Do genuinely sweet (not sweetened) rums exist?

The sugars that are being fermented are generally complex sugars, these are left behind when you distill, so even if you have lots of unfermented sugar it wouldn't pass through into the distillate. Diluted ethanol can trigger responses in taste as "sweetness" but this isn't from sugar, it's the way that our brain perceives the taste. You can, of course, pick up sugars from cask maturation that are not considered "added", these are natural sugars found inside the wood that is dissolved by the spirit as it interacts with the cask during maturation. I don't mean sugars from used casks that have previously held other sweet alcohol, such as a PX sherry, but from the actual wood. The amount of sugar a spirit will take from the wood depends on the cask type and what it has previously held, as well as other factors such as the entry proof of the spirit as it is filled in to the cask.... ....interesting (or not, depending on your view) reading here if you want to see the effect the alcoholic strength on cask entry has on the resulting maturation and flavour of a spirit: http://whiskyscience.blogspot.co.uk/2013/01/alcohol-strength.html (yes it's whisky, but it's the same game. Many rum producers dilute down to around 65% abv on cask fill for the same reason)

Thanks for the interesting explanation. Makes a lot of sense. Any recommendation for rums that are naturally sweet due to cask maturation?

Oh no! Don't let Capn Jimbo see this post. R.L. Seale 10 year is a good starting point.

Let's be accurate. The idea that there are "natural sugars" in a wood cask, that somehow leach out into the spirit is, well, incorrect. There are no natural sugars per se. The aging of any spirit - scotch or other whiskeis, or bourbon is truly an art that has been developed over a couple hundred years. An oak barrel must first be prepared so that it will breath, filter the spirit both via the wood fibers and any created charcoal (charred) layer, but most important to participate in the additive, substractive and interactive processes that go on at different rates. . Back to the myth of "natural sugar"... . New oak has none. What does happen is that new wood is made up - among other things - of celluose and lignin. No "natural sugars" per se. First the wood staves must be steamed or heated so that it can bent . Now when the assembled barrel is then charred (as it must for the bourbon barrels) a couple of things happen. The cellulose is broken down into into component sugar molecules, which then carmelize (sweeten), and the lignin likewise is changed by heat into vanillan (which is perceived as a faint vanilla flavor). Whisky.com discusses this: . "If the casks were made from this wood, you would get a tight container, but the whisky couldn't mature. From a maturation standpoint, the wood is still dead. Only the following thermal treatment breathes life into the wood. This is a combined process. Only with heat the wood can be bent into the typical cask shape. During 'toasting', the wood is heated up to 200°C in a big oven for approximately 30 minutes, and the firm wood structure is broken up, cellulose is split into wood sugar and caramelises, and the Lignin is partially converted into Vanillin. The cask begins to live in terms of maturation. After the cask has been bent into shape, the inside of the cask is burned (charred) for 3 to 5 minutes and extinguished with water." . Bottom line: . 1. New oak contains no natural sugars. It is the preparation that chemically creates sugars and carmelizes them. These, along with the vanillans are in part transferred to the rum as part of the traditional aging of whisky and bourbon. 2. Probably 95% (or more) of rum is aged in used bourbon barrels. As once used barrels, most of the created sugars/vanillans have already been removed by the first fill of bourbon over two years. 3. Thus it is fair to say there are NO naturally sweet rums, unless of course you consider most bourbons sweet. Barrels are quickly used up, with most of the components removed by the bourbon - with bastard rum having to be aged in used bourbon barrels, with less and less of the additive, subtractive and interactive processes occuring. Carry on.

Sorry, the link, well worth your time if you want to understand why rum should be no more "naturally sweet" than whisk(e)y or bourbon: https://www.whisky.com/information/knowledge/production/details/maturation-in-casks.html

Noone said rum was more naturally sweet than whisky, but aged spirits will contain some sugars that are disolved by the spirit during maturation. It doesn't make them sweet buy it does allow some sugar to get into the final spirit, as well as other solids such as fats. Even your sugar tests allow for a 0-5g/l range as "no added sugar". It's not realistic to state that the majority of used casks that previously held bourbon have already had all sugars in the wood subtracted by the initial fill, and even new wood contains hemicellulose which can be subtracted by new make spirit, which is indeed a solvent. Fat as bottom line: maturing spirit subtracts some naturally occurring sugars from its cask, it may be minimal or not, but it still happens. Of course various links to various websites can be provided to back up various positions on the argument. I like to belive the ones that show scientific figures as evidence ;-) Doesn't make rum naturally sweet, it's a spirit so is not.

Let's be clear about the 0-5g this poster cites as meaning "no added sugar". . First of all, that reflects just one tester's protocol. Richard Seale is quite clear that dissolved wood solids (not sugar) may (a) may account for 1-2g of the the test - but - only for well aged rums. In younger or new rums, any reported number is all sugar. . Please also note how many aged rums test out at 0 grams (not a range like 0-3, or 0-5), so the idea that 0-5 grams means "no sugar" is a misrepresentation (as made clear in the preamble to the test list). I would also add that our "Che" did a VERY thorough tests of known pure and unadulterated rums (one white and one aged) and noted that even 1g of sugar could be detected on the palate, that 5g had notable effects, and that any more than that quickly degraded the profile by smothering it. . For the Master List and Che's test, just visit the "Sugar" section at the Forum.

On the other hand, Scotch aged in sherry and port casks, for example, are rather sweet, with no deliberately added sugar (that is, no sugar added after "aging" to make the rum "premium"). So could you age rum in sherry or port casks and such?