“Demerara” sugar sounds like “them are rarer.” “There aren’t that many jokes about white sugar. But jokes about brown sugar….demerara! HAHAHAHAHAHA!! credit to @Cataska” was posted on Twitter by Alax Osborne on January 30, 2014. “Jokes about white sugar are rare, but jokes about brown sugar? Demerara….” was posted on Twitter by Andy Hirst‏ on January 31, 2014.
 
The demerara joke has been printed on several images.
 
         
Wikipedia: Brown sugar
Brown sugar is a sucrose sugar product with a distinctive brown color due to the presence of molasses. It is either an unrefined or partially refined soft sugar consisting of sugar crystals with some residual molasses content (natural brown sugar), or it is produced by the addition of molasses to refined white sugar (commercial brown sugar).
(...)
Turbinado, demerara and so-called “raw” sugars are made from crystallized, partially evaporated sugar cane juice and spun in a centrifuge to remove almost all of the molasses. The sugar crystals are large and golden-coloured. This sugar can be sold as is or sent to the refinery to produce white sugar.
         
Twitter
Alax Osborne
@AlaxOsborne
There aren’t that many jokes about white sugar. But jokes about brown sugar….
demerara!
HAHAHAHAHAHA!!
credit to
@Cataska
8:22 AM · Jan 30, 2014·Twitter Web Client
 
Twitter 
Andy Hirst‏
@HirstAndy
@carltonkirby Jokes about white sugar are rare, but jokes about brown sugar? Demerara…. #cgf
5:18 AM - 31 Jan 2014
   
Charlton Life—Forums
Jokes..
cafc999
February 2014
Jokes about white sugar are rare. Jokes about brown sugar? Demerara
 
Twitter
Eagle Plastering‏
@MarkJEagle
Jokes about sugar are pretty rare…but jokes about brown sugar, well, demerara…...
1:59 AM - 1 Feb 2014
   
Twitter
Jake ©raughwell‏
@CraughwellJ
You know, jokes about sugar are rare… But jokes about brown sugar, Demerara.
7:33 AM - 5 Apr 2014
   
Twitter
SORTEDfood‏
@sortedfood
You know, jokes about sugar are rare… but jokes about brown sugar, Demerara.
12:21 PM - 5 Apr 2014
     
Reddit—Dad Jokes
Jokes about white sugar are rare… (self.dadjokes)
submitted September 16, 2016 by JoeParks87
...but jokes about brown sugar, demerara.
COMMENTS
w1n5t0nM1k3y
Had to look it up on Google. Seems like demerara isn’t even the same thing as brown sugar.

Unlike brown sugar, which is just refined white sugar lightly bathed in a bit of molasses (this is a good thing to know, as you can just substitute brown sugar for white sugar with a bit of molasses added), Demerara sugar is a large-grained, somewhat crunchy, raw sugar with origins in Guyana (a colony formerly called ...
   
Reddit—Dad Jokes
Jokes about white sugar are rare (self.dadjokes)
submitted November 10, 2016 by sexualised_pears
But jokes about brown sugar, demerara
 
Twitter
Best Jokes Ever‏
@BestJokesEverUK
Jokes about white sugar are rare. Jokes about brown sugar, Demerara! #1pun
7:48 AM - 12 Mar 2017
         
The Scotsman (Scotland)
50 of the best jokes and one-liners from the Edinburgh Fringe
Published: 13:19 Friday 04 August 2017
(...)
“Jokes about white sugar are rare. Jokes about brown sugar, Demerara.” Olaf Falafel (2016)
 
Reddit—Jokes
Jokes about white sugar are rare.
submitted September 4, 2017 by Madbeef7
Jokes about brown sugar? Demerara.
 
Reddit—Oneliners
Jokes about white sugar are rare. Jokes about brown sugar, Demerara.
submitted October 17, 2017 by ariela99
 
Twitter
Brandon Robshaw‏
@BrandonRobshaw
Jokes about sugar are quite rare, aren’t they? But jokes about BROWN sugar - demerara…
3:38 AM - 9 Jan 2018
 
Twitter
LaffGaff‏
@LaffGaff
Jokes about sugar are rare.
Jokes about brown sugar - Demerara.
#funny #jokes #jokeoftheday
4:12 PM - 12 Jan 2018