Damn blue distillate - again

[scarecrow]

I've just stripped 20 litres of my neutral wash and it has a very slight blue tinge. Never happened before with my neutral wash (I've made about 20 batches). Same recipe.
I had the last strip run of my UJSSM do the same thing. Again, after more than 30 batches, it has never happened before.

My still and all lines get a rinse with clean water before every run, and this is always checked for undesirables. It's always clean.

pH of the distillate is 4.3. It's cloudy because I strip to 10%.

The only difference I can point to is it sat a bit longer than normal because I went on a 2 week trip to Van Diemen's Land.

It went dry in 10 days and it then sat for 4 weeks. It usually sits for 10 - 14 days and then I run it. The smell in the fermenter was slightly vinegary (pH 4.4) and slightly sour in taste.

It needs to have a spirit run done, but should I dump it (and the UJSSM) and start a fresh batch. The SM is up to it's 6th gen. I start again after 10.

I've checked other posts for this phenomena, but nothing really nails it down.

scarecrow

[olddog]

Could have turned to vinegar, thats the color I get when I do a cleaning run with 50/50 vinegar/ water.


OD

[scarecrow]

I did notice that it (probably) happened towards the end of the run. It was OK at 65% when it started. It was OK at 50%. After that I stopped checking the output pot till it got to 10%, then I powered down.

There were a lot of oil floaties on top, hence the haziness.

I had a smell of the distillate and it actually has less offense than the neutral feints jar next to it. I mixed some 50:50 with feints and the blue tinge disappeared (and the cloudiness which was expected).

I'll put it aside and do a spirit run when I get my plaster off.

scarecrow

[rubber duck]

I just had the same thing happen to me this weekend, I was running my VM and got a slight blue ting. It was an all feints run and I didn't do any ph adjustments. I'm not really sure what happened.

[Bayou-Ruler]

I was lead to believe that blue tint to the lickker was from copper salts. Could have been mislead...................................

[Barney Fife]

It was OK at 65% when it started. It was OK at 50%. After that I stopped checking the output pot till it got to 10%, then I powered down.

That happens to me at times, in the "deep tails". Especially when I push hard. No problem, it won't mess up the spirit run.

I'll put it aside and do a spirit run when I get my plaster off.

Get your plaster off?

[scarecrow]

Get your plaster off?

I got a fractured wrist with a few pins in it. Not fun in summer.

I do run my strip runs with the banjo flat out. Always have. I'm thinking this started in the late tails somewhere.

The pH of my mash is always below 5.0. More often than not closer to 4.0. So I'm thinking it's not an alkaline reaction with copper.

scarecrow

[WeeStiller]

I often have the blue hue at the end of my fast stripping runs. I sometimes had clear blue particles as well. Always disappears in the spirit run. On this site and forum I read two possible causes:
1) copper salts (copper sulphate, I think) from the sulfur in the wash. It is said that this is the reason why you need copper in the still; it bonds the sulfur into a solid that can be removed by redistilling or filtering.
2) ammonium nitrate in the unused yeast fertilizer ending up in the wash and reacting with the acids while distilling. In this case, too much yeast fertilizer is probably used since it's not all used up by the yeast.

[scarecrow]

My wash is as simple as it gets.

water to 22 litres
1 kg cracked wheat
3 kg sugar
2 tablespoon bakers yeast
citric acid to pH 4.5

I'm going to flush the fermenter this arvo and start a new wash. See what happens.

scarecrow

[scarecrow]

OK, now I'm starting to panic.

I thought it was my wash that caused the blue tinge. I have just run a double batch of UJSSM and it has a blue tinge as well.
My last tainted batch was a wheat neutral, so it's not my washes or a particular recipe.

I filtered some liquid through a blank sheet of paper, and the stuff dries to blue-green crystals. It has to be coming from my still.
I have removed the copper boiling chips and all copper in the vapour and liquid path (except the still itself).

I'm too scared to run another wash for fear of killing myself with this copper sulphate crap and it's starting to get expensive for no return.

Am I stuffed? What do I do?

scarecrow

[HookLine]

Only leaves the still.

If I remember my high school chemistry right copper sulphate is formed when copper and an acid come together. And your distillate pH is 4.3.

Tried cleaning and drying the inside of the still after a run, especially the product take-off arm and condenser? Or at least flushing it out with plain water?

[still crazy]

I got a bit of that blue tint in some runs on my pot still "hextopotamus".
So I rinsed my entire unit with a solution of citric acid and salt water cleaned off all the patina that had formed in the worm coil.
Problem solved.

[scarecrow]

.....the patina that had formed in the worm coil.Problem solved.

This is where I think it is coming from, but it doesn't start going blue until well into the tails. There was a lot of oil floating on top as well.

I'm wondering.......as the alcohol depletes ie getting towards 10% ABV, the concentration of (acidic) water increases. This probably causes some reaction in the lines.

I must admit, I run the banjo flat-out so this probably doesn't help.

I've got a batch of orange rum coming off on Friday, so I might do a medium speed strip, and catch the distillate in 500ml jars. This should give me an idea of where it is happening.

scarecrow

[scarecrow]

Ok, found it. Everybody relax.

I flushed the coil out with some citric acid solution. A quick rinse and a lot of blue colour came out.

I'm off to Bunnings to get some fittings. I will make an adapter to allow acid/water flushing of the coil. Should be easier to keep clean then.

scarecrow

[Barney Fife]

ie getting towards 10% ABV

You're going too far; stop at 30-35% ABV, or slow down your collection if you want to go deeper than that, but really, you're using more energy to get that last little bit of mostly unusable alcohol than it's worth. Honest. I stop collecting at around 40%, where I'll begin to see a slight blue tinge at that point. It's normal. Don't be greedy, trying to squeeze every little bit of alky from the wash. Besides, if you re-use the dunder/backset, it's not wasted anyhow, except for the little bit you'll leave behind in that last generation.

[rad14701]

As your run is getting to the end, or well beyond what should be the end, your reflux condenser is probably sucking a lot of extra air due to the high amount of water vapor collapse... This will contribute to the formation of excess oxides and/or sulfides... Not digging so deep into the tails, as has been mentioned, should reduce or eliminate the problem...

[HookLine]

ie getting towards 10% ABV

You're going too far; stop at 30-35% ABV, or slow down your collection if you want to go deeper than that, but really, you're using more energy to get that last little bit of mostly unusable alcohol than it's worth. Honest. I stop collecting at around 40%, where I'll begin to see a slight blue tinge at that point. It's normal. Don't be greedy, trying to squeeze every little bit of alky from the wash. Besides, if you re-use the dunder/backset, it's not wasted anyhow, except for the little bit you'll leave behind in that last generation.

That slight 'blue' tinge is probably the cloudiness of tails coming through, not from copper sulphate.

You are right that when to stop collecting is a balance between yield and input costs (especially heat energy). But if you are stopping at 40% product strength that means the boiler charge still has 6% alcohol. True, any stillage left behind can be reclaimed by recycling it back into ferments (as dunder/backset). But if it is recycled then at 6% it won't leave much for the new ferment to add. If you run your ferment to 10% total (6 + 4) then the net yield will only be 4% per cycle. (Not to mention that a starting abv of 6% is not ideal for yeast.) Alternatively, throwing 6% stillage out wastes maybe half of your potential product. Either way seems like a serious waste of time and energy to me.

I always go to a product strength of 20% (98º C vapour temp), this leaves about 2.5% behind in the boiler, which means an extra 3.5% is being gathered per ferment cycle, almost doubling the yield (4 + 3.5). The amount of extra time and energy required for this is minor, commercial operations do it all the time, IIRC some go lower down to 10% product strength. Pretty sure they have figured their time and energy numbers closely. Takes me maybe an extra 90 minutes (at 2400 w heat input) to get that 3.5% from a 40 litre wash. The extra time and $ cost is trivial for the return.

Being greedy is going below a product strength of about 10%.

Edit:

[Barney Fife]

But if you are stopping at 40% product strength that means the boiler charge still has 6% alcohol.

No.

My washes more often than not start out at 5 to 6%, so there's no way that after taking foreshots, heads, and a couple quarts of product, that the wash is still at 6%ABV. I also always get 5 to 6 generations from a wash while reusing ALL the dunder, running like I said, so this again shows that the dunder isn't anywhere near as high in alcohol as you describe. Fact is, most of the alcohol comes out when we're pulling higher ABV, and by the time the still's giving us 40% at the condenser, there isn't much left. Ever notice how when you're finished collecting the hearts, it takes no time to finish collecting the tails? Even if you run it down to 10% at collection, it's not a whole lot and doesn't take very long. At best, you'll collect about a quart/liter of tails from 40% ABV to 10% ABV(assuming a 5 gallon wash/charge), which comes out to around 200ml of alcohol, most of which isn't usable, even after a re-run. You've maybe, -maybe- 'saved' 50ml, or 2oz, of alcohol. For how much effort? And of course, there's this deal with the blue shit, that you likely wouldn't have otherwise.

We can argue the merits of collecting all the way down to nothing, but what we can't argue is that the boiler charge will still be at 6% ABV when we get to the tails. No way, no how. Not on my rig, nor on any commercial(which will mostly run roughly 5% ABV washes to begin with, also) rigs.

[HookLine]

If it is a basic pot still, then for vapour to be coming off at 40% means the still charge is 6%.

Straight off the ethanol phase diagram.

http://homedistiller.org/forum/viewtopi ... =1&t=10158

To get any other numbers means you have some kind of reflux arrangement: packing, plates, thumper, etc.

[Barney Fife]

If it is a basic pot still, then for vapour to be coming off at 40% means the still charge is 6%.

You're mis-reading your charts.

I think what you -want- to be saying is that at 40% off the condenser, we still have 6% of the alcohol initially available remaining in the wash, and if we crunch some simple figures, that adds up to pretty-near exactly what I stated in my previous post. If we take an initial boiler charge of a 5 gallon wash at 5% ABV, we have 1/4 gallon of potentially available alcohol(at 100% ABV). That's one quart at 100% ABV. Six percent of this would be a hair under one fluid ounce(again, at 100% ABV). So, if you collect -everything- that comes off the condenser after 40%, you'll have collected(saved) 1oz of available alcohol(that is of course, diluted in a quart or more of mostly water). And in practice, these numbers are very close to exactly what we do get from a pot still. So, not worth the energy and effort, isn't it? And when returning this 1oz of alcohol back to the fermenter for other generations' washes, we don't concentrate and add them(IE, we won't end up returning 6 ounces in the 6th generation) because we take each charge down to the same level, thus squeezing out some of that "rescued" alky from the previous dunder/backset, thus we only return an ounce of alky each time.

[Barney Fife]

I just saw where you got mis-lead by the chart.

The chart's blue line, the liquid's ABV range is from zero to one hundred percent. It's showing the available alcohol in percentage, NOT the boiler charge in percentage. So use my numbers instead of a percentage for the blue line on the chart, and it works out as I said it would. At 100%, the boiler charge from a 5% ABV wash contains one quart of available alcohol, and at 6% on the chart, we have under an ounce(0.96oz) left.

We need to be careful when using charts and such, to be sure we're correctly interpreting them.

[ginjo]

Barney, they did have it right. 40%abv at the condenser does indeed mean that the wash is 6%.

[rad14701]

Barney, they did have it right. 40%abv at the condenser does indeed mean that the wash is 6%.

And while that may be correct, it would be based on only the volume of wash left in the boiler...

Here is a rough example... Let's start with 10 liters of 10% wash... Distilling it down to 10% ABV at the alcometer, depending on the amount of heat used, might yield ~3.2 liters of spirits... That would only leave roughly 100 ml of 100% ethanol in the remaining 6.8 liters of wash... And, as we all know, it's going to become harder and harder to extract more ethanol using a pot still because we will get more water than alcohol as the run progresses...

Now, if we use that same scenario and only run down to 20% we would end up with ~2.4 liters of spirits and 7.6 liters of wash in the boiler which would only contain ~190 ml of 100% ethanol...

How did I come up with these figures...??? With a combination of calculations from the parent site along with the Temperature : Vapor Purity charts... When the alcometer reading is at 20% ABV the amount of alcohol left in the wash is only in the 2.5% range... When the alcometer reads 10% ABV the wash is only in the 1.5% range... And these product collection figures are directly dependent on the take off rate throughout the course of the pot still run... It's nowhere near as scientifically accurate as when doing run using a reflux column... It's easy to see how it boils down to how much effort we want to expend versus the reward (pun intended)...

EDIT: Yes, there is also a way to calculate this based on measuring the %ABV of the total volume collected where you would determine the amount of 100% in the volume collected and then calculate the amount of 100% in the remaining volume of wash based on the original %ABV of the wash... But you wouldn't generally be able to do that calculation on the fly unless doing a stripping run and collecting in a single vessel... We could beat this six ways to Sunday if we really wanted to...

[Bagasso]

This is intresting. I myself have things not match up when using those charts. For example on my last run I wanted to see where I should stop the run taking into account the price to throw together a wash and the price of propane. I threw 15liters of wash at 10% in my pot still and started running and these are the numbers:

----------Collected------@100%
9:59 - 42ml @ 90º = 26.8
10:25 - 568ml @ 91º = 346
10:54 - 417ml @ 92º = 240
11:30 - 456ml @ 93º = 241
11:53 - 266ml @ 94º = 130
12:24 - 379ml @ 95º = 167
12:53 - 379ml @ 96º = 140
----------------------------------------
Total @100% = 1290

Now if the total amount of ethanol available in the wash is 15l X .10 = 1.5l or 1500ml and I have extracted 1290ml of the ethanol along with 1217ml of water for a total of 2507ml this means that there's 12,493ml in the pot of which 210ml is ethanol. So 210ml/12,493ml=.0169 so the wash is at 1.69% ABV. Nothing like the 6% the graph shows.

To use the chart I remember reading that you start by finding the ABV your wash is at and then move up until you meet the blue line then moving left until you meet the red line and this is the ABV your distillate shoud be coming off at. Also read it should work in reverse the problem is that according to my numbers in which dripping started at 90º means my wash would have been around 16%-17% which of course is wrong.

Seeing that theres 210 ml left in the pot I'm starting to think that it would be better to up the ABV of the wash to 12% giving an extra 300ml or 20% more ethanol up front than try to squeeze out the last 15%.

EDIT TO ADD- Looking at my notes I noticed a small scribble in the corner 1,343 which I jotted down the next morning which was the amount of ethanol @ 100% calculated from the total volume using a hydrometer which would mean that there was really only about 157ml of ethanol left in the pot. The calcs I did during the run where done using the chart and again they were off by almost 50ml. I'd say the charts are good for ballpark figures only.

[Barney Fife]

Barney, they did have it right. 40%abv at the condenser does indeed mean that the wash is 6%.

No.

Impossible.

Again, I often make my wash at 5 to 6% ABv, yet my heads come off in the 70% range and the hearts are coming off in the high 60's. This is in pot still mode. Run carefully, i can collect all my hearts until the low 50% range, then collect about a quart of tails from there to where i give up, around 35%. Most commercial distillers also make their wash at around 5%. Nobody but nobody sees their product coming off the condenser at 40% or less right off the bat as you are suggesting would be the case!

The chart goes from zero to 100%. If we take a 10% ABV wash to keep things simple, just change the chart to read zero to ten, so that at the start, the chart is at ten percent(instead of 100%), and at 40% off the condenser, it will be at 0.6%(instead of 6%). Do the math.... Learn to read the fuckin' charts in their correct context if y'all want to use charts.

[ginjo]

I read phase diagrams all day long for my job. And I've taken many graduate level courses on phase transformations and kinetics. I'm not going to be a cock about this - I'll leave that up to you.

http://homedistiller.org/theory/theory/strong" onclick="window.open(this.href);return false;" rel="nofollow

How about you try typing in 6% wash into the calculator...?

[Bagasso]

Hi ginjo, I went to the calc and punched in 10% (what my wash was at in my post above) and I got 55% which should be coming off at 93ºC but in the numbers I posted you could see that I had already collected over a liter of distillate by the time the vapor temp got to 93ºC. I don't know why but things just don't line up with the charts.

EDIT TO ADD: Just wanted to point out something that Barney keeps repeating and it seams is being overlooked. He starts with a 6% wash so after hours of producing vapor and liters of distillate pulled out how can it still be at 6% near the end of the run?

[ginjo]

Are you sure the wash is 10%? If so, some passive reflux can increase the percent ethanol at the top of the still, and hence in the distillate. Other than measuring initial and final gravity, you can look at the temperature of the boiling wash and calculate your ethanol percentage in that wash. Remember as well that you must compensate for any deviation from the temperature that your proof hydrometer is calibrated at. Mine is calibrated for 60degF. If the booze is warmer than that, it will give a false high reading. As is often stated here, there isn't much to be learned by having a thermometer at the top of a pot still. If anything, measuring the temperature of the boiling wash can be a useful parameter. Using the phase diagram, this gives you both the %ethanol in the wash, and the %ethanol in the vapor just above the wash. Accurately measuring the %ethanol out of the condenser will give you an idea as to the amount of reflux you're getting from your pot still. I tend to get very little passive reflux in my pot still.

[HookLine]

We need to be careful when using charts and such, to be sure we're correctly interpreting them.

We certainly do.

[Bagasso]

ginjo,well I'm sure that my wash is 10% and I have checked my hydrometer on distilled water and 5 different commercial products because when I first got it it seemed off. Turns out that although it says its calibrated to 60ºF the water and commercial likkers only read correctly at 84ºF so that my hydrometer is off by 24º.

Now my thermometer is off by about -2ºC. Of course all the measurments I gave in the numbers above are corrected.

From what I learned here the temperature that a thermometer shows is the temp of the vapor flowing past it. It may not tell you how good or bad it may taste but it does let you know the temp so that together with the chart you should be able to calculate the ABV. It takes the vapor less than a second to go from above the surface of the wash to the begining of a coil. The parent site talks about vapor moving at 28cm/sec to over 100cm/sec that means that the vapor just above the wash will be flowing past the thermometer at the top of my 8 inch empty riser in .25 to 1 second before dropping into a coil in a bucket. Since you can see from the numbers posted it takes around 30 minutes for the temp to change 1 degree I'm sure that even at the top of an avarage riser the calculation should still be pretty close to the vapor just above the wash.

Now there is passive reflux but I doubt that my riser offers enough to take the distillate from what the chart indicates it should be at 55% to what the thermometer says it is 69% to what the hydrometer says it really was probably around 73%. AT least for the first liter.