What exactly is dunder?

[cornwhiskey]

What exactly is dunder? I've done some reading and some say it is the backset from a spirit run, some say it is the backset from a stripping run and others say it is the yeast cake that is left over after fermentation. So, which one is it?

[Hawke]

Dunder is backset from a molasses rum wash.

[LWTCS]

NO.

dunder is that smart feller that helps people here at HD

And what hawke said

[blanikdog]

Beat me to it, LW.

blanik

[Dnderhead]

""Dunder is backset from a molasses rum wash.""
I could argue that point but wont,,call it what you want.

[GrayGull]

Dunder is backset from a molasses rum wash.

What then is the yeast residue, etc., remaining in the fermenter when the completed wash is removed? Lees, perhaps. Good yeast nutrient for the next wash. My understanding is that this is called dunder.
Backset, I believe, is what is left in the boiler after distillation is finished.
['Terminological inexactitude' as our Prime Minister might say.]

[olddog]

All you neede to do is a Wikapedia search, and save your confusion.
Dunder is the yeast-rich foam leftovers from one batch of rum that is used to start the yeast culture of a second batch. It is the traditional yeast source in Jamaican Rum. Similar in process to sour mash in Bourbon whiskey, it is a crucial step in achieving an authentic rum flavor.

OD

[GrayGull]

Your advice is appreciated, thanks for te response.
Do you mean that 'dunder' is specific and exclusive to rum distillation?

[olddog]

Similar in process to sour mash in Bourbon whiskey, it is a crucial step in achieving an authentic rum flavor.

Backset/Dunder are similar, one is used for rum, one is used for bourbon.

[cornwhiskey]

All you neede to do is a Wikapedia search, and save your confusion.
Dunder is the yeast-rich foam leftovers from one batch of rum that is used to start the yeast culture of a second batch. It is the traditional yeast source in Jamaican Rum. Similar in process to sour mash in Bourbon whiskey, it is a crucial step in achieving an authentic rum flavor.

OD

So dunder is just the old yeast cake from a rum fermentation. While I'm new to distilling I'm calling bullshit on saying it contributes a great deal of flavor. I've repitched yeast a number of times in my homebrewed beers and it tastes the same each time. The flavor only changes when the yeast starts to mutate, this can take quite a few generations with some yeast. The only difference in taste when the yeast mutates is that you have a somewhat different yeast. I'm going to need a lot more compelling evidence than something that some unknown person wrote on Wikipedia. Wikipedia does have a lot of great information but there is also a lot bull on it as well.

My homebrew knowledge is akin to rads, kiwis, etc.. knowledge of distilling.

[HookLine]

I thought dunder was just the specific name for rum backset, the stuff left behind in the boiler after running a molasses based wash.

Maybe I been using the wrong term.

Though I would not take Wikipedia's word for it.

[MashMan]

I beg to differ on the "Dunder is the yeast-rich foam leftovers from one batch of rum that is used to start the yeast culture of a second batch" or the yeast cake etc etc. there are a multitude of recipes that use "dunder" UJSSM for the most common example and it is the skanky shite thats left in the boiler after a strippin or first run of a wash thats added back to the next wash, ie sour mash, to lower the ph, carry over flavour etc etc etc. I'm not sayin that the 'politically' correct term does not come from makin rum but what it is "most' commonly refered to "today"

MM.

[kiwistiller]

well it would be fair to say that the terms meaning varies... round here we normally use it to speak of rum backset don't we? Are there enough of us to just decide that this is what it means???

[olddog]

I'm going to need a lot more compelling evidence than something that some unknown person wrote on Wikipedia.

My reference to Wikapedia was to imply that you can do your own research rather than wait to be spoonfed, as confirmed by other posts the Wikapedia reference is generally correct.

[HookLine]

Google, and ye shall find...

Leftovers after running the wash, that are recycled back into the next ferment. It seems the definition is backset with the yeast still in it. IOW, they do not clear the ferment. Dunder provides nutrients, and enhances "character".
http://chestofbooks.com/food/beverages/ ... under.html" onclick="window.open(this.href);return false;" rel="nofollow

and

"a portion of the residue from the previous distillation, known in some countries as "dunder," is added to the mash."
http://chestofbooks.com/food/beverages/ ... ation.html" onclick="window.open(this.href);return false;" rel="nofollow

Also

A waste product of yeast production.
http://www.cropscience.org.au/icsc2004/ ... irchcj.htm" onclick="window.open(this.href);return false;" rel="nofollow

[cornwhiskey]

I'm going to need a lot more compelling evidence than something that some unknown person wrote on Wikipedia.

My reference to Wikapedia was to imply that you can do your own research rather than wait to be spoonfed, as confirmed by other posts the Wikapedia reference is generally correct.

Rather than being spoon fed!

I did my research and came up with different definitions of what dunder is (inlcuing Wikepedia). Therefore I came here to get a little clarification. If you read my first post you would have seen that. Don't go flinging crap until you've got your facts straight.

[blanikdog]

From the dark recesses of my grog sodden brain, I believe that dunder is the term for the residue of a molasses distilling run, and trub is the term for the yeast and other goodies remaining from the ferment and settling on the bottom. Any ferment I seem to recollect.

blanik

[HookLine]

Chill out everybody. It is just a word we are talking about here.

[goose eye]

round here if it been cooked an left in the kettle it called hot slops.
once you pop the cap hot slops can be used to add back cook or clean but mostly you just tryin to get it gone without leavein signs an getin burned

so im tole

[blanikdog]

Blanik has chilled. AND......loving it.

blanik

[crimsonwine]

I'm going to need a lot more compelling evidence than something that some unknown person wrote on Wikipedia.

My reference to Wikapedia was to imply that you can do your own research rather than wait to be spoonfed, as confirmed by other posts the Wikapedia reference is generally correct.

Cornwhiskey has a valid question....I too am confused what exactly dunder is...I researched here and Google extensively...and based on Wiki def. of "Dunder is the yeast-rich foam leftovers from one batch of rum that is used to start the yeast culture of a second batch." sounds more like Krausen to a home brewer than anything else...and if it is foam how the hell do you add gallons of it to your next ferment?

So it is either the yeast cake or whats left over from your boil....

For gods sake we are all learning here and is it so hard to just say what it is? This is a great site, but there is an overwhelming amount of info..and sometimes conflicting....we need to reach out for clarification....I know it's hard when you been doing this a long time its all easy for you to understand, you take it for granted...but I haven't even distilled my first batch so It is a little hard to grasp some of the terms until you actually do it...

All I want to do is simply distill a spiced rum...I just wish there was a simple recipe and instructions....they might be here....but it is buried and I spend HOURS every night reading and it can make your head swirl...

Cornwhiskey....thank you for asking the question! you are not alone....!!!

Oh BTW Wiki also says "it is the traditional yeast source in Jamaican Rum" indicates to me they are referring to the yeast cake...since the leftover of the boil would only contain dead yeast...and only be a nutrient for the next ferment...

[orpheus16]

Common usage around here seems to be the stuff left in the boiler after a stripping run of rum. But I just inferred this from context, so I might have misunderstood.
Rum talk in recipe development has a TON of great info on dunder, although no straight definition that i could find.http://homedistiller.org/forum/viewtopi ... 11&t=16491 apparently there is a good bit of rum that is made by letting the dunder age and pick up bacteria/fungus... I haven't tried that yet

[Dnderhead]

dunder-although on this site most refer hot slops/backset from rum as dunder,it is and not,
dunder means worthless/no good/or waste ( dunderhead-the guy in the corner wasted).in jamaica and other places where they refine
sugar they skim off the foam when boiling the sugar cane juice (rich in minerals adds flavors and is about 50% sugar), this and the foam from top of
the ferments is added for yeast,both are referred to as dunder.
not starting an argument but what is left in boiler is also dunder but that is not what is used in rum.
that is what is being dumped in rivers, ponds and on lands and is killing fish/wildlife,contaminating water supplies.

came back to add: they also use the scrappings from the inside of the coppers (copper kettles)
that is used for boiling down the cane juice as it caramelized.

[myles]

I believe the wiki definition is a new one, whereas the old one is that the dunder is what is left in the potstill after the alcohol has been removed.

It is refered to by JE Murtagh in The Alcohol Textbook as "dunder is old stillage that has been stored in open tanks to allow development of a strong bacterial flora"

Most of the folks that are using dunder at the moment are regarding it as in the older definition above. The concensus seems to be that it contains unfermentable sugars and dead yeast. When stored in a "dunder pit" it develops a bacterial colony, that feeds on these sugars and yeast cells. This in turn produces many desireable flavour components that are considered essential in 'Heavy' rums.

This bacteria is used during the fermentation as explained in the Arroyo patent. Some folks add some dunder to their spirit run or charge their thumper with it. This is a flavour enhancement exercise.

When used in the fermentation - under the correct conditions - it will form a symbiotic relationship with the yeast.

[Bushman]

What exactly is dunder? I've done some reading and some say it is the backset from a spirit run, some say it is the backset from a stripping run and others say it is the yeast cake that is left over after fermentation. So, which one is it?

Actually I think this term has been miss-used along with others. I for one miss-used it as I thought it was the yeast cake left over from fermentation. I just tried to link from here to the HD Wiki but wouldn't let me so I backed out and linked from the beginning. We do not have a section dedicated to terminology and I think our wiki needs a lot of work. I am not trying to make more work for the powers to be, but maybe having a section just dedicated to terms that we can all agree to. I actually do a lot of google searching even though this site has the most information at times I find it hard to decipher.

[Dnderhead]

http://books.google.com/books?id=_lmFzF ... er&f=false" onclick="window.open(this.href);return false;" rel="nofollow

[Paulo Moreira]

I think this doubt is part of a large number of people do not really understand the meaning of Dunder, and is a word that is not part of the English dictionary.
I'll try to explain what is done here with cachaça in Brazil.
When we finish the fermentation, or when the Brix go zero, let the wash for six hours before removing the liquid to the distiller, it makes the dough fermentation decant at the bottom of the vat, for a higher output than the bottom we remove the wash, preserving an amount of about 20% of the total, this output of the fermentation tank is situated at a strategic height, which ensures to removal the wash without residue dragging of bottom.
This residue at the bottom is loaded with fresh sugarcane juice, typically 17 ° Brix, this means that there is an increase of wild flora yeast instead of baking that started the fermentation, this guarantees the flavor and aroma typical of each producer, because we know that in each place or region has a tipycal biological characteristic flora.
Normally this process is repeated for 7 to 10 times, after this period is restarted a new fermentation with selected yeasts. Because the competition with the microorganism contaminants increases significantly.
The residue distilled here in Brazil we call the slop (vinhoto), it's often used as fertilizer at the plantation of sugar cane, but as the harvest only have 150 days in the last month of harvest keep this whole stillage which still contains plenty of cachaça congeners for reuse as I will explain below.
The cachaça obtained in industrial distillation columns organoleptic despite being correct, or is chemically a good product, it is weak in terms of flavor and aroma and can be purchased in large lots in bulk for a price around US$ 0,50, one way to give quality of aroma and taste of this product is mixed at a ratio of 70% slop with 30% industry cachaça and the mixture is redistilled. Becoming a product with commercial value of approximately US$ 4.50. it is replaced by the characteristics of a handmade product.
My goal was not to explain the meaning of Dunder, but trying to show the effect of two situations that arise here in this post

[Dnderhead]

according to Jamaican dictionary it means waste from processing sugar cane.
can be from still/ferment or the foam from boiling the juice witch is often added to the ferment.
as this has much minerals/sugar and flavor.
( http://books.google.com/books?id=_lmFzF ... er&f=false" onclick="window.open(this.href);return false;" rel="nofollow)

[freshwaterjellyfish]

..crazy thread..great info, even tho conflicting.
It brings me to a question:
For a great rum, is it appropriate to clear my mash of yeast with chitosan and kieselsol? Ive read when yeast is boiled(distilled), it will give the distillate a foul flavour..and if so..would it spoil the yeast/bottom stuff left in the carboy?..assuming i was gonna use it for whatever it may be good for (yeast rejuvination for example)..
Ive used this clearing stuff only once seemed to work but i cant say i liked what i got (mostly org cane sugar used).
Someone please school me!!

[bearriver]

..crazy thread..great info, even tho conflicting.
It brings me to a question:
For a great rum, is it appropriate to clear my mash of yeast with chitosan and kieselsol? Ive read when yeast is boiled(distilled), it will give theYstillate a foul flavour..and if so..would it spoil the yeast/bottom stuff left in the carboy?..assuming i was gonna use it for whatever it may be good for (yeast rejuvination for example)..
Ive used this clearing stuff only once seemed to work but i cant say i liked what i got (mostly org cane sugar used).
Someone please school me!!

First off, use a recipe from the tried and true. There's gotta be around a half dozen Rum recipes in there. It takes out all the guess work so you can focus on much needed research. Right now you shouldn't be making experimental washes, at least until you get a grasp of the eintire process.

You certainly ressurected this thread from the dead. I think you have a terminology misunderstanding. Lees in your fermenter stay there and do not go into the boiler (Typically). They may also be diacarded depending on your prefrence. Boiled yeast can be saved and frozen for use as yeast nutrient as well. You have plenty of options.

Some people distill the whole thing in a double boiler to avoid scorching the solids. The flavor produced from this method is liked by some, and not by others. Again it is a matter of personal prefrence.

Personally, I wouldnt ever use clearing agents. Patience is a better tool for that particular job.