CM Still Temp problem (maybe)

[gad]

G'day Guys

Doing the best I can with what I have, I have one of these HBS bought small 25L stills.

http://i41.tinypic.com/30ubz9c.jpg

Had run it for app 5 years before coming by this site (wow, what a revelation) using Dextrose, Turbo's (all the HBS gear) etc.
The flimsy instruction with the still said to run it at 78 deg, which was fine & what I did for years.

From reading threads on this forum I took the packing (ss scrubbers) out of the column & ran a few TPW stripping runs.
I repacked the column with a couple of new packets of ss scrubbers (looked identical & looked like exactly the same amount) & ran a spirit run.

The temp showing on the thermometer ran pretty much the whole run at 72.5 deg, the spirit coming out at 90%. It actually started spitting out the foreshots before I was ready, mid 60's or so from memory (may be earlier? I wasn't in the garage when it started).

At around this time I put on the hose connecters etc to make changing from stripping / spirit mode a lot easier (heating up the hose to pull off & put on the barbs wasn't very efficient).
I re-packed the packing thinking this could be the only possible reason for the temp diff.
I then ran a single TPW spirit run which also ran at 72.5 deg. Turning the cooling water way down, even off, didn't raise the temp above 72.5 deg.
I then took out the scrubbers, stripped another few BGTWB's (temp range app 79 - 89 deg), repacked the column only this time I did not pack up past the columns PC exit hole (left a gap at the top of the column).
Spirit run again ran at 72.5 deg * came out at 93%.
Now 93% for one of these small CM stills isn't too bad IMHO so I'm not complaining, I'm just wondering if extracting at 72 deg is going to affect the final product as that original instruction sheet said the best product is extracted at 78 deg. (though I'm thinking it must be up around the 78 deg mark or it wouldn't be extracting ... thermostat wrong?)

The stubby holders wrapped around the column couldn't be causing this, could it? Only other thing I can think of.

Any opinions or am I just being paranoid. Many thanks.

[Kimbo]

Hi Gad,
Some of the members here who use one of these regularly, should chime in too
But here's my take mate:
1. don't ever leave your still unattended
2. yes the stubbie holders will have some impact on the operation of your still.... how much? i dont know ( but its usually for the better)
3. fores usualy do come off at around the 60 deg mark
4. altering your packing will affect the operation
5. 93% is pretty damn good
6. I wouldnt worry too much about what temp its running, more the difference in temp during the run. ie... how much it increases and when.
7. I assume your making good cuts and if your happy with the product your making that's all that counts :handgestures-thumbupleft:

Hope this helps mate

[Sam.]

Sounds like your running it properly, if that's where it wants to sit then so be it.

Most likely thing is our thermo is out, test it in boiling water and see if it reads 100 and you can also put it in an ice slurry to see if it reads zero :handgestures-thumbupleft:

[gad]

Thanks Kimbo & sam_and_liv.

Advice noted & appreciated.

Just tested the thermo first in an ice bucket - 0 deg
Then in boiling water - 92 deg only (& the water was boiling).

Looks like that is the problem. I'll pick up a new one through the week.

Thanks for the help, very much appreciated. :text-thankyoublue:

[gad]

Also meant to mention that making my cuts is what i'm finding most difficult of all.
Damn snout can't tell the diff, damn taste buds can't tell the diff but I'm trying very very hard to try & work it out.
At the moment my cuts are pretty well being detirmed by what % the spirit is coming out at.
Generally the first 750ml after foreshots is going to feints as heads & anything not long after the % drops (ie 93% down to 92%) is going to feints as tails.
On that last spirit run that still gave me 6.3L at 90% but I have no idea how much heads or tails are in it.
I did try a small drink of 1/3 40% spirit & 2/3 coke (not long after the run) & it wasn't bad so should be pretty good.
Guess I'll find that out down the track ............

[bluess57]

Thanks Kimbo & sam_and_liv.

Advice noted & appreciated.

Just tested the thermo first in an ice bucket - 0 deg
Then in boiling water - 92 deg only (& the water was boiling).

Looks like that is the problem. I'll pick up a new one through the week.

Thanks for the help, very much appreciated. :text-thankyoublue:

Also consider the
Boiling point of water here needs to be adjusted for the altitude
Scratch that thought less impact than I orig thought

[gad]

Thanks bluess57 .... I didn't know.

Looked it up - In Canberra, the boiling point of water is about 98.5C.

So still out 6-7 deg. which would explian my prob.

[fizzydrink]

I have nothing to contribute, but thought id say I like how you've set it up with the parrot etc. I should do that with mine.

Cheers

[Dominator]

I would not be to concerned about the thermometer accuracy, you are only using it as a guide. I would rely on my alcohometer more so than the thermometer. The temp in your column is directly related to the alcohol content, ie. the lower the temp, the higher the ABV. Smell and taste will be the deciding factor in your final cuts, and don't worry if your struggling, it takes time to learn.
Also, the still will run very differently depending on what it is charged with and the wash/low wines ABV. A tpw wash will be around 12%, turbo wash approx 18% and low wines will be any where up to 40%, each of these will boil at different temps and will produce varying ABV distillate.

[Kimbo]

And don't forget that CM stills are inherently harder to control,
As the alcohol in your wash gets depleted, you need to adjust your coolant flow accordingly ;-)

[gad]

Thanks for all the help & advice guys, very much appreciated.