How does the aroma and taste of rubber get into a few rums?

Sulfur components in molasses makes this burn rubber smell. Copper pot still can remove it from steam during distillation process. Also the distillation in a multicolum still removes most aromas including this one.

Thanks vomi1011: I just somehow knew that the rubber taste is much more complex than my simple assumption based upon an unaged clairin that has no molasses in the entire process. I was thinking that these are very poor people where this originated and what would they do. Cane juice gathered in rubber tires seemed like a simple answer and could very well be true. I had to look up how on earth sulphur can get into molasses. When sugar cane is too young and molasses is made from it, sulphur dioxide is added to it as a preservative. In other words, this is really cheap molasses. And knowing that cane juice must begin fermentation within one hour of being extracted so that it won't spoil, there is also a high probability that sulphur dioxide was added to the cane juice that was used to make my batch of Clairin Vaval. This also makes me wonder about industrial grade cachacas. I wound up pouring half of my bottle down the drain. How on earth this batch got past Luca to be branded as Velier is beyond my imagination. This is also the ONLY Velier branded Clairin that was horrible. Two were superb and one was inoffensive. As for the distillation process, I had to dig my empty bottle of Clairin Vaval out of the garbage to find out and read all of the details on the back label. It states pot distillation, but does not specify copper pot stills. I would imagine that if they actually used copper pot stills, they would want to toot their horn on this as well. The chemical reaction between the copper and dissolved sulfides makes perfect sense on how that undesirable element can be removed via steam. Thanks for the inspiration into my further research on this!

Hey Paul, for you further research, look out for some table of esters and their smell. The most aromas come from esters, if a rum contains a lot of ester the higher is the chance to get some wired aromas like rubber, tar, diesel or glue in it, in my case I find it very interesting and I like it. Pot still rums contain more esters than a column one, with the last it's possible to create a "clean" rum. Caroni for example, their rum is very dirty because their pots hade sometimes overcooked and the molasses burned on or they don't do a proper cleaning. I love it! (A Swiss rum importer told me this story) That's the problem (not really) with Swiss rum distillers, too clean, too perfect, super spirit but a lack of typical rum aromas. Also very interesting the topic of using dunder or muck hole for the fermentation. I don't put in links, I know you don't like them. ;-)

Rene: The Plantation Rum website now has very detailed information on special releases to include esters and added sugars. This foray into "rubber tastes" has now made me more aware of what esters is really all about. When molasses is processed from young sugar cane or newly extracted cane juice approaches being more than one hour old, sulphur dioxide smoke is added as a preservative. Column distillation or copper pot distillation can remove most of this element. And after doing research on Haitian clairins, I now realize how some rotten tropical fruit notes can wind up in the product. To speed up fermentation, some of these tropical elements are added to the mash! No wonder, lots of Jamaican rums have rotten banana notes. And no wonder that multiple column distilled rums like Bacardi won't offend anyone except us true rum lovers who want flavor! My next research will be to try and find as many rums that are copper pot distilled to remove that rubber taste that I hate. I like flavors in my rums, but I do draw the line with the really dirty ones like Clairin Vaval. Thanks for the inside scoop on dirty Caronis!!! That bottle of Caroni Trinidad 17-Year 110 Proof can remain under that locked glass case several miles away. It is probably not from Velier, which is why no one is buying it at the bargain price of only $190 US. It normally goes for $350 US. With Caronis being dirty rums, local Trinnies did not like them for the most part, so they went out of business. I think that Angostura may have also bought out most of them, but the remaining barrels and bottles now go for a small fortune because they are gone forever and this world has a few dirty rum lovers that can afford them. Another one of the reasons that I don't like links is that one of the links on here from a few months ago was caught by my anti-virus software as being very dangerous. Coming from an IT and engineering background, I rapidly close down those links and seldom trust their sources again.

This actually where I'm truly amazed by chemistry, that there is some aroma or taste can be present in a rum just from fermentation and distillation of the molasses. While I'm aware of the fact that there are many methods of adding tastes (adding rotten fruits to the dunder like some Hampdens, finishing in a specific barrel like HC Union and many other or brutally adding the post-production spicings), it's just fantastic that some esters come from the fermentation and distillation of the molasses itself. For me this is the "purest" source of rum flavours.

Rene: Two days ago, you responded with an incredibly inspirational post on esters and their smells. Also, you mentioned a new term that I had never heard of that also means dunder. This all really got me into digging in! Several articles on Cocktail Wonk covered these topics extensively. The same esters in different concentrations yield different tastes. One needs to be very well versed in organic chemistry to fully comprehend these topics, and that was the most difficult of all college courses. I had thought that thermodynamics and dynamics were the toughest until I heard about organic chemistry. So with high ester amounts being desirable, what I have found from reading up on this is that it can be compared to writing computer code. As one increases structured programming, the code gets easier to read up to a point. After that point, the readability nose dives. The same holds true for esters. The taste keeps getting better as ester amounts increase, but at a certain point whereby rubber and glue and petrol dominate, then this is no longer desirable to most. I had one engineer disagree with me on excessive structured programming, just like not many rum drinkers love the dirty ones. I also read about a Jamaican rum with ester counts of 1600 grams per HL AA, but these were never meant to be consumed. A Facebook posting from Richard Seale even mentioned this, and was reprinted in one article from Cocktail Wonk. His rums are often used to tame down Jamaican rums with excessive funk, and now I can see why. Reading about dunder and muck holes, the original makers of Jamaican funk rums must have just lucked out by experimenting. They had absolutely no idea that they were delving into advanced organic chemistry. And I am guessing that including the heads of bats and goats into the dunder is only legend. However, The Rolling Stones recorded their Goats Head Soup album in Jamaica, so the dunder legends most certainly inspired that title. Thanks again for the inspiration! One learns something new every day! However, I still have not found the chart that separates the very pleasant esters from the ones at the far end that make for dirty rums. Just let me know exactly what to Google.

Awesome picture, Rene!

It's an original picture from the album.

Rene: That album was done during times of turmoil within the band and I never liked most of it and have never owned a copy. Much better versions of Silver Train and Winter can be found on the Carla Olson & Mick Taylor releases. Mick was stuck in the background for GHS. Goats are everywhere in Jamaica because they are "sure footed" and can stand on steep inclines.