first distillation from fresh sugarcane juice (cachaça and rhum agricole)

Anything to do with rum

Moderator: Site Moderator

Post Reply
cachaça
Novice
Posts: 5
Joined: Thu Mar 21, 2019 3:05 pm

first distillation from fresh sugarcane juice (cachaça and rhum agricole)

Post by cachaça »

Hi, this is the story of my last experiment, attempting to make something between rhum agricole and cachaça. I hope my english is not too difficult to read, in that case please excuse me.

"The sugarcane adventure"
Last october during a week-end trip a few hours away from where I live, we stopped by a sugarcane farm and bought about 60 liters of juice as they were pressing at this moment. A few minutes (!) away from the farm the fermentation had already started and we had to make a small hole in the lid for it not to explode inside the car (we did not really planned this whole sugarcane adventure...). We were thinking about letting it ferment spontaneously with wild yeast but we never thought it would be SO spontaneous. Clearly, the press was not a clean one, and even if we tried to filter the juice the best we could it still carried wooden residues, etc.

"A so-so fermentation"
Back home it fermented at a not suited temperature, around 15-20°C (I live in the Andes in a rather "cold" region), and during a long time (3 months...) as we were too busy to go on with the experiment. I have read that fermentation in rhum agricole rumeries takes only a few days and from a visit in Brasil I know that it is the same for cachaça and that it ferments at about 35°C... From what I have seen in a craft cachaça production farm (a clean one!) it seems common to reduce initial gravity to about 15BRIX (1060) and I have read that for rhum agricole it is diluted as well from about 1075 (average fresh juice gravity) to 1045-1050 with dunder and water. I guess they do it to be in a range where interesting yeast works better. Anyway I did not do it, as I said the experiment was not really planned... However, the smell was great, reminding (obviously) the sugarcane "beer" people drink here, "guarapo", but we did not taste it.

"Run it anyway"
Months after, I finally tried and distill it, but I realized the smell had turned very acidic, reminding more of between guarapo and a strong chicha (the other traditionnal drink, made with fermented corn), which is ok for these kind of drinks but could be a problem for making rum... I had about 60l of usable wash (leaving inside the yeast trub) at aproximately 8%abv. I say aproximately because I realized my densimeter had a crack so the measurements are not reliable. Final gravity (measured with a new densimeter) was 1015, which was not as low as expected as I read it should fall to about 995.
Having no experience with sour/acidic mashes I decided to have a try with stripping runs in my 20l pot still. I tasted the first run at the very end of it and the taste was acidic, but as I read somewhere that this taste may come only in the tails I decided to try a second run and pay more attention. I got the confirmation that all the distillate does not taste acidic. So I carried on with the third stripping run.
The second run was a bit shorter as we ran out of gas for cooking and my girlfriend stated interestingly that eating was more important than distilling vinegar...
I got 10l at 40%abv from these 3 runs. I noticed something I don't remember I had seen before: a blue coloration on the border of the filter paper I used to collect the distillate. This happened as well afterwards during spirit run. I don't know if this is specific to sugarcane juice wash or if it is a common thing.

Spirit run
I diluted the distillate to 14l at 28%abv. Runned the slowest I could until well inside the hearts, and then finishing the hearts slow again while getting into the tails.
Foreshots and heads came out like usually, very acetone and solvent like. I collected 1,4l of them. The last 150ml of them seemed to have a nicer smell full of flavour: I will wait for it to develop the next 24-48h and will see if I keep it.
I then collected 4,2l of hearts that remember me my panela version of the famous buccaneer bob's rum (a great recipe with great ratios and tips), without finding any acidic taste or smell!! My girlfriend said at one point she felt "somehow the complexity of vinegar without the acidic part" which I did not agree at this point, but at the very end the smell changed actually toward vinegar and the taste stopped being interesting and started being like dirty water or something like that. I am quite bad at describing it, but I know I didn't like it and I stopped the run. Last 190ml came out at 27%abv.

Conclusion
The great point of all this is that I had no issue with the acidity I was afraid of, and this batch is very likely to turn into a good rum! It would have been a shame to throw the whole wash without giving it a try as I was thinking at the beginning!
Improvements I am thinking about: 1/ the day I buy the juice, prepare a yeast starter (try with inexpensive baker yeast) and nutrients (inexpensive yeast trub saved from a previous batch) and throw it immediately into the fresh pressed juice, 2/ dilute with water as soon as possible (back home) to get rapidly to the 1045-1060 range (if not already reached...), 3/ prepare the fermenter lid and put an airlock on it to prevent any vinegar fly or so to mess with the wash !!
I would be happy to read your comments and feelings about this first experiment, and of course very happy to get any advice for the next try.
Samyguy
Bootlegger
Posts: 130
Joined: Tue Nov 28, 2017 5:40 pm

Re: first distillation from fresh sugarcane juice (cachaça and rhum agricole)

Post by Samyguy »

Great story,an Adventure,
User avatar
NZChris
Master of Distillation
Posts: 13731
Joined: Tue Apr 23, 2013 2:42 am
Location: New Zealand

Re: first distillation from fresh sugarcane juice (cachaça and rhum agricole)

Post by NZChris »

I think your story demonstrates how lackadaisically you can treat sugar cane juice and still end up with a decent Cachaça :D I wonder how good it would have turned out if you did everything 'correctly'? It would have been different, but there is also a chance that it might not have turned out as good.

I wish I had your access to freshly pressed juice. You are very lucky. Make use of it.

Cheers
Chris
User avatar
pope
Distiller
Posts: 1346
Joined: Thu Feb 02, 2012 3:56 pm
Location: Tinseltown

Re: first distillation from fresh sugarcane juice (cachaça and rhum agricole)

Post by pope »

Sounds like the early days for me! A little shoot from the hip attitude. I did some cider batches that way for a few years in the fall.

An acidic wash could have stripped oxides out of your copper (?) still which renders bluish green to blue depending on the oxide. Also acidic washes tend to yield more flavor (good or bad). Sounds like all the happy accidents left you with something good! Maybe just let it go with wild yeast next time but give it a little nutrient and get it heated up more so it’s closer to 25-28c. Should help it finish dry.
"A little learning is a dang'rous thing; Drink deep, or taste not the Pierian spring: There shallow draughts intoxicate the brain, And drinking largely sobers us again." - Alexander Pope
User avatar
NZChris
Master of Distillation
Posts: 13731
Joined: Tue Apr 23, 2013 2:42 am
Location: New Zealand

Re: first distillation from fresh sugarcane juice (cachaça and rhum agricole)

Post by NZChris »

pope wrote: Fri Jan 17, 2020 9:30 pm Should help it finish dry.
It probably did finish dry and below 1.000, but it wasn't run then. Acetic acid has a higher SG than both alcohol and water.
cachaça
Novice
Posts: 5
Joined: Thu Mar 21, 2019 3:05 pm

Re: first distillation from fresh sugarcane juice (cachaça and rhum agricole)

Post by cachaça »

Thank you all for your comments!
pope wrote: Fri Jan 17, 2020 9:30 pm Maybe just let it go with wild yeast next time but give it a little nutrient and get it heated up more so it’s closer to 25-28c.
This is an interesting idea, thank you. It will be easier to carry nutrients in the car than having a starter ready for the right moment without knowing if I am going to find a sugarcane press operating during the trip!
pope wrote: Fri Jan 17, 2020 9:30 pm An acidic wash could have stripped oxides out of your copper (?) still which renders bluish green to blue depending on the oxide.
Yes, copper: 2" diameter with 50cm high column, and a 60cm liebig condenser. Interesting explanation, thank you.
NZChris wrote: Fri Jan 17, 2020 8:56 pm I wish I had your access to freshly pressed juice. You are very lucky. Make use of it.
I want to! Problem is finding time for it. I will make you know how it goes in the next tries.
NZChris wrote: Fri Jan 17, 2020 9:40 pm
pope wrote: Fri Jan 17, 2020 9:30 pm Should help it finish dry.
It probably did finish dry and below 1.000, but it wasn't run then. Acetic acid has a higher SG than both alcohol and water.
You mean that after finishing the alcoholic fermentation at a low gravity, the transformation of alcohol into acetic acid made the gravity go up again? Is that really possible once the liquid is "light" for it to go "heavier". My intuition doesn't want to believe this... I would say that even if acetic acid is lighter than alcohol in theory, the transformation from alcohol into it in the wash should consume other materials or reorganize compounds in the wash and I don't think this wash can get heavier... I am not sure I am clear...
If someone knows about microbiology or chemistry and can help me understand, you are welcome.
User avatar
pope
Distiller
Posts: 1346
Joined: Thu Feb 02, 2012 3:56 pm
Location: Tinseltown

Re: first distillation from fresh sugarcane juice (cachaça and rhum agricole)

Post by pope »

Yea that was news to me, but I’m not surprised alcohol converting to acetic acid can increase density. But you were able to remove the vinegar notes from the final spirit? If it all esterifies the acetic acid becomes ethyl acetate which should theoretically be easy to separate but I’m not sure how bad it smears, if you have larger concentrations maybe it’s a tougher issue to address.
"A little learning is a dang'rous thing; Drink deep, or taste not the Pierian spring: There shallow draughts intoxicate the brain, And drinking largely sobers us again." - Alexander Pope
cachaça
Novice
Posts: 5
Joined: Thu Mar 21, 2019 3:05 pm

Re: first distillation from fresh sugarcane juice (cachaça and rhum agricole)

Post by cachaça »

pope wrote: Sun Jan 19, 2020 4:41 pm But you were able to remove the vinegar notes from the final spirit?
Yes, absolutely!
pope wrote: Sun Jan 19, 2020 4:41 pm If it all esterifies the acetic acid becomes ethyl acetate which should theoretically be easy to separate
Why would it be easy ? According to Wikipedia ethyl acetate has an ebullition point of 77,1°C while alcohol comes out at 78°C if I am right. Is 1°C enough to be sure it is easily separated during a slow distillation? ...
pope wrote: Sun Jan 19, 2020 4:41 pm the acetic acid becomes ethyl acetate [...] but I’m not sure how bad it smears, if you have larger concentrations maybe it’s a tougher issue to address.
I did not notice anything very uncommon in the result. According to Wikipedia again it is an ester with a "specific fruity smell" and low toxicity that can be found in wine and rum. The english page of wikipedia speaks about "pear drops". Sounds ok to have it inside but again with my little experience I didn't notice anything weird.
User avatar
NZChris
Master of Distillation
Posts: 13731
Joined: Tue Apr 23, 2013 2:42 am
Location: New Zealand

Re: first distillation from fresh sugarcane juice (cachaça and rhum agricole)

Post by NZChris »

You don't have to eliminate ethyl acetate to make a nice rum. It's a desirable flavor component of many drinks, but like salt in your dinner, too much or too little can make or break it.
Post Reply