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“Confused about my mistake: Low ABV rum strip”
Ok I’m stripping a 5 gallon batch of rum wash, I’ve collected only 1.5 quarts and already coming off the spout ABV is down to 20%. The whole 1.5 qt = 30%.Recipe: 1 gal Tribute brand equine blackstrap molasses specs TSI 37% dry matter 71% moisture 29% Brix 79.5% (label below).2 lbs turbinado2 gallons wonderful smelling dunder that had sat in the yard in a cloth covered bucket for 9 months. Grew a pellicle of green mold but I was able to lift it off the top like a sheet of fuzzy leather. Still smelled great, like roasted orange peel.Water to make 6 gal (about 1-2 quarts left in bucket after pouring 5 gal into still – see evaporation question below).Vitamin B, DAP, bakers yeast as usualFermented in a room heated to 90F cuz bakers yeast.Airlock bubbled as expected for 2 weeks but the bucket sat for a few months after that and at one point I discovered the airlock had run dry.Taste of wash is sour and smell is smoky like hickory smoked ribs. Tastes pretty much what previous washes were like.Did not measure OG cuz I only had a refractometer and my rum washes always erroneously measure off the scale. Next time I’ll use a hydrometer to measure OG/FG.So I either did not get enough sugar in it or is it possible the alcohol evaporated through the open airlock???Stripped distillate has a bit of a plastic burnt smell, not at all like previous successful batches where the recipe was the same but molasses was food grade blackstrap. I don’t expect the strip to smell yummy, but this is not a smell I have encountered before.I still have 3 gal of the molasses. Add more sugar and try again or donate to an equestrian and buy new food grade?Use the dunder in a new batch or chuck it?Include the funny smelling strip in a new strip?F F F!!!!
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18 Replies
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Letting the airlock evaporate dry for months is where I would put the blame for the low yield.Yeast autolysis can smell like burned rubber and may explain the flavor issue.There is probably nothing wrong with your recipe and ingredients. I’ve used decade old molasses to make some fine tasting rum.I haven’t used a calculator to diagnose your recipe. I ain’t a maths teacher and I expect everyone to do their own maths and check their own calculations, like I have to do tomorrow because I got unexpected results today
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fermentables for the rum recipe i use, for 25L is roughly ….3L (3/4 gallon) of food grade molasses (55% sugar)3kg (6.5lbs) raw sugarso compared to your ingredients, that might be the answer to your low ABV.
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A gallon of Molly at that very low 37% sugar is about 1.8kg of sugar max. Plus the 0.9kg of the other stuff is 2.7kg. I usually have about 6.25kg of sugar from molasses in a wash twice that size and get about 14L at 28%. Translated into American, I would expect about 6.5 quarts of low wines at 28% from your recipe. So it’s not good, for sure. That would be a lot of evaporation. I’ve never considered it before. I’m sure if you do it again but run it after just two weeks it should be fine.There is an infection I believe that eats alcohol. That might be the culprit.I can’t sing, but I sing.
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Thanks y’all!Can someone please explain TSI to me? If a gallon of molasses weighs 6 kilos or so then how much fermentable sugar is there at 37% TSI?Last night, muttering under my breath like in an old Popeye cartoon, I mixed up a new ferment with the same recipe and 4 lbs sugar instead of 2. Pitched fleischmann’s at 113F, left it on the back porch as we are upwards of 90 degrees for a week now. I did use the same amount of fresh dunder from the failed batch and set the rest out on a cloth covered bucket.Once it was all mixed up I pulled out my hydrometer which slipped out of my hands and broke. End of a perfect day…
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Thanks again to you Kiwis!NZChris, the plastic smell is a bit subsided in the small bit I collected. Will that carry over on the spirit run? I have a second bucket to strip LOL. If I manage to salvage this project I’ll be adding maybe 3L of 25-30% low wines from the failed batch to many more liters of the next two hopefully successful 24L batches. No prob right?JustinNZ, when you use 28% low wines as an example is that because you strip that low? Or because I ended up close to there?
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Unless there is a serious fault coming over, I don’t take much notice of the smell of the low wines.When I have had a serious issue, I’ve kept it separate rather than trying to dilute it or use the backset. More by good fortune than design, I have acquired a set of stills that lets me do spirit runs in the next size down boiler. That enables me to age my cockups separately on the offchance that they might be useful for blending in a few years time.With a new batch of molasses, I often start with a single charge worth of wash to make the dunder and yeast bed for a triple charge second generation. The amount of alcohol produced lets me reverse calculate how much fermentable sugar there is in that batch of molasses.
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My recommended goto .wiki/index.ph … ion_Theory
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Yes, Captain, that’s typically what i get from a stripping run. It’s the abv that fills my stripping collection pot (no, that’s not a side-hussle!). Molasses is funny stuff. Down here you can get Bundy 10L cubes that weigh 14kg. My stuff is real blackstrap that horses like, weighs 25kg and doesn’t quite fill a 20K pail. So depending on various things I expect a molasses to be about 1.25 to 1.4 times the volume in weight. The sugar content varies a lot, like I mentioned earlier. A while ago I got a lazy infection that gobbled-up a fair bit of the alcohol in my wash. Smelled and tasted interesting though – but it’s still aging so I don’t know if it’s a winner or not. Good luck out there!I can’t sing, but I sing.
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Oh yeah, you asked another question. That 37% thing is the percentage of the weight or volume that’s sugar. Can’t remember which one was on your label. Anyway, if I bought 10 lbs of it, I’d expect 3.7 lbs of sugar. 37% of something means 0.37 x the something. By weight is easy, I think. That’s why most recipes use weight. Some use Volume though, like SBB’s rum. I adapted it from 8L to 8 x 1.4 = 11.2kg of molasses – max. Which at 50% sugar by weight is about 5.6kg of sugar in an approx 28L wash. Probably a bit less sugar.My brain just exploded. I hope I’m not screwing this up. I’m gonna look at my molasses label now. Yeah, mine is 510 grams of soluble sugar per kg. 51% sugar. Yeehah.I can’t sing, but I sing.
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Interesting, Ive never noticed that before. That extra weight might be the extra flavor hidden in there.
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25 divided by 1.4 equals approx. 18 Liters. I do not see the difference.
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I started posting earlier and got as far as converting all the units to metric . Sure we use weight for most recipe’s , kg or pounds of sugar or grains , but when it comes to Molasses , it’s easier to mention volume . IE , “please Sir can you fill my 20 litre pale “ Molasses typically has a Specific gravity of 1.38 , so calling it 1.4 is close enough .Your 1 USgal ( 3.785 litres ) will weigh 5.299kg .However , % of sugar etc is also based on weight . Therefore , if it has 37% sugar , that means that it has the equivalent amount of sugar of 1.96kg .Plugging the Molasses into a wash calculator ( for 6USgal …22.7l ) gives a wash abv of 5.1% Adding the 0.91kg of Turbinardo gives a total sugar of 2.87kg . Plugging that into a calculator gives a wash abv of 7.4% If you only got to distill 5US gal (18.925 litres) there is still a potential 1.4litres @ 100% abv .You say you only managed about 1.42 litres and that was only 30% abv .I would agree that you came up way short .I don’t think your recipe or Molasses is bad . I do think you are using too much dunder .Cut that back to about 1/10 of your wash volume .I have never sealed my fermenters with more than a cover to keep the insects out and often leave them for a month or two before distilling . I have never had Alcohol loss.I certainly don’t believe you lost 2/3 of your potential Alc through a dry airlock . .I’m calling incomplete fermentation or possibly a leaking still as more probable causesMy recommended goto .wiki/index.ph … ion_Theory
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I concur with the above, too much dunder in the ferment. 2gal of dunder in a 6gal ferment (33% of the liquid volume) is going to get you a really low starting pH.This likely resulted in the yeast struggling from the start, then stalling, so you just didn’t get a complete ferment.Make Booze, not War!
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i don’t think that it’s too much dunder on a first ferment, as opposed to a 2nd generation, when that much dunder can cause you real PH problems.the tried & proven rum recipe i use calls for 10L of dunder (2.6 gallon) and this goes off pretty well on a first ferment only.about 10 L of dunder brings my tap water from PH 8 down to 5.it doesn’t work out as well if you’re using the trub for a 2nd generation, where i usually use only 4 – 5 L (1 gallon) of dunder.the PH of everything should be checked before adding the dunder.(and after obv)there is no mention of the original PH, or any subsequent readings by the OP.
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Yeah, good point! Can’t argue with that. I’ve always assumed there was some variation between weights per litre because of sugar content (and maybe other content) and that my 20L pails were oversized. Damn – now I gotta go and measure my pails.I can’t sing, but I sing.
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I am very grateful for the attention and advice here!My recipe was basically Pugi Rum. He uses 1.5g dunder in a 5 gallon batch so 30%! I have read that up to 40% can be ok. I’m at 30% like Pugi. Last year’s batches were just that and worked splendidly! Granted – the dunder for this batch sat out all winter so maybe was more acidic? I did boil it as he does for the yeast bomb so killed anything still alive. Scooped the dead rats out, etc.No leaky still – digiboil with alembic dome and pretty new silicone gasket. No smells or visible leakage/condensation. It’s been stripping malt whiskey and UJSSM just fine! (5 gal of each ready for spirit runs Getting about 6 L at 30% from each 23 L batch.Looked back at my notes – ferment started May 25 and stripped a few days ago. Dry airlock discovered late June? A week or two seems not long enough for alcohol evaporation. Alcohol eating bacteria? Last year I had a batch sit 2 months no problem but airlock did not dry out. This ferment was sour and not sweet at all.I worked the numbers now that I understand better.; I weighed the horsey molasses! Sorry for the freedom units.1 gal = 11.5lb and at 37% TSI that’s 4.255 lb sugarAdded 2lb turbinado for total of 6.255lb sugar in a 5 gal batch.According to calculators I should have expected 8.3% (2.84kg sugar in 19 liters).Is all that sugar fermentable?The second bucket did better, collected about 2 liters at 30% and no plastic smell. But I was expecting 6-7 L.So anyway for this time I did 4 lbs sugar instead so I should have 3.74kG sugar between the molasses and turbinado. Mixed to 5 gallons and the hydrometer was off the scale so I added another gallon water and hydrometer reads 1.42! The molasses is THICK. Second bucket same recipe hydro reads 1.36. Sugar calculator says for this 22.71 liter batch with 3.74kg sugar my potential is 9.7%.Ph is about 4.I dunno – a fluke I hope.Anyhoo this time I’ll strip no more than a week after bubbles stop. I’ll track ph and SG. If it doesn’t work I’ll assume it’s the Tribute Molasses and go back to golden barrel. Dammit it’s now the same price as the Tribute was [face palm].
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SOLVEDPH was more like 3.4 – I added too much dunder that had sat in the yard for A year and got too acidic. I know this cuz the batch I just started would not start after 4 days. I put a good cup of Potassium Hydroxide drain cleaner in each 6 gal bucket, brought the ph up to about 4.8 and one of them started bubbling within minutes LESSON LEARNED: TRACK PH WHEN USING DUNDER – ESPECIALLY OLD DUNDER! Add enough to get your wash to 4.5 – 5.0.Gonna be the best damn rum ever!
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I thought as much, seemed too obvious not to be a pH based problem. Anyway I’m glad to hear you got to the bottom of it and have been able to remedy the pH this time. Potassium Hydroxide sounds a bit extreme though, maybe use a slightly less caustic base as a pH buffer going forward?Yes it’s considered “Food safe” in industry but not to be messed with as it’s a really strong base. Will de-fat your skin in seconds.Make Booze, not War!
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