Dunder vs Backset vs Stillage

[whaleShark]

When producing rum, how are Dunder, Backset, and Stillage different - or are they?

 

[stillwagon]

I could be wrong, but I believe dunder is rum specific.  Backset I have heard mostly referred to in whiskey settings, and stillage is pretty generic.

 

[whaleShark]

So, probably all means the same thing - thanks...

Charleston, haven't been there but used to get close. Had family in Coos Bay, would make the drive from Long Beach 'cross the bridge and then head down the coast...good memories...

[Sudzie]

I've understood it as: Backset, the fresh liquid from a whisky (grain) striping run and used for a sourmash fermentation. Dunder, the not so fresh (spoiled) liquid from a rum striping run that would be used in a rum fermentation and Stillage what is left in the still (grains and liquid) from a whisky striping run and used as feed. We use all three processes.   But with that said I'm open to correction.....

[RobertS]

My understanding is that you're correct. Stillage is what's left in general, backset is immediately used for nutrients in the next ferment, and dunder is allowed to 'spoil' to act as a mother source for bacteria in rum.

[Gwydion Stone]

Stillage is whatever is left in the still at the end of a run, no matter what the product and no matter what you do with it, re-use it or discard it.  

Dunder is specifically rum stillage which is allowed to open-ferment and take on specific bacteria and yeasts that result in rum's high-ester profile.  It works like a sourdough starter. The funkier the dunder gets over time, the more high-ester the resulting rum.  

Backset is specifically whiskey stillage (maybe bourbon only?) synonymous with sour mash.

[Rum]

On 5/31/2016 at 1:36 PM, Gwydion Stone said:

Stillage is whatever is left in the still at the end of a run, no matter what the product and no matter what you do with it, re-use it or discard it.  

Dunder is specifically rum stillage which is allowed to open-ferment and take on specific bacteria and yeasts that result in rum's high-ester profile.  It works like a sourdough starter. The funkier the dunder gets over time, the more high-ester the resulting rum.  

Backset is specifically whiskey stillage (maybe bourbon only?) synonymous with sour mash.

In my understanding the term dunder refers to rum stillage. I think that it generally means what is left after a stripping run not a spirits run. 

The pits used to create high ester Jamaican style rums are generally referred to as muck pits. They contain dunder as well as many other things. A great article on the subject is http://cocktailwonk.com/2016/03/days-of-dunder-setting-the-record-straight-on-jamaican-rums-mystery-ingredient.html

[biodzldan]

On 5/28/2016 at 10:39 PM, Sudzie said:

I've understood it as: Backset, the fresh liquid from a whisky (grain) striping run and used for a sourmash fermentation. Dunder, the not so fresh (spoiled) liquid from a rum striping run that would be used in a rum fermentation and Stillage what is left in the still (grains and liquid) from a whisky striping run and used as feed. We use all three processes.   But with that said I'm open to correction.....

Do you mind if I ask: do you sterilize the dunder before adding to the fermenter or allow the bacterial to keep doing their thing along side the yeast?

[Rum]

On 5/31/2016 at 1:36 PM, Gwydion Stone said:

On 9/3/2016 at 0:06 PM, biodzldan said:

Do you mind if I ask: do you sterilize the dunder before adding to the fermenter or allow the bacterial to keep doing their thing along side the yeast?

We put the dunder into the mash tank with the molasses while it is hot from the still. No bacteria is living in it at that point. When distilleries use a muck pit they want the bacteria to be alive as it goes into the fermentors. 

[nabtastic]

On 8/25/2016 at 3:43 PM, Rum said:

In my understanding the term dunder refers to rum stillage. I think that it generally means what is left after a stripping run not a spirits run. 

The pits used to create high ester Jamaican style rums are generally referred to as muck pits. They contain dunder as well as many other things. A great article on the subject is http://cocktailwonk.com/2016/03/days-of-dunder-setting-the-record-straight-on-jamaican-rums-mystery-ingredient.html

Dunder is stillage that has been left to secondary biological activity as Gwydion Stone said.  Clostridium is probably the most ubiquitous.  It's used in a similar manner to backset (rum v whiskey vernacular).  There is no need to pasteurize or sterilize (your mash tun isn't sterilizing btw) but I don't know of any rules one way or the other. 

Stillage is a bastardized term for distillation effluent (vinasse is specific to rum to my knowledge).  Backset is most commonly used to refer to the effluent (stillage...) that is added to the subsequent mash.  However, backset is used for 2 primary purposes, 1) to reduce the total water usage by the DSP and 2) to acidify the mash to help prevent bacterial infections - theoretically helping to mitigate flavor variances between batches. 

{not trying to step on toes, just offering my 2c...also just realized how old the OP is..}

[Rum]

On 10/6/2016 at 7:53 PM, nabtastic said:

Dunder is stillage that has been left to secondary biological activity as Gwydion Stone said.  Clostridium is probably the most ubiquitous.  It's used in a similar manner to backset (rum v whiskey vernacular).  There is no need to pasteurize or sterilize (your mash tun isn't sterilizing btw) but I don't know of any rules one way or the other. 

Stillage is a bastardized term for distillation effluent (vinasse is specific to rum to my knowledge).  Backset is most commonly used to refer to the effluent (stillage...) that is added to the subsequent mash.  However, backset is used for 2 primary purposes, 1) to reduce the total water usage by the DSP and 2) to acidify the mash to help prevent bacterial infections - theoretically helping to mitigate flavor variances between batches. 

{not trying to step on toes, just offering my 2c...also just realized how old the OP is..}

I'm going to have to disagree with you on this one. The Jamaican rum distilleries will tell you that dunder is stillage. When left to biological activity it is referred to as a muck pit. 

There is a lot of disagreement and confusion on the meaning of the different terms so there may not be a consensus. I am going to go with the definitions of the Jamaicans since they are the ones using the muck pits that many mistakenly (in my belief) call dunder. 

[nabtastic]

ok so:

muck pit=dunder  dunder=stillage with a secondary biological inoculum  stillage-effluent effluent=backset 

many places use dunder/muck pits/containers of liquids + nutrients + microorganisms ... I even ran across a "dunder from downunder" but that may have been on a different forum.. anywho, the names change depending on how puffy you want to make your chest/brand but the definitions/uses stay the same.  

No matter what you call it, effluent discharge from rum left to undergo a secondary bio-cycle that is used to produce heavy ester rums are dunder/muck pit (I've not heard the term before but I've never been to Jamaica)

effluent discharge used to acidify(and I suppose and nutrients?) a subsequent mash is just regular old stillage=effluent=backset but it does not = dunder or muck pit because it does not utilize a secondary "fermentation,"  

 

Final comment before I shut up and make rum is:  call it what you want, as long as your audience knows what your meaning is it's fine (until a rule says otherwise - and there are plenty of rules).  In my opinion we spend way to much time debating nuances and who's terroir can beat up someone else's terroir than discussing how to actually make damn good booze. 

 

[I put fermentation in quotes because I don't know if dunder/muck pits are strictly anaerobic or if they use respiration as well - in any case fermentation in this case, does not come from yeast and it's unlikely to produce any ethyl alcohol though many other alcohols are likely formed]

[Coriolis]

So here's a question...do you add the dunder (or whatever you want to call it) at the start of the fermentation or towards the end after the yeast have done their thing in terms of alcohol production but still leaving time for esterification? 

I would of thought that this might of reduced the risk of poor yield but still give the funky flavours we're after.

[Florida Cracker]

I add mine right before it goes into the boiler to strip. If you keep your still in full reflux for an hour or two you should get plenty of esterfication

[nabtastic]

From the training material at IBD (Institute for Brewing and Distilling):

"Fermentation can be from naturally occurring yeasts and bacteria in the molasses feed stock or with cultured yeast and bacteria. In some countries still residues (stillage) are allowed to ferment by natural bacterial infection to produce “dunder” which is then added back (backset) to subsequent molasses fermentations. Such bacterial fermentations add desirable congeneric acids and esters to the alcoholic yeast fermentation, particularly for heavy rums. However this traditional Caribbean practice is now seldom used."

Dunder Caribbean term for the nonvolatile residue from rum distillation, which during storage supports the growth of a mixture of micro-organisms.  When stored dunder is added with yeast to a subsequent fermentation, these organisms provide a richer flavour to the rum than would yeast alone.

Stillage The mixture of unfermented solids and liquid remaining after distillation of alcohol from a wash/beer. Thin stillage is the liquid portion of stillage which has been separated from the solids by screening or centrifugation. In molasses and grape juice distillation the term vinasse may be used instead of stillage.