You see, it all started when a guy at Rum Ratings posted a public question to me. Like so many rum buyers, this poster was in the habit of checking the Master Sugar List to avoid the phonied up sugar bombs. He'd noted there were two postings for Bermudez: the Pirate at 0g of sugar, and moi at 26g!
This was indeed significant.
So I immediately posted that I'd contact Wes, the Pirate, and suggested we both retest the Bermudez. I did, and again confirmed the 26g reading; meanwhile the Pirate advised me that he too had seen the difference, had retested and he too again got, yup, 0g of sugar.
WTF?
Of course this is huge difference. I suggested to Wes that this might be the first proof that certain distillers "adjust" their rums differently for different markets. The Pirate is UK based, while I of course live not under gray skies but in the Paradise of South Florida. The American sweet tooth is well known.
Wes then stated that he believed that the distillers were now keenly aware of the sugar issue, and were substituting glycerine. The assumption is that glycerine evades the common hydro test, and further, that glycerine is not tested for by governments.
A dilemma?
Which is it: different amounts of sugar for different markets, or the substitution of glycerine? Or both? I had to know. Natch, I contacted Richard Seale, who advised the following:
Addenda, 12/4: Richard added..."Glycerine has been used for years in spirits for its sweetness and effect on mouth feel. I am quite sure you will find it in many vodkas.
It is used in rum as well. There are tests available on the internet showing it in Angostura and Don Papa.
Glycerine has about 2/3rds of the sweetness of sugar but its generally used in very small amounts - less than 1g/l. So it would not affect the hydrometer nor create the syrup like effect of large amounts of sugar. But it does seem to have a noticeable effect on mouth feel even at very low doses. Hence its popularity in vodka.
Note, some sherries like oloroso sherry have large amounts of glycerine (helps explain why oloroso tastes quite sweet despite the low sugar) and rums/whiskies could end up with trace amounts of glycerine if aged in these casks. I have seen a test result of a reputable Scotch Whisky with a trace amount of glycerine which almost certainly came from the sherry cask. Seems being very non volatile it will remain in an empty cask and find its way to the newly filled spirit."
"Note, glycerine is a fermentation by product and present naturally in all wines. The high level in oloroso sherry is natural and particular to that fermentation. It is not added."
So what to think?
Wes/Pirate position is clear and this is surely possible, but only if very large amounts of glycerin is added. For now I'm going to take the position that sugaring varies by market, and here's why...
1. Seales seems to be saying that glycerine is used in very small amounts (say 1g or less). He believes that small amounts of glycerine may transfer for those very, very few rums that use ex-oloroso sherry barrels.
2. These small amounts - while very effective at creating "smoothness"/mouth feel - would add almost no sweetness, assuming that Seales is correct in that glycerin is but 2/3rd's as sweet as sugar.
3. All of my initial research indicates that glycerine's primary effect - even in small quantities - is to improve mouth feel. Apparently glycerine also increases density and "thickness". Thus it is commonly used as a thickener.
And that is the rub. Can glycerin enough to substitute for sugar's sweetness, not also result in excessive density/thickness? For now, I do not believe glycerin is used to replace sugar, but your opinions are welcome...
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https://en.wikipedia.org/wiki/Glycerol
http://homedistiller.org/aging/aging