Temperature confusion

[Opus 27]

I\'m not a T500 user but I read the various posts with interest. The thing thats confusing me is the comments on the two temperature readings. On all traditional reflux stills the important temperature is that at the head of the column. We know that when the column has got it\'s refluxing settled anything coming off before 79 degrees is rubbish and anything after 82 is also destined for the drain. So how do you establish the quality of the product by reading cooling water temperature? or am I missing something.
Opus 27

[Andy]

By keeping the outgoing water temp at (in my case) 50deg c it keeps the head temp low and steady.

If you allow the water temp to go high then the head temp goes up.

Towards the end of the run the head temp will rise so one would just add more water flow to cool things down.

Thats how it works for me anyway

[Opus 27]

Thanks Andy but how do you know what your pulling off. The good stuff we want to keep only comes off at a head temp of 79-82 above and below that are tails and head and what your saying suggest that these are present in what your producing.

[MrCat]

My thoughts on this is that with the column cooling coil running down the centre of the column and with a fixed amount of heat that the boiler can possibly supply (the 2kw element is not in the wash, it's separate) that when the ethanol quantity in the wash drops of, the column temp rises, you increase the quantity of water so that the output from the column is maintained at 50 degrees there is sufficient reflux to knock the water back, extract the max quantity of ethanol until eventually there is nearly none left in the wash.
I found this with the computer controlled water cooling on the SS reflux. I found I could increase the water flow to keep the column stable until at the tail end of the run I was getting maybe a drop every 20 seconds - and it was still over 90%..
Edited to add - of course the T500 differs differs to LM and VM columns where the cooling coil is normally above the ethanol take off - in the T500 the CM coil is beneath the take off.

[Andy]

how do you know what your pulling off. The good stuff we want to keep only comes off at a head temp of 79-82

Nothing comes out untill it hits 79.

I dont worry about head, hearts or tails as the instructions say that you dont need to do cuts.

All the spirit coming off smells the same from start to finish.

I just collect the first 100ml for wifey to use as cleaning product and the rest is mine for drinky\'s

[PhatPhucDistilling]

Well I am new to this new hobby of mine, but I seem to be having getting my water out temp set no worries at around 55-57 degrees. but I have only 3 washes and the top temp was 76 deg first time, 74 deg second time and now on the third wash it sitting at 72-72 degrees,
Is this ok to drink ?
Why is it doing this ?
What should I do
I know I am new and I have been reading all the posts and cant find any answers
any advice would be gratefully appreciated, Cheers

[Admiral Toad]

The instructions aren't the best
If you don't want to do cuts as long as you chuck away the first bit and dilute and filter the rest you will get a half decent product

BUT if you do make cuts as described all over this forum you will get a markedly better product with less chance of hangovers

It's down to personal choice and what you want to get out of this hobby

BTW I tend to run nearer 58 degrees temp but I do double distill and filter for neutral

[Andy]

Since making the above post of mine in 2010 I have changed a lot of my process.
I now strip my wash's through a pot still attached to the T500 boiler.
I then run the low wines through the T500 head and yes these days I am making savage cuts.
Anything I dont want to drink on the first run IE heads and tails just goes into the next run.
Since doing these "new" things the quality of my product has increased remarkably, filtering has become a thing of the past oh and the mornings have become clearer

[John51]

How accurate is the top thermometer wrt the type of alcohol being produced?

Have just done my first run with a T-500 and the top temp was reading 78.2' with an occasional dip to 78.1'.

78.1' being the boiling temp of ethanol I'd have thought that an increase would happen when the hearts had finished but I got a small amount of tails in the final half litre so I stopped the run and it was still reading 78.2'. Bottom temps I kept between 50' and 55'.

[Myles]

You have to remember that this still is a Coolant Managed (CM) still. Unlike the other designs the product is the vapour that manages to get PASSED the reflux condenser. On all the other designs the product is taken from BELOW the reflux condenser.

On those designs the reflux condenser has to stop all the vapour from getting past, on this one it has to ALLOW the vapour to get past.

Lower boiling point nasties (Heads) are allowed past first, whilst the condenser and the column send the ethanol back to the boiler to wait. The coolant temperature is not a precise indication - more of a guide.

The temperature referred to on other designs is the VAPOUR TEMPERATURE in the vicinity of the take off port.

Now I haven't used a T500 myself, but in general CM stills are very precise, and notoriously fiddly to get to work to their optimum potential. Perhaps the manual is a slightly "averaged" version to make it easy to run. There might be a more precise set of operating instructions available.

[lll_0_mike_0_lll]

Top has to be over 72* for anything to come out. Also make sure the top temp probe is in far anofe. To get a good reading. The bottom need be 55-65* for the smoothest best tasting you can get. Never drink 190 proof. Be sure to water it down at least to 150 proof or less.

[Myles]

One other point to mention. The issue of vapour temperature keeps appearing. Head temperature of 79-82 degrees for example.

This really isn't strictly true. For example if you are running a Vapour Managed (VM) still the ACTUAL temperature is meaningless.

Yes you monitor temperature, but are far more concerned about the STABILITY. If it rises by 0.1 deg C you need to know about it and do something. Usually this involves reducing your product rate and increasing the proportion returned to the still as reflux.

On a CM this would be achieved by increasing the coolant flow rate.

Don't be too fixated on the actual temperature (what is the resolution of your temperature measuring device and is it even calibrated?)

On the T500 start in full reflux, reduce coolant flow to start taking heads, and be prepared to adjust the coolant flow as needed throughout the run.

You might eventually develop a run profile that works for your still, in your still room and with your recipe, but change from TPW to sweetfeed (or any other combination) and be prepared to start all over again.

[Opus 27]

Thelast post puts it into a "Nut shell" it's all about constant monitoring and adjusting. When it tastes right and smells right then you have it right.