Rum: Backset, Dunder And Lees

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mikeac
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Rum: Backset, Dunder And Lees

Post by mikeac »

So I've been trying to come up with a better rum process, My first rum was damn good, but looking to improve to well...DAMN good. But I'm a little confused by these three terms and people seem to use a lot of them interchangeably so I'm looking to clarify:

Lees: Crap on the bottom of my primary fermenter I leave behind when i
siphon into a carboy to let it clear a little? ( I thought it was all dead
yeast, apparently a lot of it is still alive?)

Backset: (noun) Crap left in my bioler after I'm done a run.
(verb) adding the (noun) back into a wash as liquid in a new.
ferment

Dunder: now this is where the confusion comes in...I've heard people refer to both lees and backset (assuming I have them right) as dunder. So all I really know is that dunder is something rum specific added to the ferment recycled from the previous run/ferment.

It seems people seem to use either/or as dunder and claims it makes the rum much better. I'm not sure which is actually dunder, and which to add back to my rum...Both?
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Re: Rum: Backset, Dunder And Lees

Post by Husker »

Lees: Crap on the bottom of my primary fermenter I leave behind when i
siphon into a carboy to let it clear a little? ( I thought it was all dead
yeast, apparently a lot of it is still alive?)
Yes
Backset: (noun) Crap left in my bioler after I'm done a run.
(verb) adding the (noun) back into a wash as liquid in a new.
ferment
Yes and yes.
Dunder: now this is where the confusion comes in...I've heard people refer to both lees and backset (assuming I have them right) as dunder. So all I really know is that dunder is something rum specific added to the ferment recycled from the previous run/ferment.
Dunder == Backset. It depends upon which people you talk to. Most of the sour mash whiskey/bourbon use the term backset. While most of the rum folks use the term dunder.

Not sure why, but probably due to differences in language of the people who "most commonly" distilled each type. Whiskey/Bourbon was mostly done by the English speaking (in the beginning). Rum (or Rhum) was done by other people speaking other languages (Dutch / Portuguese / French? I am not sure which). That would be my hypothesis on why different words are used for much the same thing.

Also, I do not think dunder is used as a "verb" form, but I certainly could be wrong on that.

H.
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Post by mikeac »

That's kinda what I thought, but wasn't too sure. So for a little more confirmation, pretty sure I've read this multiple other places: If I take my backset/dunder add more sugar and molasses while hot, simmer for a coupla more min, wait till cool, add it back to the lees, top up with water then it'll start to ferment again and i'm on my way to REALLY good rum?
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Post by Husker »

mikeac wrote:That's kinda what I thought, but wasn't too sure. So for a little more confirmation, pretty sure I've read this multiple other places: If I take my backset/dunder add more sugar and molasses while hot, simmer for a coupla more min, wait till cool, add it back to the lees, top up with water then it'll start to ferment again and i'm on my way to REALLY good rum?
You will only want to add "some" of your dunder (well I can only comment on grain residue, backset). The backset is acidic. If you add too much, then you will end up with too low of a Ph, and things will not work correctly.

A good rule of thumb, is to add 1/4 to 1/2 of the volume as backset. On the 2nd generation, 1/2 is a "good" start, then on the 3rd and especially 4th generation and beyond, should not use 1/2, but should probably only use 1/4 to 1/3 volume of backset. This is what I have found to work well with UJSM. The first time I did it, I was adding back about 40%. Then after about 5 generations, things really slowed down, as things simply grew too acidic. I think getting to the proper Ph (using 1/2) on the 2nd run, is a good idea, but then it might be best to measure (strips), to make sure the Ph does not get too low. The 2nd time I did UJSM, I did 1/2 on the 2nd, then about 30% from that point on. I did 12 gens before dumping the whole thing (had all the low wines I wanted), and I never had any problems in the ferment. Things worked like clockwork.

I am sure that rum is a different beast. Also, many people have claimed that too much dunder will simply create a rum that is too strong in flavor. NOTE that with rum (depending upon your molasses), you will start to concentrate trace material, which CAN be bad for the yeast. Again, some dunder will help, but too much might actually be very bad, and you will end up sticking and not fermenting.

H.
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Post by mikeac »

Thanks Husker, That's a whole lotta help in that post!
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Post by junkyard dawg »

I've used 100% backset in grain mashes. It is too strongly flavored for my taste. I'd bet dunder in a rum wash would be the same, but haven't actually tried that...
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Post by HookLine »

Rum and dunder

http://groups.yahoo.com/group/Distillers/message/38852" onclick="window.open(this.href);return false;" rel="nofollow
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Post by mikeac »

Good Link!! I was wondering if anyone has tried to "clear" they're molasses before?? It's the first I've heard of it, but it would be nice to keep all that sludge outta my boiler.
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Post by HookLine »

There is a lot of good stuff on Yahoo distillers about rum. Look for posts by gnikomson2000 (aka Harry) and waljaco.

Haven't made rum myself, though I have just built a pot column so probably will one day.

••••••••••••••

Here is a (PDF) link to the 'Distillation & Denaturing, 1907' text referred to in the Yahoo post I linked to.

http://www.distillationgroup.com/distil ... 2/H002.pdf onclick="window.open(this.href);return false;" rel="nofollow
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Re: Rum: Backset, Dunder And Lees

Post by Freerum4life »

So I’m very new to this! Wondering how to get Dunder for first batch of rum! Do I just do a simple white rum for first batch and save the Dunder for the second batch? Also just to clear it up. a Dunder pit is Dunder put into a container and left to ferment naturally with whateveryeasts, bugs and wild critters are in the air? How is it stored?
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Re: Rum: Backset, Dunder And Lees

Post by Single Malt Yinzer »

Freerum4life wrote:Wondering how to get Dunder for first batch of rum! Do I just do a simple white rum for first batch and save the Dunder for the second batch?
Do your first batch the same as you would any other following batch you would do. After the first batch keep 10-25% of the volume of water you would normally use in a batch. For a 10 gallon batch keep 1.0 to 2.5 gallons of dunder for the next batch.
Freerum4life wrote:Also just to clear it up. a Dunder pit is Dunder put into a container and left to ferment naturally with whateveryeasts, bugs and wild critters are in the air? How is it stored?
https://homedistiller.org/wiki/index.php/Dunder" onclick="window.open(this.href);return false;" rel="nofollow
https://homedistiller.org/wiki/index.php/Lees" onclick="window.open(this.href);return false;" rel="nofollow

Dunder = Backset = Sour Mash = Stillage = Stuff left over in a boiler after a run.

There are some slight variations to how people use them as there's no Webster Dictionary defining these things super well. Dunder tends to be Rum specific, the rest tends to be more commonly used with Whiskey. Sour Mash most properly refers to the process of using backset but most people use them interchangeably.

Dunder can be used fresh or left to nature to allow for infection by bacteria. Fresh meaning either used shortly after a run or else refrigerated/frozen so that infections do not happen. Some people include spent lees in their dunder (agitate the stillage before collection), some let it sit to clarify. Most people keep in a carboy or to refrigerate or freeze a gallon milk jugs. The Wiki article has some links in to show you more.

What's best is what leads you to the product you like the best. Every choice you make will change the flavor profile of your Rum. Test and see what you like.
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Re: Rum: Backset, Dunder And Lees

Post by RedwoodHillBilly »

Single Malt Yinzer wrote: What's best is what leads you to the product you like the best. Every choice you make will change the flavor profile of your Rum. Test and see what you like.
Truer words have not been said. For My whisk(e)ys, I tend to use fresh backset, but have used infected backset as well. Both are good. For rum, I would tend to use an infected backset (dunder) to get more of the carboxylic acids, hopefully butyric (baby puke) acid which will give you some fruity esters.

To each their own. You will have to experiment and then make your own choice depending on the characteristics of the product you want to produce. That is part of the fun in this hobby (at least I think so).
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