RUM Specific Gravity

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sergiolis
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RUM Specific Gravity

Post by sergiolis »

I'm just in my second generation of molasses rum, so just trying to get something decent.
I decided to go for Hook Rum but my proportion of molasses is much more higher than the recipe, mainly because here raw sugar is really expensive and in this case I paid even less for molasses than white sugar.
As HookLine points out trying to measure the specific gravity with a hydrometer is not very useful. However, I'm a bit confused because some of you talk about SG and for me it didn't work. So after the stripping run I checked the ABV of the low wines and then I could work out the SG of my worts.
Do you think this method is close (or acceptable) to the usual method using a hydrometer?
Thanks in advance
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Oldvine Zin
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Re: RUM Specific Gravity

Post by Oldvine Zin »

When I started to do rum washes I picked up a refractometer, works great on sticky sugar - molly goo. Now I use it for all my ferments.

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Re: RUM Specific Gravity

Post by GrassHopper »

Well, that method may work for sure. But, I would rather know prior to distilling that I have something, than to distill and find out there is nothing. Just sayin'
Therefore, a refractometer is a good tool.
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Re: RUM Specific Gravity

Post by Yummyrum »

It is pretty much a pointless exercise checking SG on a Molasses wash as the hydrometers are way out at the high end for determining AVB of the wash . Last all molasses wash I did the hydrometer was so floating so high that it was past the numbers and I had to estimate it as 1.140 yes folks thats right . And the final gravity FG was 1.050 . Its a pointless exercise but always good to see repeatability .
As far as knowing when the ferment is done , I use my tongue . Still sweet .... not done , dry and bitter ..... done . :D

Ut as far as calculating wash ABV , I recon your method is as good as any . :thumbup: .... sure its finding out after the event but its all good stuff to know

Now all you have to do is drop the sugar alltogether and make some real Rum :ebiggrin:
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Re: RUM Specific Gravity

Post by Bushman »

Oldvine Zin wrote:When I started to do rum washes I picked up a refractometer, works great on sticky sugar - molly goo. Now I use it for all my ferments.

OVZ
+1, some refractometers only measure in brix others have both readings and if your not used to the measurement brix then you can go to the Glossary and look up Brix scale and there is a conversion formula for converting to SG.
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Re: RUM Specific Gravity

Post by sergiolis »

Thanks guys,
I will get some information about refractometers, but I must say I was enjoying a lot estimating the SG or the total amount of fermentable sugar in my molasses without any tool... :D
My first worts are double distilled and resting in oak chips at 60%ABV. This is a new complex world for me...
Surprisingly at present, in its raw form, the flavour is not much different than a panela rum
Really appreciated your comments...
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Re: RUM Specific Gravity

Post by Bushman »

You can find them on Amazon or EBay and they are not that expensive.
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Re: RUM Specific Gravity

Post by muscashine »

Yummyrum wrote:It is pretty much a pointless exercise checking SG on a Molasses wash as the hydrometers are way out at the high end for determining AVB of the wash . Last all molasses wash I did the hydrometer was so floating so high that it was past the numbers and I had to estimate it as 1.140 yes folks thats right . And the final gravity FG was 1.050 . Its a pointless exercise but always good to see repeatability .
As far as knowing when the ferment is done , I use my tongue . Still sweet .... not done , dry and bitter ..... done . :D

Ut as far as calculating wash ABV , I recon your method is as good as any . :thumbup: .... sure its finding out after the event but its all good stuff to know

Now all you have to do is drop the sugar alltogether and make some real Rum :ebiggrin:
I've found the same issue with the hydrometer. My usual rum recipe is 2 pounds of dark brown sugar per gallon of water. The hydrometer helps because it does sink some but it never really gets all the way to the 0% mark like a wine does. I had a stuck ferment this week, but after a couple of days of fiddling with it, I realized my issues and it has taken off again. First time using bread yeast as suggested.
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Re: RUM Specific Gravity

Post by der wo »

muscashine wrote: My usual rum recipe is 2 pounds of dark brown sugar per gallon of water. The hydrometer helps because it does sink some but it never really gets all the way to the 0% mark like a wine does.
Without molasses? And the hydrometer doesn't work? Water and sugar, nothing else? Then no wonder, it doesn't ferment dry, without any nutrients. At least with the information I have it's not a rum specific gravity problem.
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Re: RUM Specific Gravity

Post by Saltbush Bill »

I think if you do a bit of research you might find that refractometers dont give a very accurate measurement on molasses and water either.
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Re: RUM Specific Gravity

Post by jb-texshine »

Sbb,what ratio of molasses to water do you use with stock feed molasses? 1:4 gallons? 1:5?
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Re: RUM Specific Gravity

Post by NZChris »

For rum, I calculate the fermentables and the expected SG drop. Then, if working with the same molasses each time, it soon gets easy to tweak your recipe to allow for your errors in your original estimates.

I've been using a refractometer for over thirty years and I started with rum. They are a very versatile tool once you know how to use them.
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Re: RUM Specific Gravity

Post by Saltbush Bill »

jb-texshine wrote:Sbb,what ratio of molasses to water do you use with stock feed molasses? 1:4 gallons? 1:5?
JB its easier to just give you quantities used than ratios.
8L Stock Feed Molasses
4L Dunder hot from still.
16 L of rainwater from tank
Total 28L
Wash also has contents of one Vit B capsule and a good pinch of Epsom salts.
Lowans Bread yeast.
Yields roughly 9%.
Done many of these washes ....never touched PH and never had one fail.
Have used these same ratios for ferments up to 180L
A finger dipped and sucked will tell you if its done....it should be dry and slightly sour/bitter tasting.
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Re: RUM Specific Gravity

Post by frunobulax »

I found that blackstrap has an average of 45% sugar,(by weight) and weighs about 12 lbs per gallon. So a gallon will have about 5.5 lbs of sugar.
Then I'll formulate my recipe from there. If I remember right, the last one we made was 2 -5 gallon pales (golden barrel) into a 40ish gallon wash.
I also use the sugar calculator on the parent site, and a hydrometer and or refractometer.
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Re: RUM Specific Gravity

Post by thecroweater »

Keep in mind SBB comes from cane country and has access to quality molasses. That means he gets 9% from his molasses with it high content of fermentable sugar. I have tasted the molasses he uses and it tastes something like treacle whereas a lot of the stock feed molasses ( black strap) down here tastes like some weird bitter licorice. They may read a similar brix but in fermentable sugars you might be lucky to yield 3% without the addition of raw sugar (I have even had less than that).
Here's the thing about alcometers/ alcohol hydrometers, due to unfermentables in suspension your SG maybe be out but panic not as so will your FG be likewise out. What this means is the calculations will still give you an exact ABV, a refractometer will at best give you an aproxamation and crap in suspect ion will further convolute the reading
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Re: RUM Specific Gravity

Post by LWTCS »

Betcha goose would just tellya based on taste round about where your yields would be,,if he was from cane country. Betcha he would say that ole boys find it hard to read them little numbers by the light of the moon? Though I certainly don't presume to speak for goose. Nor do I think he would appreciate it.

Problem is that there are other suspended solids within molasses that can distort the Brix.

18 brix is near perfect for Saccharomyces Cerevisiae when using fresh press cane juice as per my dad's retired, sugar chemist, buddy from "Big Sugar".

1 gallon of molasses combined with 3.5 gallons of water will often get you to 15-20 Brix......(notice the range?).

Ever look at the analysis of various grades of molasses? Often all of the constituents listed have a range rather than a specific number. So much so that many of the constituents within each grade appear to be relatively equal in volume when considering the published range from grade to grade. Even the molasses providers do not really know specifically what is fermentable and unfermentable within their own publicized analysis. Ash content seems to be the determining factor more often than not when it comes to judging the grade.
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Re: RUM Specific Gravity

Post by Yummyrum »

Saltbush Bill wrote:I think if you do a bit of research you might find that refractometers dont give a very accurate measurement on molasses and water either.
I agree Salty . Some people have the notion that refractometers have the magical ability to only measure the sugar in what they are measuring .
This is not true . A refractometer relys on light bending ( refracting) due to the thickness ( specific gravity) of the sample it is looking through .
The light doesn't know if its water , sugar syrup , urine , shit .... or all the organic material thats still left in molasses for that matter .All it knows is how thick the stuff is and it bends accordingly .

Strangely , a hydrometer works in a similar way , it just floats or sinks depending on how thick the stuff is its floating in .
Same shit .... different shovel.
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Re: RUM Specific Gravity

Post by muscashine »

der wo wrote:
muscashine wrote: My usual rum recipe is 2 pounds of dark brown sugar per gallon of water. The hydrometer helps because it does sink some but it never really gets all the way to the 0% mark like a wine does.
Without molasses? And the hydrometer doesn't work? Water and sugar, nothing else? Then no wonder, it doesn't ferment dry, without any nutrients. At least with the information I have it's not a rum specific gravity problem.
I think that was my problem! I added yeast nutrient and it worked off. I don't know why I didn't think of it before. My ferment stopped but still tasted sweet. I added the nutrient and it took off again and is down to around 1% potential alcohol, fizzing like crazy.

New problem. I was told (on here) to use bread yeast, that it works better for Rum, so that's what I used. Last few times I used ec-1118 and it's smelled wonderful, like someone baking cookies. The bread yeast has this pungent, sulphur smell to it. It's running me out the house. I'm hoping that smell doesn't carry over into the product, that it's all coming out of the wash.
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Re: RUM Specific Gravity

Post by der wo »

Sulphur smell is related to lack of nutrients. Or lack of easy to consume nutrients. Normally it occurs in the first stage of fermentation and stops smelling later.
Copper helps against sulphur smell.

Adding nutrients later solves the problem only partial. The yeast needs the nutes at the beginning most. But of course be happy that it started again. :thumbup:
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Re: RUM Specific Gravity

Post by Pikey »

muscashine wrote:
der wo wrote:
muscashine wrote: My usual rum recipe is 2 pounds of dark brown sugar per gallon of water. The hydrometer helps because it does sink some but it never really gets all the way to the 0% mark like a wine does.
Without molasses? And the hydrometer doesn't work? Water and sugar, nothing else? Then no wonder, it doesn't ferment dry, without any nutrients. At least with the information I have it's not a rum specific gravity problem.
I think that was my problem! I added yeast nutrient and it worked off. I don't know why I didn't think of it before. My ferment stopped but still tasted sweet. I added the nutrient and it took off again and is down to around 1% potential alcohol, fizzing like crazy.

New problem. I was told (on here) to use bread yeast, that it works better for Rum, so that's what I used. Last few times I used ec-1118 and it's smelled wonderful, like someone baking cookies. The bread yeast has this pungent, sulphur smell to it. It's running me out the house. I'm hoping that smell doesn't carry over into the product, that it's all coming out of the wash.
Is that a US Gallon or Imperial Gallon ?

If US Gallon, that will give you quite a high abv by bread yeast standards and may cause stressing of the ueast and "off flavours" which some mention - whilst ec 1118 will still be well in it's comfort zone and still working at good efficiency.
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Re: RUM Specific Gravity

Post by Danespirit »

+1 Der Wo

Nutrients are important for the yeast to thrive.
They seem especially to love B-vitamins. So usually I add 1 crushed B-vitamin pill to the ferment.
Like stressed yeast, a lack of nutrients produces off flavors.
Furthermore, the ferment will stop prematurely, like yours did.
The surviving yeast will also feed on the dead yeast cells (yes the little devils are cannibalistic).
I use yeast trub as a nutrient for a new ferment, seems it works just fine.
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Re: RUM Specific Gravity

Post by muscashine »

Pikey wrote:
muscashine wrote:
der wo wrote:
muscashine wrote: My usual rum recipe is 2 pounds of dark brown sugar per gallon of water. The hydrometer helps because it does sink some but it never really gets all the way to the 0% mark like a wine does.
Without molasses? And the hydrometer doesn't work? Water and sugar, nothing else? Then no wonder, it doesn't ferment dry, without any nutrients. At least with the information I have it's not a rum specific gravity problem.
I think that was my problem! I added yeast nutrient and it worked off. I don't know why I didn't think of it before. My ferment stopped but still tasted sweet. I added the nutrient and it took off again and is down to around 1% potential alcohol, fizzing like crazy.

New problem. I was told (on here) to use bread yeast, that it works better for Rum, so that's what I used. Last few times I used ec-1118 and it's smelled wonderful, like someone baking cookies. The bread yeast has this pungent, sulphur smell to it. It's running me out the house. I'm hoping that smell doesn't carry over into the product, that it's all coming out of the wash.
Is that a US Gallon or Imperial Gallon ?

If US Gallon, that will give you quite a high abv by bread yeast standards and may cause stressing of the ueast and "off flavours" which some mention - whilst ec 1118 will still be well in it's comfort zone and still working at good efficiency.

AH! That explains a lot. I wondered what it was... because the second batch I started with the same proportions but with nutrient added to start with, also smelled awful. I've never had a problem with the EC1118 or KV1116 working just fine, but there's not a whole lot of the molasses smell carryover from the dark brown sugar. I was hoping for something a bit more flavorful.

I poured out the second batch, the wife couldnt stand the smell in the house. But the first one is done. I'll probably just run it off twice with some of my tails from the last batch of muscadine shine if it sucks on its own, maybe I can get some neutral stuff to make Strawberry Panty Dropper.
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Re: RUM Specific Gravity

Post by Saltbush Bill »

muscashine wrote:but there's not a whole lot of the molasses smell carryover from the dark brown sugar. I was hoping for something a bit more flavorful.
Try using 100% molasses and bakers yeast, no sugar. You will get much more flavour.
Last edited by Saltbush Bill on Wed Mar 15, 2017 1:23 pm, edited 1 time in total.
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Re: RUM Specific Gravity

Post by bentstick »

Easiest all molasses rum I have done and the easiest repeatable is the recpie Salty gave,and no need to fight it try it!
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Re: RUM Specific Gravity

Post by muscashine »

Saltbush Bill wrote:
muscashine wrote:but there's not a whole lot of the molasses smell carryover from the dark brown sugar. I was hoping for something a bit more flavorful.
Try using 100% molasses and bakers yeast, no sugar. You will get much more flavour.
I'll have to try that... as far as the bread yeast smelly rum, it didn't turn out. I ran it off yesterday and a lot of the off flavors came out in the fores and heads, but they stuck with it through the hearts.

I'm thinking of starting a new brand, the Egg Fart Rum Company: Because thats what it smelled and tasted like. It was a completely wasted morning distilling. I tossed it in the yard.
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Re: RUM Specific Gravity

Post by Yummyrum »

muscashine ...
Saltbush Bill wrote: 8L Stock Feed Molasses
4L Dunder hot from still.
16 L of rainwater from tank
Total 28L
Wash also has contents of one Vit B capsule and a good pinch of Epsom salts.
Lowans Bread yeast.
Yields roughly 9%.
Done many of these washes ....never touched PH and never had one fail.
Have used these same ratios for ferments up to 180L
A finger dipped and sucked will tell you if its done....it should be dry and slightly sour/bitter tasting.
This is the go recipe for starters :thumbup:...this guys Rum tastes good
He does some good cuts on it too after running through a 4 plate still
And he has an aging keg :mrgreen:...luck bugger Salty :thumbup:
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Re: RUM Specific Gravity

Post by sergiolis »

I got this molasses from Colombia.
I hope it is similar to the feed stock molasses you can get...
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