Question on a rum wash

erbachem · Post by **erbachem** » Sun Mar 04, 2007 11:59 am

I have my first rum wash sitting in the corner at the moment doing nothing much. Looking for a bit of advice before I make the next move.

Preliminaries
- 50L wash
- 16kg Molasses (feedstock grade)
- 1kg Dextrose I had lying around
- Lalvin ec1118 yeast

The wash has come to a standstill with a gravity reading of 1040 after three weeks. I was half expecting the gravity to finish reasonably high given the amount of 'impurities' present in molasses but this is a lot higher than I expected. The O.G suggested a potential of 16%. I have the exact reading at home and will publish it if this is useful information.

Has my wash really finished or has it stalled? One thing I realise I forgot to do was to acidify the wash with some citric acid. I know for a fact that the temp has never gone over 20 degrees celsius so the yeast isn't dead through heat.

My options here are to put it through the pot still as is or try and kick start it with some more yeast with a little citric acid this time.

Any recommendations from the old hands out there?

Post by **Tater** » Sun Mar 04, 2007 12:53 pm

Run it to see is what Id do.

stoker · Post by **stoker** » Sun Mar 04, 2007 1:20 pm

16% is enough to run. your yeast may have run out of sugar, or died because of the abv.

Post by **Husker** » Sun Mar 04, 2007 2:00 pm

You put too much molasses into that mash. Molasses can be great stuff, but when it is too strong, it almost acts like a toxin for the yeast. 16kg is like 3.5 to 4 gasllons. That much in a 12 gallon wash is just too much IMHO.

You might try taking a gallon of your wash, cutting it with 3 Qt of water, and use that as a yeast starter. Use 2-4 satchets of EC1118. Then cut the main batch with about another 4 gallons of water. Let this new starter work for a day (or until it is REALLY active), then dump that starter into your main mix.

It should drop to 1010 (or lower). NOTE if you keep your temp at 20°C, then the yeast will take much longer to work. However, right now, it sounds stuck.

HOWEVER, before trying any of the above, taste the mash. If it is not sweet, then simply run it, and "assume" that there was something in the molasses which is chaning the S.G. enough to throw off your readings.

PS, what was your starting S.G. ?

H.

PPS, you could also run it, and keep the backset (if there is still sugar in it), then use this in your next "run", so that the molasses and the sugar still in the wash will be used by the next batch of yeast.

erbachem · Post by **erbachem** » Sun Mar 04, 2007 6:46 pm

Thanks for your advice. Definitely gives me some next steps to consider. I'll check the wash when I get home and make up my mind from there on next steps. I'll post the O.G. as well once I am in front of my notes.

At least I have a reasonable idea of what went wrong now. Just need to figure out the best way to fix it.

muckanic · Post by **muckanic** » Sun Mar 04, 2007 8:23 pm

Doesn't sound to me like either an excess gravity or an acidity problem. I would be inclined to kick-start the ferment by pouring it back and forth between fermenters. An open ferment technique might also allow it to vent off any sulphur that is inhibiting things, and there should be enough alcohol already in there to prevent any bugs taking hold. Maybe add some inert particulate matter like bran for good measure.

erbachem · Post by **erbachem** » Mon Mar 05, 2007 11:37 am

Well, I've checked my notes and O.G. was 1.106. Since it is now sitting at around 1.040 I'm expecting about 10% alcohol.

I tasted the wash and sweetness was not the first or even second thought I had. Bloody horrible in a strong molassessy sort of way would be the best description but with no real sweetness to speak of.

My current thinking is that the feedstock molassess I have used is relatively low in convertible sugars. I'm going to test this by draining off 4L and adding 300g of sugar. If this kick starts the sample in to life I'll add 5kg of sugar to the main wash and let it come back down to the 1.040 mark again to give me an end result of around 15%

If the theory doesn't hold, I'll start thinking about plan B. If anyone is interested, I'll keep you updated on progress.

Uncle Remus · Post by **Uncle Remus** » Tue Mar 06, 2007 7:38 am

I made some rum with too much molasses before too. I had to distill it 3 times in the pot still before it was drinkable. It simply had too much body. BTW a half a cup or so of lemon juice helps with fermentation.

erbachem · Post by **erbachem** » Wed Mar 21, 2007 6:37 pm

Just an update on the Rum wash for anyone that is interested. My first action was to do what has served me well in the past when facing spirit / beer problems which was nothing.

After a few weeks of nothing I was able to confirm beyond doubt that nothing was happening so it was obviously time to move to plan B which was add some more dextrose. To start with, I added a mere 300g to the wash. Hey presto, next day the wash is bubbling along quite happily again. I'll be adding an extra 3-odd kilo's of dextrose to the mix which, assuming that it all gets fermented out, should bring the wash up to around the 15% mark. All going well I'll be distilling in a couple of weeks.

erbachem · Post by **erbachem** » Fri Apr 27, 2007 1:10 pm

Well, so much for hopefully bottling in a few weeks. The thing just refuses to stop bubbling. At this rate I'll be lucky to run in through in the next month.

CoopsOz · Post by **CoopsOz** » Fri Apr 27, 2007 2:16 pm

erbachem wrote:Well, so much for hopefully bottling in a few weeks. The thing just refuses to stop bubbling. At this rate I'll be lucky to run in through in the next month.

You just can't win, at least it's better than being stuck!

junkyard dawg · Post by **junkyard dawg** » Fri Apr 27, 2007 9:19 pm

adding some amylase might help you too. There are lots of unfermentables in mollasses that amylase can break down into fermentable sugars. I'm guessing that the readily fermentable sugar has been used, and the high sg numbers represent the unfermentables left in the wash. If it were mine, I'd add amylase if it were handy, otherwise Id run it and use much of the backset in the next batch, and be sure to use an enzyme at that time, to maximize the fermentable sugar in the wash.

erbachem · Post by **erbachem** » Tue Jul 17, 2007 4:56 pm

Well, I finally managed to distil my rum out a couple of weeks ago. For a first time try I am pretty impressed with the turnout. The end product is quite sweet for a rum and has a molasses flavour that overpowers pretty much everything else. That said, however, it still tastes more like rum than the vodka + sweetener versions I have done in the past. One of the first comments from tasters straight from the still is that the rum high notes were there but it was missing the body. I'm experimenting with oak and dilution with high quality vodka to try and reign in the high notes and add body at the same time.

Given that the overall cost is reduced by about two-thirds in the process as well as the fact that it is not hugely different from running a sugar wash and I am in no hurry to go back to the reflux method for future rums.

I have added sugar to the backset and have that on the bubble ready for my second run. I tried keeping a bottle of sediment from the first run in the fridge while I was distilling to use as a starter for the second but it didn't seem to have much effect. Adding some EC11138 kicked things off nicely.

Post by **Husker** » Tue Jul 17, 2007 6:16 pm

erbachem wrote:One of the first comments from tasters straight from the still is that the rum high notes were there but it was missing the body.

That lacking "body" comes from multiple generations, and putting a percentage of your dunder (left over in the still) back into your next runs.

That is the way you get a "full bodied" rum. You are certainly on the right track. Also, the flavor structure will change a little (and possibly a lot) if you allow your product to "air out" overnight. It may remove some of that vodka "high notes" you describe.

I know that one of the best ways to rid a whiskey of the "moonshine-ness" is to air it out (aging will also do this, but slower). Rum is similar.

H.

junkyard dawg · Post by **junkyard dawg** » Tue Jul 17, 2007 6:42 pm

That lacking "body" comes from multiple generations, and putting a percentage of your dunder (left over in the still) back into your next runs.

yep

Still more · Post by **Still more** » Thu Jul 19, 2007 5:13 am

What percent of dunder are you adding to the next wash for rum? Same as UJSM a 1/3 or so?