Gin Run Yield

[stillgeoff]

Hi,

I've been an interested reader on here for a while and have got some incredibly valuable advice from you all! I've actually got a question of my own this time so hopefully someone out there is able to help me out!

I'm interested in finding out about people's experiences of yield during a gin spirit run. I'm getting an efficiency of 55-75% when comparing the alcohol going into the process to the final product. This is a bit of an issue because I'm using NGS which I buy 'duty paid' meaning that I am effectively paying tax on a lot of alcohol that is then lost in the process. Below is the steps that I follow (using an example run for numbers) and it would be great to get some feedback!

The process:
- Dilute 96%ABV high quality NGS down to 50%ABV
- Macerate 21.6g of dried botanicals in 720mL of the 50% mixture (30g/L) for 48 hours (note that this uses 360mL of pure alcohol)
- Strain the botanicals and dilute the liquid down to 30% (giving around 1200mL)
- Run through a 3L copper pot still using a 500W plate with additional botanicals in the vapour basket

Results:
- Distillate sits around 85%ABV for the first 200-220mL then drops quite quickly
- Tails cut taken at approximately 87 deg C and 65%ABV giving 518mL of gin when cut down to 42%

Notes:
- The final product (after cuts) contains a total of 218mL of pure alcohol (meaning an efficiency of 60% compared to the 360mL that went in)
- I continued running the still until it got to 99 deg C (and distillate down to 5%ABV) to get data and I ended up getting 258mL of pure alcohol out of it (72% of the total that went in).
- There was 647mL of liquid remaining in the still and I measured it at 3.5%ABV giving another 22mL of pure alcohol. This means that in total I got 258mL through the still and had 22mL left so I am missing 80mL of alcohol! This missing portion is 22% of the total that went into the maceration so it's not an insignificant amount.

I don't believe that the system has any leaks but if this is the case then my only thought is that the alcohol must be getting absorbed by the dried botanicals. With this assumption in mind, I weighed the botanicals in the vapour basket at 83g going in and 129 coming out so they definitely absorbed some of it.

Questions:
- Is this yield percentage normal?
- Do you think the biggest consumer of alcohol is the botanicals absorbing it?
- Would I get a better yield if I put the macerated botanicals into the still rather than straining them out?
- Does anyone have any advice on how I can increase my yield without a significant impact on flavour?

Sorry for it being such a long post but thanks for taking the time to read it!

[NZChris]

I always run with the botanicals in the boiler and/or basket. Doing that captures flavors and alcohol that you are throwing out.

I just calculated the yeild of my last gin at 79.5% of the original ethanol.

[Will Stilltry]

Hi,

I've been an interested reader on here for a while and have got some incredibly valuable advice from you all! I've actually got a question of my own this time so hopefully someone out there is able to help me out!

I'm interested in finding out about people's experiences of yield during a gin spirit run. I'm getting an efficiency of 55-75% when comparing the alcohol going into the process to the final product. This is a bit of an issue because I'm using NGS which I buy 'duty paid' meaning that I am effectively paying tax on a lot of alcohol that is then lost in the process. Below is the steps that I follow (using an example run for numbers) and it would be great to get some feedback!

The process:
- Dilute 96%ABV high quality NGS down to 50%ABV
- Macerate 21.6g of dried botanicals in 720mL of the 50% mixture (30g/L) for 48 hours (note that this uses 360mL of pure alcohol)
- Strain the botanicals and dilute the liquid down to 30% (giving around 1200mL)
- Run through a 3L copper pot still using a 500W plate with additional botanicals in the vapour basket

Results:
- Distillate sits around 85%ABV for the first 200-220mL then drops quite quickly
- Tails cut taken at approximately 87 deg C and 65%ABV giving 518mL of gin when cut down to 42%

Notes:
- The final product (after cuts) contains a total of 218mL of pure alcohol (meaning an efficiency of 60% compared to the 360mL that went in)
- I continued running the still until it got to 99 deg C (and distillate down to 5%ABV) to get data and I ended up getting 258mL of pure alcohol out of it (72% of the total that went in).
- There was 647mL of liquid remaining in the still and I measured it at 3.5%ABV giving another 22mL of pure alcohol. This means that in total I got 258mL through the still and had 22mL left so I am missing 80mL of alcohol! This missing portion is 22% of the total that went into the maceration so it's not an insignificant amount.

I don't believe that the system has any leaks but if this is the case then my only thought is that the alcohol must be getting absorbed by the dried botanicals. With this assumption in mind, I weighed the botanicals in the vapour basket at 83g going in and 129 coming out so they definitely absorbed some of it.

Questions:
- Is this yield percentage normal?
- Do you think the biggest consumer of alcohol is the botanicals absorbing it?
- Would I get a better yield if I put the macerated botanicals into the still rather than straining them out?
- Does anyone have any advice on how I can increase my yield without a significant impact on flavour?

Sorry for it being such a long post but thanks for taking the time to read it!

Hi stillgeoff

I am a total novice with very little experience and with a bit of a 'tech' issue of my own at the moment that I have posted about elswhere on the forum. Although not qualified to offer advice, all my efforts to date have been in making gin, so I can share my experiences with you to compare notes and see where our results differ.
My interest was not in wanting to produce large quantities of any one thing at a time but more to experiment with many different combinations of botanicals and make enough for about a bottle at a time, at the highest quality that I could.
in order to do this, I followed the methodology outlined in Odin's Easy Gin post. (Full credit to Odin)
I start by diluting 450ml of 95% neutral with 550ml of water to give me close to 1ltr at 43%abv. I add my selection of botanicals to this and run straight through my small home made 2.5ltr pot still. (haven't tried the two week maceration thing yet probably because I haven't got the patience!!)
I have found, contrary to the instructions, that I can sometimes collect a bit more than the recommended amount and on average, usually end up with about 430-440ml. The big difference from your results is that it is nearly always at 77-78%abv. I usually then dilute back to about 43%abv which is quite handy, as it gives me a full 70cl bottle plus some for 'testing' purposes!
Using this method has provided me with some not unpleasant gin which the average gin drinker would stuggle to identify as 'homebrewed'.
If my maths is correct, my yeild is about 76-77%.
So, the differences between what we are doing:-
I start with 1ltr at 43% (450ml spirit) - you start with 1200ml at 30% (360ml spirit)
I do not run anywhere near 500w - I give it the full monty 1500w for a couple of minutes just to speed heat up and then usually start collection at about 200-250w max, sometimes increasing slightly about halfway through, trying to keep the output at a steady fast drip. My run time is usually between 3/4hr & 1hr. I'm not sure what difference a slow collection rate makes, but my logic suggests that it should at least give more flavour from the botanicals, being in the boiling liquid longer. Also, maybe running a lot faster with more power pushes more water over in the vapour. (just a guess on my part!)
I have never bothered collecting past 450ml and never worried about what is left in the pot at the end, but then I am not having to buy the neutral to start with! The mantra I read quite a few times during my early research - You get what you get!!
I appreciate that none of this has really answered your questions but it might give you some ideas of what to try and see if it makes a difference.

Will

[stillgeoff]

Thanks very much for your replies.

I really appreciate the detail that you've given Will and it sounds like my yield is somewhat down on what it should be. I'll do a bit of experimenting with different setups including leaving the botanicals in the charge and will see if that helps!

[stillgeoff]

In case people were interested in this topic, I thought I'd post some progress...

I ran the same setup as described in my original post but I've taken more measurements along the way to see where I'm losing the ethanol. Essentially, there was a small amount left in the pot and also lost in cuts but there is still a large discrepancy between the amount of ethanol that goes into the pot and amount coming out. My final product had a 60% efficiency based on the ethanol that went in.

The losses are:
6% ethanol remaining in the pot
3% lost in cuts
31% other losses between the pot at distilate

This 31% discrepency equates to 112mL of ethanol and I'm at a loss as to where this is going. My only theories are:
- The juniper in the vapour basket increased in mass by 35g so depending on the ABV of the moisture it absorbed, this may account for a portion of it
- Due to the large range in ABV that I'm measuring, I'm using a refractometer. I measured the ABV of the liquid remaining in the pot at 3% and it's crossed my mind that if the accuracy of the refractometer at low ABVs is poor then this would affect the result significantly. This wouldn't help the yield but would explain where the losses are
- I don't know how or where but there could be a vapour loss somewhere along the line. I've seen no evidence of steam though.

If anyone has any more thoughts, please let me know!

[Will Stilltry]

Hi Stillgeoff

As stated in my previous post, I am in no way, shape or form, qualified to offer advice but can only compare my (relatively) successful results with yours. I have used the 'Odin's Easy Gin' methodology more than a dozen times now, as it is perfect for producing a single bottle at a time, and allows me to experiment with different botanicals which I usually dump straight in my small pot still immediately prior to running. I have also experimented by placing everything in a small muslin bag suspended in the vapour path, just the citrus peels in the vapour path and in one case, I even tried chunks of apple and pear suspended in the vapour. As NZChris pointed out with his method, I never lose any of the original alcohol by having to strain out botanicals prior to distillation.
I do not have a thermometer on this particular still, therefore do not run it by temperatures. Being a complete novice, I stuck rigidly to the instructions on my first few attempts, discarding the first 10ml and then collecting exactly 400ml, but then found on some combinations of ingredients, the initial 10ml and a small amount of distillate collected after the 400ml mark was not unpleasant or overpowering, so I included it.
Looking back on all my records now, which are probably not quite as accurate or meticulous as yours but fairly consistent, as I posted previously, I nearly always ended up with 430-440ml at an average of 77-78%ABV which, when proofed down, gave me a full bottle plus a small amount for instant gratification!
I previously calculated that my yield was around 76% but forgot to allow for the fact that the neutral I started with was 95% and not 100% so therefore it is nearer to 79%. If you achieved anywhere near this, (and my maths is any good!!) you would be getting over 275ml instead of 218ml.

Long before I launched into my own 'homebrewing', I attended a couple of gin making 'experiences' at two different craft distilleries and, although I did not appreciate the significance at the time, looking back now they both adopted exactly this same procedure. We were allocated our own mini pot still pre- charged with 1ltr of alcohol, into which we dumped our choice of botanicals and collected approx 400ml of distillate. This was proofed down to give us a full bottle of our own gin to take away. Even though the mini stills were very different, one being a glass flask with a Liebig condenser and the other, a small alembic style still with worm, the results were consistent and identical to what I get now.

My suggestion would be to try following this same procedure exactly, using 1ltr at 43% and see what your results are. If it differs wildly from the results that I, and probably many others have found, it has got to be a problem with your still or perhaps the way you run it. Although you said that your hotplate is 500w, you haven't said what power you run it at. Again, as I said in my previous post, my collection rate is a steady fast drip, usually taking about 3/4hr to 1hr at 250w max.
For the sake of experimentation and to satisfy my own curiosity, I would try running your parameters i.e 1200ml @30% and see what my results are compared to yours but unfortunately, I am clean out of neutral, so my next chemistry practical will be taken up making more of that!!!

Will

[NZChris]

I don't trust my cheap refractometer much over 40%. By 60% it's way out.

Try using a hydrometer to measure the abvs, then calculate the volumes of ethanol in your charge, fractions and backset. Always temperature correct the readings.