Double distillation

[thepopeofantelope]

MileHi posted a how to on rum. I'm confused why the distillate is removed, diluted, and returned to the boiler. What physical/chemical change is occurring with the first run that adds flavor?

You’ll want to run the rum wash through two separate distillations. During the first, you’ll collect the entire distillate without separating the heads, hearts and tails. That will be done during the second round of distillation.

If using a condenser, turn on the water when the boiler reaches 130 °F.

At about 168 °F the still will start producing. Increase the temperature to keep producing distillate.

Stop collecting distillate after it measures less than 20% ABV which you can measure using the hydrometer. Be sure to hold on to the remaining contents of the still as you’ll be adding it back in with your second distillation. This will add to the final flavor of the product. Dilute the first round distillate by 20% with water. Stir the mix thoroughly and add back into the still. Begin your second round of distillation.

[still_stirrin]

The double distillation removes a lot of the water from the product. In addition, it removes a lot of the dissolved solids and allows for separation of congeners, some of which are undesireable in the product.

For a rum, double distilling will remove some of the thicker, oily flavors and allow the more delicate rum (molasses) flavors to stand out.

I advocate double distillations. And when I use “deer lick” molasses as the fermentable materials, I even had to triple distill it to get it drinkable. But, your tastes may vary. And your molasses may be different. Regardless, double distillations with a potstill produces a rum with higher purity yet pronounced molasses based flavor.
ss

[thepopeofantelope]

The instructions state to distill out the alcohol until you hit 20%, dilute the distillate with 20% water and add back into the still with the gunk from the first run. Are the instructions wrong about adding the diluted distillate back to the gunk? I can see that distilling only the distillate will clean it up.

[still_stirrin]

pope,

I think those “instructors” are off the mark...more about selling equipment and less about real experience. You need to pay attention who you listen to.
ss

[raketemensch]

The instructions state to distill out the alcohol until you hit 20%, dilute the distillate with 20% water and add back into the still with the gunk from the first run. Are the instructions wrong about adding the diluted distillate back to the gunk? I can see that distilling only the distillate will clean it up.

You never want to have liquid at more than 40% alcohol in your boiler. Odds are that after your first run you’re averaging closer to 60%.

So, before you fire up your second run you’ll probably have to dilute it with something. Some people use water, some people use wash, some people use straight backset (what’s left in the boiler after you stop at 20%), and for rum lots of people use dunder, which is basically rum backset that’s been allowed to get funky — infections, bacteria, goat heads, etc.

They’re giving you some easy math with that 20%/20% method, but if you want to get good at making this stuff you’ll want to get lots of practice with checking your ABV all the time. I highly recommend picking up a spirit refractometer (they’re $15 on eBay) so that you can check it instantly with ~5 drops of liquid instead of a full alcometer flask or parrot.

[OtisT]

Ya, those instructions are clear as mud, and I don’t think I’d follow them. The way I’m reading it, it’s got major problems. Just my opinion. Maybe they know some stilling voodoo I don’t, which is entirely possible.

For a noob, I would recommend you make a rum first w/o dunder (stuff left in the boiler after your first run) before working with it. That way, when you start using dunder you can understand what it does for your product.

Adding water to what you collect in the first run is a good way to make a smoother drink with less flavor than what you would get w/o adding water. I do it when making neutrals, but not making rum because I like more flavor. It’s not wrong. Just depends on what you are making.

Easy would be to dump your dunder out (or set it aside for later use) then put your low wines back into the boiler w/o water and do your spirit run. That’s just me. (Only dilute if you ABV is above 40%.)

In the future, I highly recommend you try a rum recipe in the HD Tried & True recipe section. Those are proven recipes, explain the process better, and have been vetted by lots of folks for consistent results. You will get better support here if you follow the recipe/process in T&T without deviating.

Good luck. Otis

Edit: . Make sure the wash for your spirit run covers your heat element and that it will remain covered throughout the spirit run. If you don’t have enough volume, you should do another rum ferment, strip it, then add both batches of low wines together for a spirit run.

[Saltbush Bill]

Like some of the stills they make ...not quite up to scratch. Better to use tried and true recipes from the forum.

[thepopeofantelope]

Consensus has it, the instructions are bad. I will do a stripping run and dilute to 40% with backset, then a spirit run.

I brew beer and after the fermentation is complete I lower the temp to 40F to cold crash all the yeast cells and proteins out. I get a very clear product and dense sludge on the bottom. Has anyone cold crashed a rum wash to remove particulate?

[OtisT]

Consensus has it, the instructions are bad. I will do a stripping run and dilute to 40% with backset, then a spirit run.

Pope
Are you running a pot still? If you are, you should consider stripping down further if you are getting Low Wines above 40%. A lot of the good rumminess is in the oils found in tails? IMHO I would recommend stripping until your output is below 10% ABV, maybe even further. You can still add dunder to that. Otis

[thepopeofantelope]

Consensus has it, the instructions are bad. I will do a stripping run and dilute to 40% with backset, then a spirit run.

Pope
Are you running a pot still? If you are, you should consider stripping down further if you are getting Low Wines above 40%. A lot of the good rumminess is in the oils found in tails? IMHO I would recommend stripping until your output is below 10% ABV, maybe even further. You can still add dunder to that. Otis

Running a CCVM 1.2m column with out packing and coil condenser block so all vapor passes to the liebig arm. Thanks for the advice, I will strip to 10% ABV

I've been making excellent gin from ethanol from this rig for two years now. After removing the fore shots when making ethanol and seeing how harsh they are, I was wondering if I should use a packed column to strip them from my rum low wines before the spirit run.

[thepopeofantelope]

I collected the spirit run in 100ml quantities and found it quite easy to make rum cuts. I blended the hearts and have 1.5l or 1.5gal.

Since I only found light molasses and didn't have dunder the rum flavor is weak. It has a sharpness that is not pleasant. I mixed it with Coke and it tastes like a tequila and Coke. Further reading, I find that even white rum is oak aged to smooth it out. I don't want the smoky flavor associated with whiskey from barrel aging in my rum. There are many conflicting instructions on char, toasting, quantity and time in postings on aging across the form.

I have American oak medium toasted cubes. I want to age a pint at a time. Can someone suggest the number of cubes and time to age for a pint?

I will find blackstrap and have started to save dunder for future batches.

[OtisT]

Confused by the “1.5l or 1.5g”. 1.5L is a bit less than 1/2 gallon.

Did you add a fair amount of white sugar in your ferment? Many washes with white sugar are described as having a “sugar bite” to it that may be what you are describing. Just a guess.

For a pint of 60%, I personally use one stick, 3/4” x 3/4” x 2”. Maybe a little less. You can always add more, but taking it away is more difficult.

Otis

[thepopeofantelope]

Confused by the “1.5l or 1.5g”. 1.5L is a bit less than 1/2 gallon.

Did you add a fair amount of white sugar in your ferment? Many washes with white sugar are described as having a “sugar bite” to it that may be what you are describing. Just a guess.

For a pint of 60%, I personally use one stick, 3/4” x 3/4” x 2”. Maybe a little less. You can always add more, but taking it away is more difficult.

Otis

Yes, typo, ~.5 gal.

No white sugar, raw organic cane sugar and light molasses.

Thx those measurements are about 3 of my oak cubes. I'll report back when complete.