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not quite 96% and a sweet taste to my neutral


needmorstuff

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I have a 20 plate still using "pro caps"

charges still with 90L of low wines at 30% made from raw wheat and enzymes, stripped through a copper pot still.

75L of the low wines had a really nice clean ferment in 2 days. SG around 1065, finished dry. My hydrometer aint that good to argue a few points..

25L of the low wines had a bit of a less clean life, they were from a 300L batch that didnt fully convert and my SG was 1060, it finished at 1030.

The plate still works great, i heat up on 10kg and then switch to 5kw, open dephleg up full for 45 mins to stabilise. All plates loaded, none flooded i can see.

take 4.5L off slowly

take the rest at 3L per hour

Took 16L in 26 jars at 95.57% (as measured with a SNAP 41)

Head temp was 77.7 the entire time (not calibrated thermo)

Left it all to air with a lose lid for 24 hours.

The first 6L at least are unusable, acetone etc.

the next 1L questionable as when i water it down i can still smell quite a strong sweet smell.

Then all the rest of it still has a slight smell when comparing to bought in GNS.

 

So It's not 96% is my first issue, and the smell is my next issue. It all tastes fine after that first 7L.

I wanted to get it analysed so spoke to a guy at Tatlock and Thompson an analysis company who said i can't get 96% from a 3m column, I told him i had 20 plates and asked if he knew what a plate was? he lost his sh1t and hung up on me. D1ck.

So how do i get that 96%? am i running it too fast?

Should i swap out some plates and use some packing? (I've used SPP before with good results)

The smell - is that an issue? (difficult one I know... hence why wanting to get it all analysed)

 

Two steps forward, one step back!

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The smell and large heads cut suggests poor ferments. What was the temp & yeast strain of the mash that finished dry? It seems likely to me it was too hot and the yeast produced off flavors. And obviously the half fermented mash could have had any number of issues/flaws. As for the 96%, my question would be did you measure each jar as it came out, and when was the anton par last calibrated.  

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I do need to lower pitch temp, I was struggling with my useless steel immersion wort chiller. I'll get a counter flow to improve that.

I've ditched the first 4.5L so I'll likely run it all again for the practice, this time slower to see if I can hit 96 %, if I can't then I'll look at packing in part if my column.

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17 hours ago, SlickFloss said:

I agree with a lot of what Andy said from a fermentation stand point.

Love this rig!  Where are you at in terms of elevation above sea level? It doesn't appear you're running a YDO, vacuum pump, or venturi, si?

I also agree with fermentation comments.. I need to pitch colder and get to pitching temp quicker! It takes hours with a crappy immersion cooler, so I'm currently looking at either a counterflow or a plate chiller. My wort is quite clear as I brew in bag but I'm still leaning toward a counterflow for ease of cleaning. For 170l something like a 250kw plate or a 9m steel counterflow.

 

I'm 12m above.

I'm not running any of those things, or at least I don't think I am.

I was collecting at 3.2litres per hour.

I have rerun it after ditching first 4.5L of the run.

Even if I slow it down to 1.8LPH I only get to 95.85%

 

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  • 2 weeks later...

ran it all again, at 2L an hour, allowed much better separation.

Some of it hit 96%, some didn't.

On another topic, can anyone point me in the direction of a paper that shows what concentration of fusel oils are permissible in Vodka? acetone/methanol etc.

*edit, think i found it https://www.legislation.gov.uk/eur/2008/110#:~:text=This Regulation lays down rules,geographical indications of spirit drinks.

Extract of paper

image.png

 

Results of my analysis

image.png

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IMHO, long periods of 100% refluxing is counterproductive and will create more heads (ethyl acetate mainly) through Fischer esterification in the still (yes, even without catalysts).

Your small pot volume to total column hold-up volume might be making this problem worse if there isn't enough ethanol to dominate the entire column volume, the minute some higher boilers (acids) make it to the lower plates, ester formation becomes likely again due to the ethanol concentration, and these esters very easily dance there way up through the column once formed (late in the run, not early).  I'd be running that kettle completely full on a vodka run (I'm hoping your not).

Both of these phenomenon will be worse with dirtier ferments (more carboxylic acids formed during fermentation).  Ferment cool and as quickly as possible.

Don't strip deep into the tails on a less-than-perfect fermentation if your end-product is vodka.  You can always cut the heads on your finishing run, that's easy, what you can't cut easily is when you have a large amount of acids in wash/strip, these will always want to form esters during distillation, and they will form throughout the run (and are impossible to cut), requiring another distillation.

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thanks Silk, really helpful comments.

I am presuming these numbers are bad in my analysis received back?

I don't understand this "I'd be running that kettle completely full on a vodka run (I'm hoping your not)." - you are saying you would, but hope I'm not? what am i missing..

This run was combined from an atrocious ferment (300l of partially converted and started fermenting very hot, 35c, result 30 litres of strip at ~30%) and a hot ferment (300L great conversion but again started very hot 35c, result 70 litres at 33%) the end result was 100L @ 32% abv.

 

Is there any hope for this liquid? I am more than happy to ditch it if not. Would carbon filtering help? 

Is carbon filtering an essential requirement?

 

My problems here are down to two things

1, bad enzymes now resolved for second ferment.

2, Hot ferment - I need a better way to get to lower temps after my conversion, I'm on that - I am either going plate chiller or counter flow as my current immersion is terrible.

 

Is my column, a 4" 20 plate column on a 100L boiler fit for purpose? I am happy to swap it out for 1.5m or so of SPP

 

Thanks for the info on exsessive column refluxing.. i did hold it for at least 40 mins, in future i will not bother.

This is a lot harder than I had hoped, but i love learning and the journey, and never give up.

 

GNS analysis for reference

image.png.07256cbba5d1e715abf14a75da8af767.png

 

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Sorry, too early.

 

2 hours ago, needmorstuff said:

I don't understand this "I'd be running that kettle completely full on a vodka run (I'm hoping your not)." - you are saying you would, but hope I'm not? what am i missing..

I was hoping your still volume was greater than 100 liters, and that you were just running your still underfilled.  Sounds like increasing batch size isn't an option.  If you followed the hobby community a decade or so ago, you started to see this pop up as soon as triclamp/modular columns become available.  Folks were stacking plates as high as they could on really small stills, and not necessarily seeing a material improvement in quality, and in many cases not necessarily seeing a material increase in ABV/Proof.

The bigger the column, the more liquid necessary in the column to operate.  Since the column is running like a kind of sorting machine, if you don't have enough material to sort, it's irrelevant how many plates you have.  This is of course an exaggeration, but if at the top of the column you have heads, and at the bottom plates of the column you already have tails, good luck achieving acceptable purity.  You might be able to hit acceptable proofs, but you'll never achieve high purity.

My recco is that you need more alcohol in the pot.

2 hours ago, needmorstuff said:

I am presuming these numbers are bad in my analysis received back?

I didn't even look at that earlier, yes, your ethyl acetate is very high.   Ethyl acetate is detectable at as low as 10-20mg/l, and obvious/objectionable at 150-200.  You are well in the ballpark of many rums at that point.  What did you provide as your sample?  Was it vodka at 80 proof, or high proof neutral?  I'd need to do some math to convert the numbers to compare.

Otherwise, not fantastic, but not terrible either.  Many vodkas have flavor and congeners.  If you were distilling pharmaceutical alcohol, that's a different story.

2 hours ago, needmorstuff said:

Is my column, a 4" 20 plate column on a 100L boiler fit for purpose? I am happy to swap it out for 1.5m or so of SPP

 

This isn't your problem.  There is no substitute for hands-on time on the still and at the mash tun, focus there.  Don't be afraid to dump a batch and start over, that's how you learn.  You are trying to overcome a bad ferment, which might very well be a futile exercise.  Garbage in, garbage out.  However, use it to your advantage, redistill it.  Redistill it a few times.  Play around with different concentrations.   Play around with different operating conditions until you find the sweet spot of the rig.  Ask this question again after you've run it 100 times.

 

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this was analysed at 80 proof so my ethyl acetate would be around 250 at 200 proof. So bad. Honestly i was mostly concerned by furfural because im at 200mg/l at 200 proof and the EU spec says "not detectable" which i interpret as you cant have any! also the GNS COA i added has no value next to furfural.

 

moving forward I could run my stripping still through plates to get the abv higher, to allow a higher abv boiler charge for my spirit run. at present it was around 65 proof. If i strip through my plates i could charge way above any safe limit.. so could maybe settle on 80 or 90 proof in the boiler at 100L. Does that sound like a plan?

I am aligned with you on 100L boiler on a 4" column with 20 plates... that's a lot of volume for my boiler, this is why i was thinking a shorter column with SPP would be considerably less volume to fill and perhaps offer a more balanced rig.

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Mashed in again yesterday, 56kg wheat, total volume inc water around 230 litres.

 

My target was a good conversion and a pitch temp of 26c. To aid this i bought a counter flow wort chiller https://www.themaltmiller.co.uk/product/counterflow-wort-chiller-tri-clamp-304-stainless-steel/?v=79cba1185463

All going well until my crappy pump quickly exposed itself as a weak link, flow was so slow https://www.polsinelli.it/en/electric-pump-for-beer-novax-20-b-P1041.htm

This thing started to smell of burning and flow rate was terrible.

I eventually went back to my immersion cooler (also rubbish) and ended up having a very late night getting pitch temp down to 27c. I had to dump ice into the wort to get it to that.

It's fermenting nicely today, sweet smells of bread and molasses and a rolling krausen on top.

Thinking back, i did take ph reading prior to adding AA and GA, but i should have taken a ph reading AFTER dumping the ice in.. but it seems to be doing its job and ph was 5.1 today.

The counter flow wort that was exiting was around 24c at the start so it seemed to be doing its job well with a water inn temp of 17c... just need to invest in a mash pump now.

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stripped 3 ferments (56kg wheat in 260l total volume). start temp for all was 27c i measured and when i did ferment had climbed to 33c

stripped through my 300l still each time through 4 plates quite fast on around 10kw of power, collected at around 90 down to 40% abv

cut heads (200ml) and tails on each strip and collected around 16 litres of pure alcohol (20l @ 80%) each run. switched off after 20L collected and measured 40% abv

Now charged my 100L boiler with 100L at 50% abv and running that, heated up on 12kw, running at 6kw.

Collecting at 3L per hour. abv between 95.56% (calibrated snap 41 at close to sea level, 12m)

I'm collecting at 4l per hour because at this speed it will still be a 11 hour day, (1 hour to heat and 7.5 hours to collect 30 litres of liquid). If i can't fit this into a day then there is something fundamentally wrong with what i am doing or my kit.

I had a play around with speeds when collecting. start this after collecting 4.5L, so well into the run.

at 2.8lph i get 95.8%

at 3lph i get 95.56%

at 3.35lph i get 95.69%

at 4lph i get 95.57%

 

I'll make my cuts tomorrow and send off to the lab for analysis again.

 

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running it now, im about 15 litres in. Far less heads, collected first 10l in 1l jars, took next into 2 x 5l tubs, after that switch to 1l again (sooner if i detect any tailsy smells.

Seems far cleaner, but ill leave it until tomorrow to be subjective... will water down samples with some warm water in a nosing glass, and have a taste also.

Being the first lot i will sell, ill still send it to the lab..

I'm certainly getting good at mashing now 😉

Just need to get a better pump so i can get the temps down quicker and better through this counter flow chiller.

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@Silk City Distillers i couldn't wait 😉 I have made a healthy additional heads cut of 7 litres. I used a sample from much further into the run as a test sample, comparing heads to this for taste and smell. When there was less of a smell in the earlier portion of spirit i made the cut (7l). I did this test with other people.

Interestingly, most noticed a more caramel type odour from the sample further on into the run (11L) than when i made the cut. I also detect this. With the cut sample having less odour.

I have probably cut too much, and may cut more tomorrow, but i'd rather that than introduce anything that's going to influence the end result.

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