still charge, despite being 40% ABV only came out at 80%. I don't follow why that might be.

Yes I can understand that it might come out faster, but not lower.

I've had the reflux column packed with copper mesh, that has been packed in moderately tightly with a wooden spoon handle, to approximately the same height as the top of the reflux chamber cooling jacket. With my water supply switched on full, it seems to sit almost exactly at 80 degrees C (occasional fluctuations in water pressure means that it goes up to 80.4 and down to 79.3)

Now I'm not dissatisfied with the results particularly - I just don't understand how these variations are occurring, despite trying to read through the main site, and this thread (both physics and chem teachers at school were rubbish - and I'm not the sharpest knife in the drawer either.....)

So whether I've missed something here, I really don't know.......
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by rad14701 »

fatbloke, it's all about heat input versus coolant flow with that still... The only way to improve its performance is to add a packed column extension...
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by kiwistiller »

generally, faster = lower. have a read up on reflux ratios if you want to understand this.

What power element do you have in there mate? it does sound a bit slow.
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by marc83 »

This thread has been very useful to me along with the tried and true section,thanks for the explanations there Kiwi.

Just a quick question on the cooling,I have rigged up the same cooling inlet the same as Teddysad's in the previous posts,but was wondering if i plumbed a Y-connector to separate and control the cooling flow to both the product condenser and column,would there be any benefit in this??
Just got me wondering while i was carrying out my first spirit run on 20L of 35%abv BW low wines.Collected about 6.5L @92% of good stuff,threw out a good 100ml of foreshots and collected 200ml of heads..
Anyway,the reson im asking this is because even though my temps were sitting steady at 77-78 degrees,the coolant flow was not quite enough to fully cool the distillate,if i turned up the cooling flow i would drop a few degrees.So i thought maybe two separate inlets may work with control over each??

I think i saw something similar on previous posts but was not on a Store bought CM still like what i have so didnt know if it was right,Any comments are appreciated
Cheers all.
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by LWTCS »

I'll jump in and say yes. Any time you can add an additional layer of control you increase the likely hood of higher abv.

I have an irrigation system that can supply fresh cool water and (via bi-pass valves) recycled product condenser coolant also.

I can shut down the product condenser to feed fresh water or supply fresh (cool) water directly to the (CM apperatus) dephlag.

I can shut down and /or drain the dephlag during operation.

Am I a valve jocky? Not for long. Just looking for the multiple sweet spots
as my still is a bit of a,,,,,,,freak.

Just my perspective (at present).
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by marc83 »

Cheers L-Dub,
A bit of modifying before my next run me thinks.Gotta try and get the most i can out of this still.Yesterdays spirit run combined with the past few weeks strip runs have realy jumped up my understanding of how the still is working etc.The ol brain ticks over while your monitoring the still. :ebiggrin:
I feel sorry for people who don't drink. When they wake up in the morning, that's as good as they're going to feel all day.-Frank Sinatra
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by kiwistiller »

to be honest I'm not sure you'd see much in the way of effect as the product condenser in those stills has plenty of capacity to spare, but it won't hurt at all, and if it helps you understand whats going on, then do it :D
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by snark92 »

Back a page Kiwi suggested you can turn the still off & start again tomorrow.
This is also suggested elsewhere when people have really big washes. Never heard anyone complain.
I tried it last week. No way. Had a horrible smell, not in any way bad because of metho, nail polish or jet fuel type bad. Just bad.
Tried all different temps, gave it 2 hours of mucking around. Not worth anything.
It was a birdwatchers 23l wash & the night before when turned off was still producing fine.
That's what happened to me.
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by kiwistiller »

strange. did your temps stabilise normally? It's a fairly common thing to do. how long did you leave before running again? could you describe the smell in any way more than 'bad'?
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by snark92 »

Kiwi,
you may have noticed in other posts I have a t500 still much to most's disgust, but thats what I've got.
Yes temp at the top was 71, temp out average 55.
let it run total reflux, about 35 out, for about 15 mins then started distilling. awful. Tried total reflux for about the same time. Same result.
Sorry, can't really help much more with the smell as I didn't think much about it at the time & only found this thread during the week.Should have paid more attention, but can only say it didn't seem worth persuing & wouldn't trust it even for tails.
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by kiwistiller »

Sorry, I mean how long was the still shut down for?
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by moodie007 »

I have one of those CM HomeBrew Shop stills :(

Looking at building Bokakob's 2" LM.

I was considering keeping the CM head for doing stripping runs and using the LM for the final run.

I was going to use the CM's boiler and lid.

The question is, do you think the CM's 2kw 24l boiler is too small??
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by kiwistiller »

Personally, yes. well the 24l at least. I'd think of it as kinda a bare minimum.
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by moodie007 »

Thanks for the quick reply. :)

So if i wanted to use that boiler Id be better off building a 1.5", correct?
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by kiwistiller »

I personally don't think you'd ever be better off using 1.5, unless you mean cheaper. It might be easier though. Seriously, for the second hand value of it, you'll be able to set yourself up a keg boiler, boka, and probably a gas burner or element.
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Re: Better Operation of a Brew Shop CM Still (novice guide)

Post by moodie007 »

kiwistiller wrote:I personally don't think you'd ever be better off using 1.5, unless you mean cheaper. It might be easier though. Seriously, for the second hand value of it, you'll be able to set yourself up a keg boiler, boka, and probably a gas burner or element.
Thanks for your time. Looks like there will be a CM on trademe soon :)
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