First reflux run - advice / thoughts needed

[Airlift90]

Hi All,

I have just run my new reflux column for the first time last night. The column is 2”, just under 1m packed, then deflag, over and into condenser which sits on a 50l keg.
I’m going to explain what happened in the hope that some more experienced members and either validate my thoughts or tell me what’s actually happened.

So everything started well as I heated the 20l sugar wash, I held it in full reflux for 5 or so minutes as I turned the power down from 2500w to ~1kw. Then I started to slow the cooling to the deflag. I collected foreshots and heads at about 93%abv, I collected 200ml total of this and the abv dropped to 91ish.
After about 400ml of definite hearts the head temp had risen, the abv dropped and the smell / taste of the start of tails came in. I thought this was the start of the end of my run. I then realised that it couldn’t be as I should be getting more hearts than this. So I went back to full reflux and then tried again, I got a short spell 100ml or so of hearts and then again the tails. I should mention that the output rate for the above was a broken stream.
I then dropped the power down to about 850w and tried again… back to hearts for a good 300ml but the rate was much slower, like a drop a second.

My question… did the early tails come in because I was putting too much power in and forcing the oils over? The output rate for the last 300ml of hearts seemed extremely slow, or is that what I should expect? Should I have spent longer stacking the column? Does anyone have any other tips / observations on what I did right / wrong to improve?

Quite a loaded post, thanks for reading / in advance for any help!

[Yummyrum]

I think that you had the power down way to low .
Taking off @ a broken stream is kinda helpful but do you actually know how many mls per min or litres / hr ?

A broken stream sounds like around 1.5 litres an hour . Too little power and taking off too fast means there is little reflux returning down the packing . This means low ABV and tails taste coming through .
I run my 2” reflux still with close to 2400w . Collection rate is around 1litre /hr .

Not that I watch a lot of thermometers these days , but climbing head temp backs up what I’m thinking .
Turn up the power, turn down the take off rate .
More power means more vapour hitting the deflag. The more it sends back down , the higher your quality .

Also , if you strip your wash first and only run low wines in the reflux still , you will end up with a vastly superior
product.

I would also suggest leaving the still to equalise for at least 15min minimum and closer to 1/2 hour before starting to take off Fores and heads .

[Saltbush Bill]

Using the word deflegmator indicates a Cooling Management still so I will assume that what you are using is.
I think Yummy is right , not enough power.
I also think you need to full reflux at the beginning for a bit longer to compress fores..10-15 min....should be adequate.
93-94% is the minimum that still should be running....any less and your running to little power or drawing product to quickly
Both situations amount to not enough reflux.

.

[Airlift90]

Wow thanks for the quick replies. That is so interesting… I suppose my thoughts were still on a pot still and how running slower cleans it up but what you guys are saying makes a lot of sense for a reflux.
Yes cooling management column.
Ok, onto the next run, longer to balance the column, more power and dial in on the deflag cooling to aim for about 1l / hour.

Thanks very much! I can’t wait to get my eye in!

[Saltbush Bill]

I think your on it

Thanks very much! I can’t wait to get my eye in!

Dont over think it , just get it dialed into where you are getting the highest ABV possible and keep it that way.
Are you running a thermometer at the top of the column?......a drop of 1C or less in temp is an indication of tails , or that you are collecting product to fast.

I suppose my thoughts were still on a pot still and how running slower cleans it up

Two very different stills doing two different jobs .
Report back sometime soon and let us all know how it went .

[Salt Must Flow]

Just remember that 'power input' is what regulates how much vapor rises up through your column/packing. Your reflux condenser condenses it all and forces it to all rain back down on to and through the packing. This is called '100% reflux'. Allowing this to happen over a period of time will allow the lightest, most volatile vapors to accumulate at the top while the heavier, lower volatile vapors form fractions below. Blast that column with way too high of power, destabilizes the column. Operate at way too low of power and taking off product too fast will destabilize the column.

Think of your reflux condenser and your packed column as though it is a waterfall running constantly. Once you've stabilized your column (most volatile at the top), simply allow some of that top vapor to slip past your dephlegmator. Allowing a little vapor to slip past your dephlegmator is like sampling a little bit of water from the top of the waterfall. It's really that simple. You should operate at that power setting steady throughout the entire run until you shut down. Your column will be like a waterfall, raining reflux down onto & through the packing as hot vapors are rising continuously. All you'll be doing is 'taking-off' from the top of the column where it's the purest. A lot of people like to install a Tri-Clamp sight glass at the top of their column below the reflux condenser (or dephlegmator) so they can actually see all of that reflux raining down through it. It's pretty cool. You'll see that what you are taking off is just a tiny fraction of what is raining down through the column.

[MooseMan]

Different still type as I run CCVM, but you will get some good insightful information on your early reflux attempts, by reading all the advice I got when I asked how to get the last few purity points out of my reflux setup.
The thread was titled "Chasing the last 2-3%" and got some amazing input by guys here who can run packed columns in their sleep

[Airlift90]

Amazing guys! I can’t say how much the words of wisdom help clarify things.
I was just reading back through my notes from the run and there is still something bothering me. So first some disclaimers, I know that temperature is not the be all … I also now understand I was not using enough power + cooling (reflux). Ok with that out the way, my head temp was at 75C when getting the highest and cleanest output (all beit slow output), when the temp rose to 78C this is where the output dropped the abv and the tails flavour came through. Is 75C not too low? Should I be able to run at a head temp of 78C and still get clean product?
I suppose I am asking, with the advice above taken on board, what kind of head temp should I be seeing? Just as a point of reference rather than a target to hit.

[Yummyrum]

Out of interest where is your thermometer ( above or below the Deflag ) and what kind is it ?

I never take the actual temp as gospel .I don’t know what or why , but I can do two runs with the same low wines and the temp might be 79.0 °C on one run and 77.5°C on the next . What is constant is that it “hangs” at the same temp for the whole of the run only suddenly going up after tails arrive.

I asked about the position because if it is under the deflag , it can get “rained” on and the reflux can throw the readings unless you have a shield over it to deflect the reflux .

[shadylane]

So everything started well as I heated the 20l sugar wash, I held it in full reflux for 5 or so minutes as I turned the power down from 2500w to ~1kw. Then I started to slow the cooling to the deflag. I collected foreshots and heads at about 93%abv, I collected 200ml total of this and the abv dropped to 91ish.
After about 400ml of definite hearts the head temp had risen, the abv dropped and the smell / taste of the start of tails came in. I thought this was the start of the end of my run. I then realised that it couldn’t be as I should be getting more hearts than this.

"I then realised that it couldn’t be as I should be getting more hearts than this"

Your right, about the amount of alcohol you should have got from what the yeast made.
But you ran your CM still wrong. Power the boiler like it's a pot-still.
In other words, run it hard but don't over power the rest of the rig.
Then vary the dephleg cooling water for take-off rate vs ABV.

On a side note.
Do a stripping run, dilute then make the best out of a packed column.

[Airlift90]

The temp sensor is above the deflag, and think it’s a NTC thermistor. Sounds like once I get the power and cooling right the temp will stabilise where ever it wants

[still_stirrin]

When you turned down the heat input, you reduced the vapor production. And you also reduced the coolant flow to the reflux condenser, which allowed more of the produced vapors to advance to the product condenser. As a result, less reflux occurred and the purity fell, resulting in an increase in the head temperature and off-flavors appearing at the spout (product outlet).

So, as others have advised, keep the heat input high, but not too high to exceed the optimum vapor speed in the column and keep the reflux condenser coolant flow up enough to knock down the vapors. This will hold the reflux ratio high and keep the purity high as well. Remember, purity depends on the reflux ratio and the vapor production rate is proportional to heat input.

You can monitor the performance (effectiveness/efficiency) of the stillhead with the thermometer in the head (above the reflux condenser section). When the temperature rises, purity is falling and you should increase the reflux condenser’s coolant flow. But don’t reduce the heat input because you want to increase reflux (condensing and reboiling in the column), and that needs vapor production to work. But keep in mind, as you extract the alcohol from the boiler the head temperature will tend to increase and the product flow at the spout will slow, as a higher reflux ratio is needed in order to maintain the high purity at the spout.
ss

[Airlift90]

Just wanted to say thanks to all.
I ran another wash today and of course your words of wisdom nailed it! Solid 95% abv run from start to finish.
I ran more power, about 2.1-2.2kw from first drops through to tails and more coolant through the deflag. Head temp above the deflag stayed constant at 75.4 all the way until rising to 75.6 when I smelt and tasted first of the tails. At that point abv dropped a point so I collected a bit more into a faints jar until I needed to stop the run to get some work done.

One thing I struggled with was picking up on the heads to hearts this time. But I played it safe so I think I have a nice clean neutral.
Have another bucket to run once it’s cleared so… practice makes … better.

[Saltbush Bill]

Have another bucket to run once it’s cleared so… practice makes … better.

Start stripping and then running low wines.....it will make a significant improvement to your end product.

[Tōtōchtin]

When you turned down the heat input, you reduced the vapor production. And you also reduced the coolant flow to the reflux condenser, which allowed more of the produced vapors to advance to the product condenser. As a result, less reflux occurred and the purity fell, resulting in an increase in the head temperature and off-flavors appearing at the spout (product outlet).

So, as others have advised, keep the heat input high, but not too high to exceed the optimum vapor speed in the column and keep the reflux condenser coolant flow up enough to knock down the vapors. This will hold the reflux ratio high and keep the purity high as well. Remember, purity depends on the reflux ratio and the vapor production rate is proportional to heat input.

You can monitor the performance (effectiveness/efficiency) of the stillhead with the thermometer in the head (above the reflux condenser section). When the temperature rises, purity is falling and you should increase the reflux condenser’s coolant flow. But don’t reduce the heat input because you want to increase reflux (condensing and reboiling in the column), and that needs vapor production to work. But keep in mind, as you extract the alcohol from the boiler the head temperature will tend to increase and the product flow at the spout will slow, as a higher reflux ratio is needed in order to maintain the high purity at the spout.
ss

An example of biting the big dog's ankle
But you gotta stop confusing us newbies with your wrong terminology. This is a CM not a VM.
Tōtō

[Saltbush Bill]

A couple of photos from different angles , of the still in question would be very helpful.........everybody would then know exactly what they are dealing with.
Saves a lot of confusion.

[bluefish_dist]

Realize that temperature will change from day to day as the atmospheric pressure changes. It can even change during a run if a front comes through. Ask me how I know this, almost had to rerun a batch due to low abv.